/* * Copyright (C) 2008 Tobias Brunner * Hochschule fuer Technik Rapperswil * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2 of the License, or (at your * option) any later version. See . * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * for more details. * * $Id: kernel_klips_ipsec.c 4793 2008-12-11 13:39:30Z tobias $ */ #include #include #include #include #include "pfkeyv2.h" #include #include #include #include #include #include #include #include #include "kernel_klips_ipsec.h" #include #include #include #include #include #include #include /** default timeout for generated SPIs (in seconds) */ #define SPI_TIMEOUT 30 /** buffer size for PF_KEY messages */ #define PFKEY_BUFFER_SIZE 2048 /** PF_KEY messages are 64 bit aligned */ #define PFKEY_ALIGNMENT 8 /** aligns len to 64 bits */ #define PFKEY_ALIGN(len) (((len) + PFKEY_ALIGNMENT - 1) & ~(PFKEY_ALIGNMENT - 1)) /** calculates the properly padded length in 64 bit chunks */ #define PFKEY_LEN(len) ((PFKEY_ALIGN(len) / PFKEY_ALIGNMENT)) /** calculates user mode length i.e. in bytes */ #define PFKEY_USER_LEN(len) ((len) * PFKEY_ALIGNMENT) /** given a PF_KEY message header and an extension this updates the length in the header */ #define PFKEY_EXT_ADD(msg, ext) ((msg)->sadb_msg_len += ((struct sadb_ext*)ext)->sadb_ext_len) /** given a PF_KEY message header this returns a pointer to the next extension */ #define PFKEY_EXT_ADD_NEXT(msg) ((struct sadb_ext*)(((char*)(msg)) + PFKEY_USER_LEN((msg)->sadb_msg_len))) /** copy an extension and append it to a PF_KEY message */ #define PFKEY_EXT_COPY(msg, ext) (PFKEY_EXT_ADD(msg, memcpy(PFKEY_EXT_ADD_NEXT(msg), ext, PFKEY_USER_LEN(((struct sadb_ext*)ext)->sadb_ext_len)))) /** given a PF_KEY extension this returns a pointer to the next extension */ #define PFKEY_EXT_NEXT(ext) ((struct sadb_ext*)(((char*)(ext)) + PFKEY_USER_LEN(((struct sadb_ext*)ext)->sadb_ext_len))) /** given a PF_KEY extension this returns a pointer to the next extension also updates len (len in 64 bit words) */ #define PFKEY_EXT_NEXT_LEN(ext,len) ((len) -= (ext)->sadb_ext_len, PFKEY_EXT_NEXT(ext)) /** true if ext has a valid length and len is large enough to contain ext (assuming len in 64 bit words) */ #define PFKEY_EXT_OK(ext,len) ((len) >= PFKEY_LEN(sizeof(struct sadb_ext)) && \ (ext)->sadb_ext_len >= PFKEY_LEN(sizeof(struct sadb_ext)) && \ (ext)->sadb_ext_len <= (len)) /** special SPI values used for policies in KLIPS */ #define SPI_PASS 256 #define SPI_DROP 257 #define SPI_REJECT 258 #define SPI_HOLD 259 #define SPI_TRAP 260 #define SPI_TRAPSUBNET 261 /** the prefix of the name of KLIPS ipsec devices */ #define IPSEC_DEV_PREFIX "ipsec" /** this is the default number of ipsec devices */ #define DEFAULT_IPSEC_DEV_COUNT 4 /** TRUE if the given name matches an ipsec device */ #define IS_IPSEC_DEV(name) (strneq((name), IPSEC_DEV_PREFIX, sizeof(IPSEC_DEV_PREFIX) - 1)) /** the following stuff is from ipsec_tunnel.h */ struct ipsectunnelconf { __u32 cf_cmd; union { char cfu_name[12]; } cf_u; #define cf_name cf_u.cfu_name }; #define IPSEC_SET_DEV (SIOCDEVPRIVATE) #define IPSEC_DEL_DEV (SIOCDEVPRIVATE + 1) #define IPSEC_CLR_DEV (SIOCDEVPRIVATE + 2) typedef struct private_kernel_klips_ipsec_t private_kernel_klips_ipsec_t; /** * Private variables and functions of kernel_klips class. */ struct private_kernel_klips_ipsec_t { /** * Public part of the kernel_klips_t object. */ kernel_klips_ipsec_t public; /** * mutex to lock access to various lists */ mutex_t *mutex; /** * List of installed policies (policy_entry_t) */ linked_list_t *policies; /** * List of allocated SPIs without installed SA (sa_entry_t) */ linked_list_t *allocated_spis; /** * List of installed SAs (sa_entry_t) */ linked_list_t *installed_sas; /** * whether to install routes along policies */ bool install_routes; /** * List of ipsec devices (ipsec_dev_t) */ linked_list_t *ipsec_devices; /** * job receiving PF_KEY events */ callback_job_t *job; /** * mutex to lock access to the PF_KEY socket */ mutex_t *mutex_pfkey; /** * PF_KEY socket to communicate with the kernel */ int socket; /** * PF_KEY socket to receive acquire and expire events */ int socket_events; /** * sequence number for messages sent to the kernel */ int seq; }; typedef struct ipsec_dev_t ipsec_dev_t; /** * ipsec device */ struct ipsec_dev_t { /** name of the virtual ipsec interface */ char name[IFNAMSIZ]; /** name of the physical interface */ char phys_name[IFNAMSIZ]; /** by how many CHILD_SA's this ipsec device is used */ u_int refcount; }; /** * compare the given name with the virtual device name */ static inline bool ipsec_dev_match_byname(ipsec_dev_t *current, char *name) { return name && streq(current->name, name); } /** * compare the given name with the physical device name */ static inline bool ipsec_dev_match_byphys(ipsec_dev_t *current, char *name) { return name && streq(current->phys_name, name); } /** * matches free ipsec devices */ static inline bool ipsec_dev_match_free(ipsec_dev_t *current) { return current->refcount == 0; } /** * tries to find an ipsec_dev_t object by name */ static status_t find_ipsec_dev(private_kernel_klips_ipsec_t *this, char *name, ipsec_dev_t **dev) { linked_list_match_t match = (linked_list_match_t)(IS_IPSEC_DEV(name) ? ipsec_dev_match_byname : ipsec_dev_match_byphys); return this->ipsec_devices->find_first(this->ipsec_devices, match, (void**)dev, name); } /** * attach an ipsec device to a physical interface */ static status_t attach_ipsec_dev(char* name, char *phys_name) { int sock; struct ifreq req; struct ipsectunnelconf *itc = (struct ipsectunnelconf*)&req.ifr_data; short phys_flags; int mtu; DBG2(DBG_KNL, "attaching virtual interface %s to %s", name, phys_name); if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) <= 0) { return FAILED; } strncpy(req.ifr_name, phys_name, IFNAMSIZ); if (ioctl(sock, SIOCGIFFLAGS, &req) < 0) { close(sock); return FAILED; } phys_flags = req.ifr_flags; strncpy(req.ifr_name, name, IFNAMSIZ); if (ioctl(sock, SIOCGIFFLAGS, &req) < 0) { close(sock); return FAILED; } if (req.ifr_flags & IFF_UP) { /* if it's already up, it is already attached, detach it first */ ioctl(sock, IPSEC_DEL_DEV, &req); } /* attach it */ strncpy(req.ifr_name, name, IFNAMSIZ); strncpy(itc->cf_name, phys_name, sizeof(itc->cf_name)); ioctl(sock, IPSEC_SET_DEV, &req); /* copy address from physical to virtual */ strncpy(req.ifr_name, phys_name, IFNAMSIZ); if (ioctl(sock, SIOCGIFADDR, &req) == 0) { strncpy(req.ifr_name, name, IFNAMSIZ); ioctl(sock, SIOCSIFADDR, &req); } /* copy net mask from physical to virtual */ strncpy(req.ifr_name, phys_name, IFNAMSIZ); if (ioctl(sock, SIOCGIFNETMASK, &req) == 0) { strncpy(req.ifr_name, name, IFNAMSIZ); ioctl(sock, SIOCSIFNETMASK, &req); } /* copy other flags and addresses */ strncpy(req.ifr_name, name, IFNAMSIZ); if (ioctl(sock, SIOCGIFFLAGS, &req) == 0) { if (phys_flags & IFF_POINTOPOINT) { req.ifr_flags |= IFF_POINTOPOINT; req.ifr_flags &= ~IFF_BROADCAST; ioctl(sock, SIOCSIFFLAGS, &req); strncpy(req.ifr_name, phys_name, IFNAMSIZ); if (ioctl(sock, SIOCGIFDSTADDR, &req) == 0) { strncpy(req.ifr_name, name, IFNAMSIZ); ioctl(sock, SIOCSIFDSTADDR, &req); } } else if (phys_flags & IFF_BROADCAST) { req.ifr_flags &= ~IFF_POINTOPOINT; req.ifr_flags |= IFF_BROADCAST; ioctl(sock, SIOCSIFFLAGS, &req); strncpy(req.ifr_name, phys_name, IFNAMSIZ); if (ioctl(sock, SIOCGIFBRDADDR, &req)==0) { strncpy(req.ifr_name, name, IFNAMSIZ); ioctl(sock, SIOCSIFBRDADDR, &req); } } else { req.ifr_flags &= ~IFF_POINTOPOINT; req.ifr_flags &= ~IFF_BROADCAST; ioctl(sock, SIOCSIFFLAGS, &req); } } mtu = lib->settings->get_int(lib->settings, "charon.plugins.kernel_klips.ipsec_dev_mtu", 0); if (mtu <= 0) { /* guess MTU as physical MTU - ESP overhead [- NAT-T overhead] * ESP overhead : 73 bytes * NAT-T overhead : 8 bytes ==> 81 bytes * * assuming tunnel mode with AES encryption and integrity * outer IP header : 20 bytes * (NAT-T UDP header: 8 bytes) * ESP header : 8 bytes * IV : 16 bytes * padding : 15 bytes (worst-case) * pad len / NH : 2 bytes * auth data : 12 bytes */ strncpy(req.ifr_name, phys_name, IFNAMSIZ); ioctl(sock, SIOCGIFMTU, &req); mtu = req.ifr_mtu - 81; } /* set MTU */ strncpy(req.ifr_name, name, IFNAMSIZ); req.ifr_mtu = mtu; ioctl(sock, SIOCSIFMTU, &req); /* bring ipsec device UP */ if (ioctl(sock, SIOCGIFFLAGS, &req) == 0) { req.ifr_flags |= IFF_UP; ioctl(sock, SIOCSIFFLAGS, &req); } close(sock); return SUCCESS; } /** * detach an ipsec device from a physical interface */ static status_t detach_ipsec_dev(char* name, char *phys_name) { int sock; struct ifreq req; DBG2(DBG_KNL, "detaching virtual interface %s from %s", name, strlen(phys_name) ? phys_name : "any physical interface"); if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) <= 0) { return FAILED; } strncpy(req.ifr_name, name, IFNAMSIZ); if (ioctl(sock, SIOCGIFFLAGS, &req) < 0) { close(sock); return FAILED; } /* shutting interface down */ if (req.ifr_flags & IFF_UP) { req.ifr_flags &= ~IFF_UP; ioctl(sock, SIOCSIFFLAGS, &req); } /* unset address */ memset(&req.ifr_addr, 0, sizeof(req.ifr_addr)); req.ifr_addr.sa_family = AF_INET; ioctl(sock, SIOCSIFADDR, &req); /* detach interface */ ioctl(sock, IPSEC_DEL_DEV, &req); close(sock); return SUCCESS; } /** * destroy an ipsec_dev_t object */ static void ipsec_dev_destroy(ipsec_dev_t *this) { detach_ipsec_dev(this->name, this->phys_name); free(this); } typedef struct route_entry_t route_entry_t; /** * installed routing entry */ struct route_entry_t { /** Name of the interface the route is bound to */ char *if_name; /** Source ip of the route */ host_t *src_ip; /** Gateway for this route */ host_t *gateway; /** Destination net */ chunk_t dst_net; /** Destination net prefixlen */ u_int8_t prefixlen; }; /** * destroy an route_entry_t object */ static void route_entry_destroy(route_entry_t *this) { free(this->if_name); this->src_ip->destroy(this->src_ip); this->gateway->destroy(this->gateway); chunk_free(&this->dst_net); free(this); } typedef struct policy_entry_t policy_entry_t; /** * installed kernel policy. */ struct policy_entry_t { /** reqid of this policy, if setup as trap */ u_int32_t reqid; /** direction of this policy: in, out, forward */ u_int8_t direction; /** parameters of installed policy */ struct { /** subnet and port */ host_t *net; /** subnet mask */ u_int8_t mask; /** protocol */ u_int8_t proto; } src, dst; /** associated route installed for this policy */ route_entry_t *route; /** by how many CHILD_SA's this policy is actively used */ u_int activecount; /** by how many CHILD_SA's this policy is trapped */ u_int trapcount; }; /** * convert a numerical netmask to a host_t */ static host_t *mask2host(int family, u_int8_t mask) { static const u_char bitmask[] = { 0x00, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe }; chunk_t chunk = chunk_alloca(family == AF_INET ? 4 : 16); int bytes = mask / 8, bits = mask % 8; memset(chunk.ptr, 0xFF, bytes); memset(chunk.ptr + bytes, 0, chunk.len - bytes); if (bits) { chunk.ptr[bytes] = bitmask[bits]; } return host_create_from_chunk(family, chunk, 0); } /** * check if a host is in a subnet (host with netmask in bits) */ static bool is_host_in_net(host_t *host, host_t *net, u_int8_t mask) { static const u_char bitmask[] = { 0x00, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe }; chunk_t host_chunk, net_chunk; int bytes = mask / 8, bits = mask % 8; host_chunk = host->get_address(host); net_chunk = net->get_address(net); if (host_chunk.len != net_chunk.len) { return FALSE; } if (memeq(host_chunk.ptr, net_chunk.ptr, bytes)) { return (bits == 0) || (host_chunk.ptr[bytes] & bitmask[bits]) == (net_chunk.ptr[bytes] & bitmask[bits]); } return FALSE; } /** * create a policy_entry_t object */ static policy_entry_t *create_policy_entry(traffic_selector_t *src_ts, traffic_selector_t *dst_ts, policy_dir_t dir) { policy_entry_t *policy = malloc_thing(policy_entry_t); policy->reqid = 0; policy->direction = dir; policy->route = NULL; policy->activecount = 0; policy->trapcount = 0; src_ts->to_subnet(src_ts, &policy->src.net, &policy->src.mask); dst_ts->to_subnet(dst_ts, &policy->dst.net, &policy->dst.mask); /* src or dest proto may be "any" (0), use more restrictive one */ policy->src.proto = max(src_ts->get_protocol(src_ts), dst_ts->get_protocol(dst_ts)); policy->src.proto = policy->src.proto ? policy->src.proto : 0; policy->dst.proto = policy->src.proto; return policy; } /** * destroy a policy_entry_t object */ static void policy_entry_destroy(policy_entry_t *this) { DESTROY_IF(this->src.net); DESTROY_IF(this->dst.net); if (this->route) { route_entry_destroy(this->route); } free(this); } /** * compares two policy_entry_t */ static inline bool policy_entry_equals(policy_entry_t *current, policy_entry_t *policy) { return current->direction == policy->direction && current->src.proto == policy->src.proto && current->dst.proto == policy->dst.proto && current->src.mask == policy->src.mask && current->dst.mask == policy->dst.mask && current->src.net->equals(current->src.net, policy->src.net) && current->dst.net->equals(current->dst.net, policy->dst.net); } static inline bool policy_entry_match_byaddrs(policy_entry_t *current, host_t *src, host_t *dst) { return is_host_in_net(src, current->src.net, current->src.mask) && is_host_in_net(dst, current->dst.net, current->dst.mask); } typedef struct sa_entry_t sa_entry_t; /** * used for two things: * - allocated SPIs that have not yet resulted in an installed SA * - installed inbound SAs with enabled UDP encapsulation */ struct sa_entry_t { /** protocol of this SA */ protocol_id_t protocol; /** reqid of this SA */ u_int32_t reqid; /** SPI of this SA */ u_int32_t spi; /** src address of this SA */ host_t *src; /** dst address of this SA */ host_t *dst; /** TRUE if this SA uses UDP encapsulation */ bool encap; /** TRUE if this SA is inbound */ bool inbound; }; /** * create an sa_entry_t object */ static sa_entry_t *create_sa_entry(protocol_id_t protocol, u_int32_t spi, u_int32_t reqid, host_t *src, host_t *dst, bool encap, bool inbound) { sa_entry_t *sa = malloc_thing(sa_entry_t); sa->protocol = protocol; sa->reqid = reqid; sa->spi = spi; sa->src = src ? src->clone(src) : NULL; sa->dst = dst ? dst->clone(dst) : NULL; sa->encap = encap; sa->inbound = inbound; return sa; } /** * destroy an sa_entry_t object */ static void sa_entry_destroy(sa_entry_t *this) { DESTROY_IF(this->src); DESTROY_IF(this->dst); free(this); } /** * match an sa_entry_t for an inbound SA that uses UDP encapsulation by spi and src (remote) address */ static inline bool sa_entry_match_encapbysrc(sa_entry_t *current, u_int32_t *spi, host_t *src) { return current->encap && current->inbound && current->spi == *spi && src->ip_equals(src, current->src); } /** * match an sa_entry_t by protocol, spi and dst address (as the kernel does it) */ static inline bool sa_entry_match_bydst(sa_entry_t *current, protocol_id_t *protocol, u_int32_t *spi, host_t *dst) { return current->protocol == *protocol && current->spi == *spi && dst->ip_equals(dst, current->dst); } /** * match an sa_entry_t by protocol, reqid and spi */ static inline bool sa_entry_match_byid(sa_entry_t *current, protocol_id_t *protocol, u_int32_t *spi, u_int32_t *reqid) { return current->protocol == *protocol && current->spi == *spi && current->reqid == *reqid; } typedef struct pfkey_msg_t pfkey_msg_t; struct pfkey_msg_t { /** * PF_KEY message base */ struct sadb_msg *msg; /** * PF_KEY message extensions */ union { struct sadb_ext *ext[SADB_EXT_MAX + 1]; struct { struct sadb_ext *reserved; /* SADB_EXT_RESERVED */ struct sadb_sa *sa; /* SADB_EXT_SA */ struct sadb_lifetime *lft_current; /* SADB_EXT_LIFETIME_CURRENT */ struct sadb_lifetime *lft_hard; /* SADB_EXT_LIFETIME_HARD */ struct sadb_lifetime *lft_soft; /* SADB_EXT_LIFETIME_SOFT */ struct sadb_address *src; /* SADB_EXT_ADDRESS_SRC */ struct sadb_address *dst; /* SADB_EXT_ADDRESS_DST */ struct sadb_address *proxy; /* SADB_EXT_ADDRESS_PROXY */ struct sadb_key *key_auth; /* SADB_EXT_KEY_AUTH */ struct sadb_key *key_encr; /* SADB_EXT_KEY_ENCRYPT */ struct sadb_ident *id_src; /* SADB_EXT_IDENTITY_SRC */ struct sadb_ident *id_dst; /* SADB_EXT_IDENTITY_DST */ struct sadb_sens *sensitivity; /* SADB_EXT_SENSITIVITY */ struct sadb_prop *proposal; /* SADB_EXT_PROPOSAL */ struct sadb_supported *supported_auth; /* SADB_EXT_SUPPORTED_AUTH */ struct sadb_supported *supported_encr; /* SADB_EXT_SUPPORTED_ENCRYPT */ struct sadb_spirange *spirange; /* SADB_EXT_SPIRANGE */ struct sadb_x_kmprivate *x_kmprivate; /* SADB_X_EXT_KMPRIVATE */ struct sadb_ext *x_policy; /* SADB_X_EXT_SATYPE2 */ struct sadb_ext *x_sa2; /* SADB_X_EXT_SA2 */ struct sadb_address *x_dst2; /* SADB_X_EXT_ADDRESS_DST2 */ struct sadb_address *x_src_flow; /* SADB_X_EXT_ADDRESS_SRC_FLOW */ struct sadb_address *x_dst_flow; /* SADB_X_EXT_ADDRESS_DST_FLOW */ struct sadb_address *x_src_mask; /* SADB_X_EXT_ADDRESS_SRC_MASK */ struct sadb_address *x_dst_mask; /* SADB_X_EXT_ADDRESS_DST_MASK */ struct sadb_x_debug *x_debug; /* SADB_X_EXT_DEBUG */ struct sadb_protocol *x_protocol; /* SADB_X_EXT_PROTOCOL */ struct sadb_x_nat_t_type *x_natt_type; /* SADB_X_EXT_NAT_T_TYPE */ struct sadb_x_nat_t_port *x_natt_sport; /* SADB_X_EXT_NAT_T_SPORT */ struct sadb_x_nat_t_port *x_natt_dport; /* SADB_X_EXT_NAT_T_DPORT */ struct sadb_address *x_natt_oa; /* SADB_X_EXT_NAT_T_OA */ } __attribute__((__packed__)); }; }; /** * convert a IKEv2 specific protocol identifier to the PF_KEY sa type */ static u_int8_t proto_ike2satype(protocol_id_t proto) { switch (proto) { case PROTO_ESP: return SADB_SATYPE_ESP; case PROTO_AH: return SADB_SATYPE_AH; case IPPROTO_COMP: return SADB_X_SATYPE_COMP; default: return proto; } } /** * convert a PF_KEY sa type to a IKEv2 specific protocol identifier */ static protocol_id_t proto_satype2ike(u_int8_t proto) { switch (proto) { case SADB_SATYPE_ESP: return PROTO_ESP; case SADB_SATYPE_AH: return PROTO_AH; case SADB_X_SATYPE_COMP: return IPPROTO_COMP; default: return proto; } } typedef struct kernel_algorithm_t kernel_algorithm_t; /** * Mapping of IKEv2 algorithms to PF_KEY algorithms */ struct kernel_algorithm_t { /** * Identifier specified in IKEv2 */ int ikev2; /** * Identifier as defined in pfkeyv2.h */ int kernel; }; #define END_OF_LIST -1 /** * Algorithms for encryption */ static kernel_algorithm_t encryption_algs[] = { /* {ENCR_DES_IV64, 0 }, */ {ENCR_DES, SADB_EALG_DESCBC }, {ENCR_3DES, SADB_EALG_3DESCBC }, /* {ENCR_RC5, 0 }, */ /* {ENCR_IDEA, 0 }, */ /* {ENCR_CAST, 0 }, */ {ENCR_BLOWFISH, SADB_EALG_BFCBC }, /* {ENCR_3IDEA, 0 }, */ /* {ENCR_DES_IV32, 0 }, */ {ENCR_NULL, SADB_EALG_NULL }, {ENCR_AES_CBC, SADB_EALG_AESCBC }, /* {ENCR_AES_CTR, 0 }, */ /* {ENCR_AES_CCM_ICV8, 0 }, */ /* {ENCR_AES_CCM_ICV12, 0 }, */ /* {ENCR_AES_CCM_ICV16, 0 }, */ /* {ENCR_AES_GCM_ICV8, 0 }, */ /* {ENCR_AES_GCM_ICV12, 0 }, */ /* {ENCR_AES_GCM_ICV16, 0 }, */ {END_OF_LIST, 0 }, }; /** * Algorithms for integrity protection */ static kernel_algorithm_t integrity_algs[] = { {AUTH_HMAC_MD5_96, SADB_AALG_MD5HMAC }, {AUTH_HMAC_SHA1_96, SADB_AALG_SHA1HMAC }, {AUTH_HMAC_SHA2_256_128, SADB_AALG_SHA256_HMAC }, {AUTH_HMAC_SHA2_384_192, SADB_AALG_SHA384_HMAC }, {AUTH_HMAC_SHA2_512_256, SADB_AALG_SHA512_HMAC }, /* {AUTH_DES_MAC, 0, }, */ /* {AUTH_KPDK_MD5, 0, }, */ /* {AUTH_AES_XCBC_96, 0, }, */ {END_OF_LIST, 0, }, }; #if 0 /** * Algorithms for IPComp, unused yet */ static kernel_algorithm_t compression_algs[] = { /* {IPCOMP_OUI, 0 }, */ {IPCOMP_DEFLATE, SADB_X_CALG_DEFLATE }, {IPCOMP_LZS, SADB_X_CALG_LZS }, /* {IPCOMP_LZJH, 0 }, */ {END_OF_LIST, 0 }, }; #endif /** * Look up a kernel algorithm ID and its key size */ static int lookup_algorithm(kernel_algorithm_t *list, int ikev2) { while (list->ikev2 != END_OF_LIST) { if (ikev2 == list->ikev2) { return list->kernel; } list++; } return 0; } /** * add a host behind a sadb_address extension */ static void host2ext(host_t *host, struct sadb_address *ext) { sockaddr_t *host_addr = host->get_sockaddr(host); socklen_t *len = host->get_sockaddr_len(host); memcpy((char*)(ext + 1), host_addr, *len); ext->sadb_address_len = PFKEY_LEN(sizeof(*ext) + *len); } /** * add a host to the given sadb_msg */ static void add_addr_ext(struct sadb_msg *msg, host_t *host, u_int16_t type) { struct sadb_address *addr = (struct sadb_address*)PFKEY_EXT_ADD_NEXT(msg); addr->sadb_address_exttype = type; host2ext(host, addr); PFKEY_EXT_ADD(msg, addr); } /** * adds an empty address extension to the given sadb_msg */ static void add_anyaddr_ext(struct sadb_msg *msg, int family, u_int8_t type) { socklen_t len = (family == AF_INET) ? sizeof(struct sockaddr_in) : sizeof(struct sockaddr_in6); struct sadb_address *addr = (struct sadb_address*)PFKEY_EXT_ADD_NEXT(msg); addr->sadb_address_exttype = type; sockaddr_t *saddr = (sockaddr_t*)(addr + 1); saddr->sa_family = family; addr->sadb_address_len = PFKEY_LEN(sizeof(*addr) + len); PFKEY_EXT_ADD(msg, addr); } /** * add udp encap extensions to a sadb_msg */ static void add_encap_ext(struct sadb_msg *msg, host_t *src, host_t *dst, bool ports_only) { struct sadb_x_nat_t_type* nat_type; struct sadb_x_nat_t_port* nat_port; if (!ports_only) { nat_type = (struct sadb_x_nat_t_type*)PFKEY_EXT_ADD_NEXT(msg); nat_type->sadb_x_nat_t_type_exttype = SADB_X_EXT_NAT_T_TYPE; nat_type->sadb_x_nat_t_type_len = PFKEY_LEN(sizeof(struct sadb_x_nat_t_type)); nat_type->sadb_x_nat_t_type_type = UDP_ENCAP_ESPINUDP; PFKEY_EXT_ADD(msg, nat_type); } nat_port = (struct sadb_x_nat_t_port*)PFKEY_EXT_ADD_NEXT(msg); nat_port->sadb_x_nat_t_port_exttype = SADB_X_EXT_NAT_T_SPORT; nat_port->sadb_x_nat_t_port_len = PFKEY_LEN(sizeof(struct sadb_x_nat_t_port)); nat_port->sadb_x_nat_t_port_port = src->get_port(src); PFKEY_EXT_ADD(msg, nat_port); nat_port = (struct sadb_x_nat_t_port*)PFKEY_EXT_ADD_NEXT(msg); nat_port->sadb_x_nat_t_port_exttype = SADB_X_EXT_NAT_T_DPORT; nat_port->sadb_x_nat_t_port_len = PFKEY_LEN(sizeof(struct sadb_x_nat_t_port)); nat_port->sadb_x_nat_t_port_port = dst->get_port(dst); PFKEY_EXT_ADD(msg, nat_port); } /** * build an SADB_X_ADDFLOW msg */ static void build_addflow(struct sadb_msg *msg, u_int8_t satype, u_int32_t spi, host_t *src, host_t *dst, host_t *src_net, u_int8_t src_mask, host_t *dst_net, u_int8_t dst_mask, u_int8_t protocol, bool replace) { struct sadb_sa *sa; struct sadb_protocol *proto; host_t *host; msg->sadb_msg_version = PF_KEY_V2; msg->sadb_msg_type = SADB_X_ADDFLOW; msg->sadb_msg_satype = satype; msg->sadb_msg_len = PFKEY_LEN(sizeof(struct sadb_msg)); sa = (struct sadb_sa*)PFKEY_EXT_ADD_NEXT(msg); sa->sadb_sa_exttype = SADB_EXT_SA; sa->sadb_sa_spi = spi; sa->sadb_sa_len = PFKEY_LEN(sizeof(struct sadb_sa)); sa->sadb_sa_flags = replace ? SADB_X_SAFLAGS_REPLACEFLOW : 0; PFKEY_EXT_ADD(msg, sa); if (!src) { add_anyaddr_ext(msg, src_net->get_family(src_net), SADB_EXT_ADDRESS_SRC); } else { add_addr_ext(msg, src, SADB_EXT_ADDRESS_SRC); } if (!dst) { add_anyaddr_ext(msg, dst_net->get_family(dst_net), SADB_EXT_ADDRESS_DST); } else { add_addr_ext(msg, dst, SADB_EXT_ADDRESS_DST); } add_addr_ext(msg, src_net, SADB_X_EXT_ADDRESS_SRC_FLOW); add_addr_ext(msg, dst_net, SADB_X_EXT_ADDRESS_DST_FLOW); host = mask2host(src_net->get_family(src_net), src_mask); add_addr_ext(msg, host, SADB_X_EXT_ADDRESS_SRC_MASK); host->destroy(host); host = mask2host(dst_net->get_family(dst_net), dst_mask); add_addr_ext(msg, host, SADB_X_EXT_ADDRESS_DST_MASK); host->destroy(host); proto = (struct sadb_protocol*)PFKEY_EXT_ADD_NEXT(msg); proto->sadb_protocol_exttype = SADB_X_EXT_PROTOCOL; proto->sadb_protocol_len = PFKEY_LEN(sizeof(struct sadb_protocol)); proto->sadb_protocol_proto = protocol; PFKEY_EXT_ADD(msg, proto); } /** * build an SADB_X_DELFLOW msg */ static void build_delflow(struct sadb_msg *msg, u_int8_t satype, host_t *src_net, u_int8_t src_mask, host_t *dst_net, u_int8_t dst_mask, u_int8_t protocol) { struct sadb_protocol *proto; host_t *host; msg->sadb_msg_version = PF_KEY_V2; msg->sadb_msg_type = SADB_X_DELFLOW; msg->sadb_msg_satype = satype; msg->sadb_msg_len = PFKEY_LEN(sizeof(struct sadb_msg)); add_addr_ext(msg, src_net, SADB_X_EXT_ADDRESS_SRC_FLOW); add_addr_ext(msg, dst_net, SADB_X_EXT_ADDRESS_DST_FLOW); host = mask2host(src_net->get_family(src_net), src_mask); add_addr_ext(msg, host, SADB_X_EXT_ADDRESS_SRC_MASK); host->destroy(host); host = mask2host(dst_net->get_family(dst_net), dst_mask); add_addr_ext(msg, host, SADB_X_EXT_ADDRESS_DST_MASK); host->destroy(host); proto = (struct sadb_protocol*)PFKEY_EXT_ADD_NEXT(msg); proto->sadb_protocol_exttype = SADB_X_EXT_PROTOCOL; proto->sadb_protocol_len = PFKEY_LEN(sizeof(struct sadb_protocol)); proto->sadb_protocol_proto = protocol; PFKEY_EXT_ADD(msg, proto); } /** * Parses a pfkey message received from the kernel */ static status_t parse_pfkey_message(struct sadb_msg *msg, pfkey_msg_t *out) { struct sadb_ext* ext; size_t len; memset(out, 0, sizeof(pfkey_msg_t)); out->msg = msg; len = msg->sadb_msg_len; len -= PFKEY_LEN(sizeof(struct sadb_msg)); ext = (struct sadb_ext*)(((char*)msg) + sizeof(struct sadb_msg)); while (len >= PFKEY_LEN(sizeof(struct sadb_ext))) { if (ext->sadb_ext_len < PFKEY_LEN(sizeof(struct sadb_ext)) || ext->sadb_ext_len > len) { DBG1(DBG_KNL, "length of PF_KEY extension (%d) is invalid", ext->sadb_ext_type); break; } if ((ext->sadb_ext_type > SADB_EXT_MAX) || (!ext->sadb_ext_type)) { DBG1(DBG_KNL, "type of PF_KEY extension (%d) is invalid", ext->sadb_ext_type); break; } if (out->ext[ext->sadb_ext_type]) { DBG1(DBG_KNL, "duplicate PF_KEY extension of type (%d)", ext->sadb_ext_type); break; } out->ext[ext->sadb_ext_type] = ext; ext = PFKEY_EXT_NEXT_LEN(ext, len); } if (len) { DBG1(DBG_KNL, "PF_KEY message length is invalid"); return FAILED; } return SUCCESS; } /** * Send a message to a specific PF_KEY socket and handle the response. */ static status_t pfkey_send_socket(private_kernel_klips_ipsec_t *this, int socket, struct sadb_msg *in, struct sadb_msg **out, size_t *out_len) { unsigned char buf[PFKEY_BUFFER_SIZE]; struct sadb_msg *msg; int in_len, len; this->mutex_pfkey->lock(this->mutex_pfkey); in->sadb_msg_seq = ++this->seq; in->sadb_msg_pid = getpid(); in_len = PFKEY_USER_LEN(in->sadb_msg_len); while (TRUE) { len = send(socket, in, in_len, 0); if (len != in_len) { switch (errno) { case EINTR: /* interrupted, try again */ continue; case EINVAL: case EEXIST: case ESRCH: /* we should also get a response for these from KLIPS */ break; default: this->mutex_pfkey->unlock(this->mutex_pfkey); DBG1(DBG_KNL, "error sending to PF_KEY socket: %s (%d)", strerror(errno), errno); return FAILED; } } break; } while (TRUE) { msg = (struct sadb_msg*)buf; len = recv(socket, buf, sizeof(buf), 0); if (len < 0) { if (errno == EINTR) { DBG1(DBG_KNL, "got interrupted"); /* interrupted, try again */ continue; } this->mutex_pfkey->unlock(this->mutex_pfkey); DBG1(DBG_KNL, "error reading from PF_KEY socket: %s", strerror(errno)); return FAILED; } if (len < sizeof(struct sadb_msg) || msg->sadb_msg_len < PFKEY_LEN(sizeof(struct sadb_msg))) { this->mutex_pfkey->unlock(this->mutex_pfkey); DBG1(DBG_KNL, "received corrupted PF_KEY message"); return FAILED; } if (msg->sadb_msg_len > len / PFKEY_ALIGNMENT) { this->mutex_pfkey->unlock(this->mutex_pfkey); DBG1(DBG_KNL, "buffer was too small to receive the complete PF_KEY message"); return FAILED; } if (msg->sadb_msg_pid != in->sadb_msg_pid) { DBG2(DBG_KNL, "received PF_KEY message is not intended for us"); continue; } if (msg->sadb_msg_seq != this->seq) { DBG1(DBG_KNL, "received PF_KEY message with invalid sequence number," " was %d expected %d", msg->sadb_msg_seq, this->seq); if (msg->sadb_msg_seq < this->seq) { continue; } this->mutex_pfkey->unlock(this->mutex_pfkey); return FAILED; } if (msg->sadb_msg_type != in->sadb_msg_type) { DBG2(DBG_KNL, "received PF_KEY message of wrong type," " was %d expected %d, ignoring", msg->sadb_msg_type, in->sadb_msg_type); } break; } *out_len = len; *out = (struct sadb_msg*)malloc(len); memcpy(*out, buf, len); this->mutex_pfkey->unlock(this->mutex_pfkey); return SUCCESS; } /** * Send a message to the default PF_KEY socket. */ static status_t pfkey_send(private_kernel_klips_ipsec_t *this, struct sadb_msg *in, struct sadb_msg **out, size_t *out_len) { return pfkey_send_socket(this, this->socket, in, out, out_len); } /** * Send a message to the default PF_KEY socket and handle the response. */ static status_t pfkey_send_ack(private_kernel_klips_ipsec_t *this, struct sadb_msg *in) { struct sadb_msg *out; size_t len; if (pfkey_send(this, in, &out, &len) != SUCCESS) { return FAILED; } else if (out->sadb_msg_errno) { DBG1(DBG_KNL, "PF_KEY error: %s (%d)", strerror(out->sadb_msg_errno), out->sadb_msg_errno); free(out); return FAILED; } free(out); return SUCCESS; } /** * Add an eroute to KLIPS */ static status_t add_eroute(private_kernel_klips_ipsec_t *this, u_int8_t satype, u_int32_t spi, host_t *src, host_t *dst, host_t *src_net, u_int8_t src_mask, host_t *dst_net, u_int8_t dst_mask, u_int8_t protocol, bool replace) { unsigned char request[PFKEY_BUFFER_SIZE]; struct sadb_msg *msg = (struct sadb_msg*)request; memset(&request, 0, sizeof(request)); build_addflow(msg, satype, spi, src, dst, src_net, src_mask, dst_net, dst_mask, protocol, replace); return pfkey_send_ack(this, msg); } /** * Delete an eroute fom KLIPS */ static status_t del_eroute(private_kernel_klips_ipsec_t *this, u_int8_t satype, host_t *src_net, u_int8_t src_mask, host_t *dst_net, u_int8_t dst_mask, u_int8_t protocol) { unsigned char request[PFKEY_BUFFER_SIZE]; struct sadb_msg *msg = (struct sadb_msg*)request; memset(&request, 0, sizeof(request)); build_delflow(msg, satype, src_net, src_mask, dst_net, dst_mask, protocol); return pfkey_send_ack(this, msg); } /** * Process a SADB_ACQUIRE message from the kernel */ static void process_acquire(private_kernel_klips_ipsec_t *this, struct sadb_msg* msg) { pfkey_msg_t response; host_t *src, *dst; u_int32_t reqid; u_int8_t proto; policy_entry_t *policy; job_t *job; switch (msg->sadb_msg_satype) { case SADB_SATYPE_UNSPEC: case SADB_SATYPE_ESP: case SADB_SATYPE_AH: break; default: /* acquire for AH/ESP only */ return; } if (parse_pfkey_message(msg, &response) != SUCCESS) { DBG1(DBG_KNL, "parsing SADB_ACQUIRE from kernel failed"); return; } /* KLIPS provides us only with the source and destination address, * and the transport protocol of the packet that triggered the policy. * we use this information to find a matching policy in our cache. * because KLIPS installs a narrow %hold eroute covering only this information, * we replace both the %trap and this %hold eroutes with a broader %hold * eroute covering the whole policy */ src = host_create_from_sockaddr((sockaddr_t*)(response.src + 1)); dst = host_create_from_sockaddr((sockaddr_t*)(response.dst + 1)); proto = response.src->sadb_address_proto; if (!src || !dst || src->get_family(src) != dst->get_family(dst)) { DBG1(DBG_KNL, "received an SADB_ACQUIRE with invalid hosts"); return; } DBG2(DBG_KNL, "received an SADB_ACQUIRE for %H == %H : %d", src, dst, proto); this->mutex->lock(this->mutex); if (this->policies->find_first(this->policies, (linked_list_match_t)policy_entry_match_byaddrs, (void**)&policy, src, dst) != SUCCESS) { this->mutex->unlock(this->mutex); DBG1(DBG_KNL, "received an SADB_ACQUIRE, but found no matching policy"); return; } if ((reqid = policy->reqid) == 0) { this->mutex->unlock(this->mutex); DBG1(DBG_KNL, "received an SADB_ACQUIRE, but policy is not routed anymore"); return; } /* add a broad %hold eroute that replaces the %trap eroute */ add_eroute(this, SADB_X_SATYPE_INT, htonl(SPI_HOLD), NULL, NULL, policy->src.net, policy->src.mask, policy->dst.net, policy->dst.mask, policy->src.proto, TRUE); /* remove the narrow %hold eroute installed by KLIPS */ del_eroute(this, SADB_X_SATYPE_INT, src, 32, dst, 32, proto); this->mutex->unlock(this->mutex); DBG2(DBG_KNL, "received an SADB_ACQUIRE"); DBG1(DBG_KNL, "creating acquire job for CHILD_SA with reqid {%d}", reqid); job = (job_t*)acquire_job_create(reqid, NULL, NULL); charon->processor->queue_job(charon->processor, job); } /** * Process a SADB_X_NAT_T_NEW_MAPPING message from the kernel */ static void process_mapping(private_kernel_klips_ipsec_t *this, struct sadb_msg* msg) { pfkey_msg_t response; u_int32_t spi, reqid; host_t *old_src, *new_src; job_t *job; DBG2(DBG_KNL, "received an SADB_X_NAT_T_NEW_MAPPING"); if (parse_pfkey_message(msg, &response) != SUCCESS) { DBG1(DBG_KNL, "parsing SADB_X_NAT_T_NEW_MAPPING from kernel failed"); return; } spi = response.sa->sadb_sa_spi; if (proto_satype2ike(msg->sadb_msg_satype) == PROTO_ESP) { sa_entry_t *sa; sockaddr_t *addr = (sockaddr_t*)(response.src + 1); old_src = host_create_from_sockaddr(addr); this->mutex->lock(this->mutex); if (!old_src || this->installed_sas->find_first(this->installed_sas, (linked_list_match_t)sa_entry_match_encapbysrc, (void**)&sa, &spi, old_src) != SUCCESS) { this->mutex->unlock(this->mutex); DBG1(DBG_KNL, "received an SADB_X_NAT_T_NEW_MAPPING, but found no matching SA"); return; } reqid = sa->reqid; this->mutex->unlock(this->mutex); addr = (sockaddr_t*)(response.dst + 1); switch (addr->sa_family) { case AF_INET: { struct sockaddr_in *sin = (struct sockaddr_in*)addr; sin->sin_port = htons(response.x_natt_dport->sadb_x_nat_t_port_port); } case AF_INET6: { struct sockaddr_in6 *sin6 = (struct sockaddr_in6*)addr; sin6->sin6_port = htons(response.x_natt_dport->sadb_x_nat_t_port_port); } default: break; } new_src = host_create_from_sockaddr(addr); if (new_src) { DBG1(DBG_KNL, "NAT mappings of ESP CHILD_SA with SPI %.8x and" " reqid {%d} changed, queuing update job", ntohl(spi), reqid); job = (job_t*)update_sa_job_create(reqid, new_src); charon->processor->queue_job(charon->processor, job); } } } /** * Receives events from kernel */ static job_requeue_t receive_events(private_kernel_klips_ipsec_t *this) { unsigned char buf[PFKEY_BUFFER_SIZE]; struct sadb_msg *msg = (struct sadb_msg*)buf; int len, oldstate; pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, &oldstate); len = recv(this->socket_events, buf, sizeof(buf), 0); pthread_setcancelstate(oldstate, NULL); if (len < 0) { switch (errno) { case EINTR: /* interrupted, try again */ return JOB_REQUEUE_DIRECT; case EAGAIN: /* no data ready, select again */ return JOB_REQUEUE_DIRECT; default: DBG1(DBG_KNL, "unable to receive from PF_KEY event socket"); sleep(1); return JOB_REQUEUE_FAIR; } } if (len < sizeof(struct sadb_msg) || msg->sadb_msg_len < PFKEY_LEN(sizeof(struct sadb_msg))) { DBG2(DBG_KNL, "received corrupted PF_KEY message"); return JOB_REQUEUE_DIRECT; } if (msg->sadb_msg_pid != 0) { /* not from kernel. not interested, try another one */ return JOB_REQUEUE_DIRECT; } if (msg->sadb_msg_len > len / PFKEY_ALIGNMENT) { DBG1(DBG_KNL, "buffer was too small to receive the complete PF_KEY message"); return JOB_REQUEUE_DIRECT; } switch (msg->sadb_msg_type) { case SADB_ACQUIRE: process_acquire(this, msg); break; case SADB_EXPIRE: /* SADB_EXPIRE events in KLIPS are only triggered by traffic (even for * the time based limits). So if there is no traffic for a longer * period than configured as hard limit, we wouldn't be able to rekey * the SA and just receive the hard expire and thus delete the SA. * To avoid this behavior and to make charon behave as with the other * kernel plugins, we implement the expiration of SAs ourselves. */ break; case SADB_X_NAT_T_NEW_MAPPING: process_mapping(this, msg); break; default: break; } return JOB_REQUEUE_DIRECT; } typedef enum { /** an SPI has expired */ EXPIRE_TYPE_SPI, /** a CHILD_SA has to be rekeyed */ EXPIRE_TYPE_SOFT, /** a CHILD_SA has to be deleted */ EXPIRE_TYPE_HARD } expire_type_t; typedef struct sa_expire_t sa_expire_t; struct sa_expire_t { /** kernel interface */ private_kernel_klips_ipsec_t *this; /** the SPI of the expiring SA */ u_int32_t spi; /** the protocol of the expiring SA */ protocol_id_t protocol; /** the reqid of the expiring SA*/ u_int32_t reqid; /** what type of expire this is */ expire_type_t type; }; /** * Called when an SA expires */ static job_requeue_t sa_expires(sa_expire_t *expire) { private_kernel_klips_ipsec_t *this = expire->this; protocol_id_t protocol = expire->protocol; u_int32_t spi = expire->spi, reqid = expire->reqid; bool hard = expire->type != EXPIRE_TYPE_SOFT; sa_entry_t *cached_sa; linked_list_t *list; job_t *job; /* for an expired SPI we first check whether the CHILD_SA got installed * in the meantime, for expired SAs we check whether they are still installed */ list = expire->type == EXPIRE_TYPE_SPI ? this->allocated_spis : this->installed_sas; this->mutex->lock(this->mutex); if (list->find_first(list, (linked_list_match_t)sa_entry_match_byid, (void**)&cached_sa, &protocol, &spi, &reqid) != SUCCESS) { /* we found no entry: * - for SPIs, a CHILD_SA has been installed * - for SAs, the CHILD_SA has already been deleted */ this->mutex->unlock(this->mutex); return JOB_REQUEUE_NONE; } else { list->remove(list, cached_sa, NULL); sa_entry_destroy(cached_sa); } this->mutex->unlock(this->mutex); DBG2(DBG_KNL, "%N CHILD_SA with SPI %.8x and reqid {%d} expired", protocol_id_names, protocol, ntohl(spi), reqid); DBG1(DBG_KNL, "creating %s job for %N CHILD_SA with SPI %.8x and reqid {%d}", hard ? "delete" : "rekey", protocol_id_names, protocol, ntohl(spi), reqid); if (hard) { job = (job_t*)delete_child_sa_job_create(reqid, protocol, spi); } else { job = (job_t*)rekey_child_sa_job_create(reqid, protocol, spi); } charon->processor->queue_job(charon->processor, job); return JOB_REQUEUE_NONE; } /** * Schedule an expire job for an SA. Time is in seconds. */ static void schedule_expire(private_kernel_klips_ipsec_t *this, protocol_id_t protocol, u_int32_t spi, u_int32_t reqid, expire_type_t type, u_int32_t time) { callback_job_t *job; sa_expire_t *expire = malloc_thing(sa_expire_t); expire->this = this; expire->protocol = protocol; expire->spi = spi; expire->reqid = reqid; expire->type = type; job = callback_job_create((callback_job_cb_t)sa_expires, expire, free, NULL); charon->scheduler->schedule_job(charon->scheduler, (job_t*)job, time * 1000); } /** * Implementation of kernel_interface_t.get_spi. */ static status_t get_spi(private_kernel_klips_ipsec_t *this, host_t *src, host_t *dst, protocol_id_t protocol, u_int32_t reqid, u_int32_t *spi) { /* we cannot use SADB_GETSPI because KLIPS does not allow us to set the * NAT-T type in an SADB_UPDATE which we would have to use to update the * implicitly created SA. */ rng_t *rng; u_int32_t spi_gen; rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK); if (!rng) { DBG1(DBG_KNL, "allocating SPI failed: no RNG"); return FAILED; } rng->get_bytes(rng, sizeof(spi_gen), (void*)&spi_gen); rng->destroy(rng); /* charon's SPIs lie within the range from 0xc0000000 to 0xcFFFFFFF */ spi_gen = 0xc0000000 | (spi_gen & 0x0FFFFFFF); DBG2(DBG_KNL, "allocated SPI %.8x for %N SA between %#H..%#H", spi_gen, protocol_id_names, protocol, src, dst); *spi = htonl(spi_gen); this->mutex->lock(this->mutex); this->allocated_spis->insert_last(this->allocated_spis, create_sa_entry(protocol, *spi, reqid, NULL, NULL, FALSE, TRUE)); this->mutex->unlock(this->mutex); schedule_expire(this, protocol, *spi, reqid, EXPIRE_TYPE_SPI, SPI_TIMEOUT); return SUCCESS; } /** * Implementation of kernel_interface_t.get_cpi. */ static status_t get_cpi(private_kernel_klips_ipsec_t *this, host_t *src, host_t *dst, u_int32_t reqid, u_int16_t *cpi) { return FAILED; } /** * Add a pseudo IPIP SA for tunnel mode with KLIPS. */ static status_t add_ipip_sa(private_kernel_klips_ipsec_t *this, host_t *src, host_t *dst, u_int32_t spi, u_int32_t reqid) { unsigned char request[PFKEY_BUFFER_SIZE]; struct sadb_msg *msg, *out; struct sadb_sa *sa; size_t len; memset(&request, 0, sizeof(request)); DBG2(DBG_KNL, "adding pseudo IPIP SA with SPI %.8x and reqid {%d}", ntohl(spi), reqid); msg = (struct sadb_msg*)request; msg->sadb_msg_version = PF_KEY_V2; msg->sadb_msg_type = SADB_ADD; msg->sadb_msg_satype = SADB_X_SATYPE_IPIP; msg->sadb_msg_len = PFKEY_LEN(sizeof(struct sadb_msg)); sa = (struct sadb_sa*)PFKEY_EXT_ADD_NEXT(msg); sa->sadb_sa_exttype = SADB_EXT_SA; sa->sadb_sa_len = PFKEY_LEN(sizeof(struct sadb_sa)); sa->sadb_sa_spi = spi; sa->sadb_sa_state = SADB_SASTATE_MATURE; PFKEY_EXT_ADD(msg, sa); add_addr_ext(msg, src, SADB_EXT_ADDRESS_SRC); add_addr_ext(msg, dst, SADB_EXT_ADDRESS_DST); if (pfkey_send(this, msg, &out, &len) != SUCCESS) { DBG1(DBG_KNL, "unable to add pseudo IPIP SA with SPI %.8x", ntohl(spi)); return FAILED; } else if (out->sadb_msg_errno) { DBG1(DBG_KNL, "unable to add pseudo IPIP SA with SPI %.8x: %s (%d)", ntohl(spi), strerror(out->sadb_msg_errno), out->sadb_msg_errno); free(out); return FAILED; } free(out); return SUCCESS; } /** * group the IPIP SA required for tunnel mode with the outer SA */ static status_t group_ipip_sa(private_kernel_klips_ipsec_t *this, host_t *src, host_t *dst, u_int32_t spi, protocol_id_t protocol, u_int32_t reqid) { unsigned char request[PFKEY_BUFFER_SIZE]; struct sadb_msg *msg, *out; struct sadb_sa *sa; struct sadb_x_satype *satype; size_t len; memset(&request, 0, sizeof(request)); DBG2(DBG_KNL, "grouping SAs with SPI %.8x and reqid {%d}", ntohl(spi), reqid); msg = (struct sadb_msg*)request; msg->sadb_msg_version = PF_KEY_V2; msg->sadb_msg_type = SADB_X_GRPSA; msg->sadb_msg_satype = SADB_X_SATYPE_IPIP; msg->sadb_msg_len = PFKEY_LEN(sizeof(struct sadb_msg)); sa = (struct sadb_sa*)PFKEY_EXT_ADD_NEXT(msg); sa->sadb_sa_exttype = SADB_EXT_SA; sa->sadb_sa_len = PFKEY_LEN(sizeof(struct sadb_sa)); sa->sadb_sa_spi = spi; sa->sadb_sa_state = SADB_SASTATE_MATURE; PFKEY_EXT_ADD(msg, sa); add_addr_ext(msg, dst, SADB_EXT_ADDRESS_DST); satype = (struct sadb_x_satype*)PFKEY_EXT_ADD_NEXT(msg); satype->sadb_x_satype_exttype = SADB_X_EXT_SATYPE2; satype->sadb_x_satype_len = PFKEY_LEN(sizeof(struct sadb_x_satype)); satype->sadb_x_satype_satype = proto_ike2satype(protocol); PFKEY_EXT_ADD(msg, satype); sa = (struct sadb_sa*)PFKEY_EXT_ADD_NEXT(msg); sa->sadb_sa_exttype = SADB_X_EXT_SA2; sa->sadb_sa_len = PFKEY_LEN(sizeof(struct sadb_sa)); sa->sadb_sa_spi = spi; sa->sadb_sa_state = SADB_SASTATE_MATURE; PFKEY_EXT_ADD(msg, sa); add_addr_ext(msg, dst, SADB_X_EXT_ADDRESS_DST2); if (pfkey_send(this, msg, &out, &len) != SUCCESS) { DBG1(DBG_KNL, "unable to group SAs with SPI %.8x", ntohl(spi)); return FAILED; } else if (out->sadb_msg_errno) { DBG1(DBG_KNL, "unable to group SAs with SPI %.8x: %s (%d)", ntohl(spi), strerror(out->sadb_msg_errno), out->sadb_msg_errno); free(out); return FAILED; } free(out); return SUCCESS; } /** * Implementation of kernel_interface_t.add_sa. */ static status_t add_sa(private_kernel_klips_ipsec_t *this, host_t *src, host_t *dst, u_int32_t spi, protocol_id_t protocol, u_int32_t reqid, u_int64_t expire_soft, u_int64_t expire_hard, u_int16_t enc_alg, chunk_t enc_key, u_int16_t int_alg, chunk_t int_key, ipsec_mode_t mode, u_int16_t ipcomp, u_int16_t cpi, bool encap, bool inbound) { unsigned char request[PFKEY_BUFFER_SIZE]; struct sadb_msg *msg, *out; struct sadb_sa *sa; struct sadb_key *key; size_t len; if (inbound) { /* for inbound SAs we allocated an SPI via get_spi, so we first check * whether that SPI has already expired (race condition) */ sa_entry_t *alloc_spi; this->mutex->lock(this->mutex); if (this->allocated_spis->find_first(this->allocated_spis, (linked_list_match_t)sa_entry_match_byid, (void**)&alloc_spi, &protocol, &spi, &reqid) != SUCCESS) { this->mutex->unlock(this->mutex); DBG1(DBG_KNL, "allocated SPI %.8x has already expired", ntohl(spi)); return FAILED; } else { this->allocated_spis->remove(this->allocated_spis, alloc_spi, NULL); sa_entry_destroy(alloc_spi); } this->mutex->unlock(this->mutex); } memset(&request, 0, sizeof(request)); DBG2(DBG_KNL, "adding SAD entry with SPI %.8x and reqid {%d}", ntohl(spi), reqid); msg = (struct sadb_msg*)request; msg->sadb_msg_version = PF_KEY_V2; msg->sadb_msg_type = SADB_ADD; msg->sadb_msg_satype = proto_ike2satype(protocol); msg->sadb_msg_len = PFKEY_LEN(sizeof(struct sadb_msg)); sa = (struct sadb_sa*)PFKEY_EXT_ADD_NEXT(msg); sa->sadb_sa_exttype = SADB_EXT_SA; sa->sadb_sa_len = PFKEY_LEN(sizeof(struct sadb_sa)); sa->sadb_sa_spi = spi; sa->sadb_sa_state = SADB_SASTATE_MATURE; sa->sadb_sa_replay = (protocol == IPPROTO_COMP) ? 0 : 32; sa->sadb_sa_auth = lookup_algorithm(integrity_algs, int_alg); sa->sadb_sa_encrypt = lookup_algorithm(encryption_algs, enc_alg); PFKEY_EXT_ADD(msg, sa); add_addr_ext(msg, src, SADB_EXT_ADDRESS_SRC); add_addr_ext(msg, dst, SADB_EXT_ADDRESS_DST); if (enc_alg != ENCR_UNDEFINED) { if (!sa->sadb_sa_encrypt) { DBG1(DBG_KNL, "algorithm %N not supported by kernel!", encryption_algorithm_names, enc_alg); return FAILED; } DBG2(DBG_KNL, " using encryption algorithm %N with key size %d", encryption_algorithm_names, enc_alg, enc_key.len * 8); key = (struct sadb_key*)PFKEY_EXT_ADD_NEXT(msg); key->sadb_key_exttype = SADB_EXT_KEY_ENCRYPT; key->sadb_key_bits = enc_key.len * 8; key->sadb_key_len = PFKEY_LEN(sizeof(struct sadb_key) + enc_key.len); memcpy(key + 1, enc_key.ptr, enc_key.len); PFKEY_EXT_ADD(msg, key); } if (int_alg != AUTH_UNDEFINED) { if (!sa->sadb_sa_auth) { DBG1(DBG_KNL, "algorithm %N not supported by kernel!", integrity_algorithm_names, int_alg); return FAILED; } DBG2(DBG_KNL, " using integrity algorithm %N with key size %d", integrity_algorithm_names, int_alg, int_key.len * 8); key = (struct sadb_key*)PFKEY_EXT_ADD_NEXT(msg); key->sadb_key_exttype = SADB_EXT_KEY_AUTH; key->sadb_key_bits = int_key.len * 8; key->sadb_key_len = PFKEY_LEN(sizeof(struct sadb_key) + int_key.len); memcpy(key + 1, int_key.ptr, int_key.len); PFKEY_EXT_ADD(msg, key); } if (ipcomp != IPCOMP_NONE) { /*TODO*/ } if (encap) { add_encap_ext(msg, src, dst, FALSE); } if (pfkey_send(this, msg, &out, &len) != SUCCESS) { DBG1(DBG_KNL, "unable to add SAD entry with SPI %.8x", ntohl(spi)); return FAILED; } else if (out->sadb_msg_errno) { DBG1(DBG_KNL, "unable to add SAD entry with SPI %.8x: %s (%d)", ntohl(spi), strerror(out->sadb_msg_errno), out->sadb_msg_errno); free(out); return FAILED; } free(out); /* for tunnel mode SAs we have to install an additional IPIP SA and * group the two SAs together */ if (mode == MODE_TUNNEL) { if (add_ipip_sa(this, src, dst, spi, reqid) != SUCCESS || group_ipip_sa(this, src, dst, spi, protocol, reqid) != SUCCESS) { DBG1(DBG_KNL, "unable to add SAD entry with SPI %.8x", ntohl(spi)); return FAILED; } } this->mutex->lock(this->mutex); /* we cache this SA for two reasons: * - in case an SADB_X_NAT_T_MAPPING_NEW event occurs (we need to find the reqid then) * - to decide if an expired SA is still installed */ this->installed_sas->insert_last(this->installed_sas, create_sa_entry(protocol, spi, reqid, src, dst, encap, inbound)); this->mutex->unlock(this->mutex); /* Although KLIPS supports SADB_EXT_LIFETIME_SOFT/HARD, we handle the lifetime * of SAs manually in the plugin. Refer to the comments in receive_events() * for details. */ if (expire_soft) { schedule_expire(this, protocol, spi, reqid, EXPIRE_TYPE_SOFT, expire_soft); } if (expire_hard) { schedule_expire(this, protocol, spi, reqid, EXPIRE_TYPE_HARD, expire_hard); } return SUCCESS; } /** * Implementation of kernel_interface_t.update_sa. */ static status_t update_sa(private_kernel_klips_ipsec_t *this, u_int32_t spi, protocol_id_t protocol, u_int16_t cpi, host_t *src, host_t *dst, host_t *new_src, host_t *new_dst, bool encap, bool new_encap) { unsigned char request[PFKEY_BUFFER_SIZE]; struct sadb_msg *msg, *out; struct sadb_sa *sa; size_t len; /* we can't update the SA if any of the ip addresses have changed. * that's because we can't use SADB_UPDATE and by deleting and readding the * SA the sequence numbers would get lost */ if (!src->ip_equals(src, new_src) || !dst->ip_equals(dst, new_dst)) { DBG1(DBG_KNL, "unable to update SAD entry with SPI %.8x: address changes" " are not supported", ntohl(spi)); return NOT_SUPPORTED; } /* because KLIPS does not allow us to change the NAT-T type in an SADB_UPDATE, * we can't update the SA if the encap flag has changed since installing it */ if (encap != new_encap) { DBG1(DBG_KNL, "unable to update SAD entry with SPI %.8x: change of UDP" " encapsulation is not supported", ntohl(spi)); return NOT_SUPPORTED; } DBG2(DBG_KNL, "updating SAD entry with SPI %.8x from %#H..%#H to %#H..%#H", ntohl(spi), src, dst, new_src, new_dst); memset(&request, 0, sizeof(request)); msg = (struct sadb_msg*)request; msg->sadb_msg_version = PF_KEY_V2; msg->sadb_msg_type = SADB_UPDATE; msg->sadb_msg_satype = proto_ike2satype(protocol); msg->sadb_msg_len = PFKEY_LEN(sizeof(struct sadb_msg)); sa = (struct sadb_sa*)PFKEY_EXT_ADD_NEXT(msg); sa->sadb_sa_exttype = SADB_EXT_SA; sa->sadb_sa_len = PFKEY_LEN(sizeof(struct sadb_sa)); sa->sadb_sa_spi = spi; sa->sadb_sa_encrypt = SADB_EALG_AESCBC; /* ignored */ sa->sadb_sa_auth = SADB_AALG_SHA1HMAC; /* ignored */ sa->sadb_sa_state = SADB_SASTATE_MATURE; PFKEY_EXT_ADD(msg, sa); add_addr_ext(msg, src, SADB_EXT_ADDRESS_SRC); add_addr_ext(msg, dst, SADB_EXT_ADDRESS_DST); add_encap_ext(msg, new_src, new_dst, TRUE); if (pfkey_send(this, msg, &out, &len) != SUCCESS) { DBG1(DBG_KNL, "unable to update SAD entry with SPI %.8x", ntohl(spi)); return FAILED; } else if (out->sadb_msg_errno) { DBG1(DBG_KNL, "unable to update SAD entry with SPI %.8x: %s (%d)", ntohl(spi), strerror(out->sadb_msg_errno), out->sadb_msg_errno); free(out); return FAILED; } free(out); return SUCCESS; } /** * Implementation of kernel_interface_t.del_sa. */ static status_t del_sa(private_kernel_klips_ipsec_t *this, host_t *dst, u_int32_t spi, protocol_id_t protocol, u_int16_t cpi) { unsigned char request[PFKEY_BUFFER_SIZE]; struct sadb_msg *msg, *out; struct sadb_sa *sa; sa_entry_t *cached_sa; size_t len; memset(&request, 0, sizeof(request)); /* all grouped SAs are automatically deleted by KLIPS as soon as * one of them is deleted, therefore we delete only the main one */ DBG2(DBG_KNL, "deleting SAD entry with SPI %.8x", ntohl(spi)); this->mutex->lock(this->mutex); /* this should not fail, but we don't care if it does, let the kernel decide * whether this SA exists or not */ if (this->installed_sas->find_first(this->installed_sas, (linked_list_match_t)sa_entry_match_bydst, (void**)&cached_sa, &protocol, &spi, dst) == SUCCESS) { this->installed_sas->remove(this->installed_sas, cached_sa, NULL); sa_entry_destroy(cached_sa); } this->mutex->unlock(this->mutex); msg = (struct sadb_msg*)request; msg->sadb_msg_version = PF_KEY_V2; msg->sadb_msg_type = SADB_DELETE; msg->sadb_msg_satype = proto_ike2satype(protocol); msg->sadb_msg_len = PFKEY_LEN(sizeof(struct sadb_msg)); sa = (struct sadb_sa*)PFKEY_EXT_ADD_NEXT(msg); sa->sadb_sa_exttype = SADB_EXT_SA; sa->sadb_sa_len = PFKEY_LEN(sizeof(struct sadb_sa)); sa->sadb_sa_spi = spi; PFKEY_EXT_ADD(msg, sa); /* the kernel wants an SADB_EXT_ADDRESS_SRC to be present even though * it is not used for anything. */ add_anyaddr_ext(msg, dst->get_family(dst), SADB_EXT_ADDRESS_SRC); add_addr_ext(msg, dst, SADB_EXT_ADDRESS_DST); if (pfkey_send(this, msg, &out, &len) != SUCCESS) { DBG1(DBG_KNL, "unable to delete SAD entry with SPI %.8x", ntohl(spi)); return FAILED; } else if (out->sadb_msg_errno) { DBG1(DBG_KNL, "unable to delete SAD entry with SPI %.8x: %s (%d)", ntohl(spi), strerror(out->sadb_msg_errno), out->sadb_msg_errno); free(out); return FAILED; } DBG2(DBG_KNL, "deleted SAD entry with SPI %.8x", ntohl(spi)); free(out); return SUCCESS; } /** * Implementation of kernel_interface_t.add_policy. */ static status_t add_policy(private_kernel_klips_ipsec_t *this, host_t *src, host_t *dst, traffic_selector_t *src_ts, traffic_selector_t *dst_ts, policy_dir_t direction, u_int32_t spi, protocol_id_t protocol, u_int32_t reqid, ipsec_mode_t mode, u_int16_t ipcomp, u_int16_t cpi, bool routed) { unsigned char request[PFKEY_BUFFER_SIZE]; struct sadb_msg *msg, *out; policy_entry_t *policy, *found = NULL; u_int8_t satype; size_t len; if (direction == POLICY_FWD) { /* no forward policies for KLIPS */ return SUCCESS; } /* tunnel mode policies direct the packets into the pseudo IPIP SA */ satype = (mode == MODE_TUNNEL) ? SADB_X_SATYPE_IPIP : proto_ike2satype(protocol); /* create a policy */ policy = create_policy_entry(src_ts, dst_ts, direction); /* find a matching policy */ this->mutex->lock(this->mutex); if (this->policies->find_first(this->policies, (linked_list_match_t)policy_entry_equals, (void**)&found, policy) == SUCCESS) { /* use existing policy */ DBG2(DBG_KNL, "policy %R === %R %N already exists, increasing" " refcount", src_ts, dst_ts, policy_dir_names, direction); policy_entry_destroy(policy); policy = found; } else { /* apply the new one, if we have no such policy */ this->policies->insert_last(this->policies, policy); } if (routed) { /* we install this as a %trap eroute in the kernel, later to be * triggered by packets matching the policy (-> ACQUIRE). */ spi = htonl(SPI_TRAP); satype = SADB_X_SATYPE_INT; /* the reqid is always set to the latest child SA that trapped this * policy. we will need this reqid upon receiving an acquire. */ policy->reqid = reqid; /* increase the trap counter */ policy->trapcount++; if (policy->activecount) { /* we do not replace the current policy in the kernel while a * policy is actively used */ this->mutex->unlock(this->mutex); return SUCCESS; } } else { /* increase the reference counter */ policy->activecount++; } DBG2(DBG_KNL, "adding policy %R === %R %N", src_ts, dst_ts, policy_dir_names, direction); memset(&request, 0, sizeof(request)); msg = (struct sadb_msg*)request; /* FIXME: SADB_X_SAFLAGS_INFLOW may be required, if we add an inbound policy for an IPIP SA */ build_addflow(msg, satype, spi, routed ? NULL : src, routed ? NULL : dst, policy->src.net, policy->src.mask, policy->dst.net, policy->dst.mask, policy->src.proto, found != NULL); this->mutex->unlock(this->mutex); if (pfkey_send(this, msg, &out, &len) != SUCCESS) { DBG1(DBG_KNL, "unable to add policy %R === %R %N", src_ts, dst_ts, policy_dir_names, direction); return FAILED; } else if (out->sadb_msg_errno) { DBG1(DBG_KNL, "unable to add policy %R === %R %N: %s (%d)", src_ts, dst_ts, policy_dir_names, direction, strerror(out->sadb_msg_errno), out->sadb_msg_errno); free(out); return FAILED; } free(out); this->mutex->lock(this->mutex); /* we try to find the policy again and install the route if needed */ if (this->policies->find_last(this->policies, NULL, (void**)&policy) != SUCCESS) { this->mutex->unlock(this->mutex); DBG2(DBG_KNL, "the policy %R === %R %N is already gone, ignoring", src_ts, dst_ts, policy_dir_names, direction); return SUCCESS; } /* KLIPS requires a special route that directs traffic that matches this * policy to one of the virtual ipsec interfaces. The virtual interface * has to be attached to the physical one the traffic runs over. * This is a special case of the source route we install in other kernel * interfaces. * In the following cases we do NOT install a source route (but just a * regular route): * - we are not in tunnel mode * - we are using IPv6 (does not work correctly yet!) * - routing is disabled via strongswan.conf */ if (policy->route == NULL && direction == POLICY_OUT) { char *iface; ipsec_dev_t *dev; route_entry_t *route = malloc_thing(route_entry_t); route->src_ip = NULL; if (mode != MODE_TRANSPORT && src->get_family(src) != AF_INET6 && this->install_routes) { charon->kernel_interface->get_address_by_ts(charon->kernel_interface, src_ts, &route->src_ip); } if (!route->src_ip) { route->src_ip = host_create_any(src->get_family(src)); } /* find the virtual interface */ iface = charon->kernel_interface->get_interface(charon->kernel_interface, src); if (find_ipsec_dev(this, iface, &dev) == SUCCESS) { /* above, we got either the name of a virtual or a physical * interface. for both cases it means we already have the devices * properly attached (assuming that we are exclusively attaching * ipsec devices). */ dev->refcount++; } else { /* there is no record of a mapping with the returned interface. * thus, we attach the first free virtual interface we find to * it. As above we assume we are the only client fiddling with * ipsec devices. */ if (this->ipsec_devices->find_first(this->ipsec_devices, (linked_list_match_t)ipsec_dev_match_free, (void**)&dev) == SUCCESS) { if (attach_ipsec_dev(dev->name, iface) == SUCCESS) { strncpy(dev->phys_name, iface, IFNAMSIZ); dev->refcount = 1; } else { DBG1(DBG_KNL, "failed to attach virtual interface %s" " to %s", dev->name, iface); this->mutex->unlock(this->mutex); free(iface); return FAILED; } } else { this->mutex->unlock(this->mutex); DBG1(DBG_KNL, "failed to attach a virtual interface to %s: no" " virtual interfaces left", iface); free(iface); return FAILED; } } free(iface); route->if_name = strdup(dev->name); /* get the nexthop to dst */ route->gateway = charon->kernel_interface->get_nexthop( charon->kernel_interface, dst); route->dst_net = chunk_clone(policy->dst.net->get_address(policy->dst.net)); route->prefixlen = policy->dst.mask; switch (charon->kernel_interface->add_route(charon->kernel_interface, route->dst_net, route->prefixlen, route->gateway, route->src_ip, route->if_name)) { default: DBG1(DBG_KNL, "unable to install route for policy %R === %R", src_ts, dst_ts); /* FALL */ case ALREADY_DONE: /* route exists, do not uninstall */ route_entry_destroy(route); break; case SUCCESS: /* cache the installed route */ policy->route = route; break; } } this->mutex->unlock(this->mutex); return SUCCESS; } /** * Implementation of kernel_interface_t.query_policy. */ static status_t query_policy(private_kernel_klips_ipsec_t *this, traffic_selector_t *src_ts, traffic_selector_t *dst_ts, policy_dir_t direction, u_int32_t *use_time) { #define IDLE_PREFIX "idle=" static const char *path_eroute = "/proc/net/ipsec_eroute"; static const char *path_spi = "/proc/net/ipsec_spi"; FILE *file; char line[1024], src[INET6_ADDRSTRLEN + 9], dst[INET6_ADDRSTRLEN + 9]; char *said = NULL, *pos; policy_entry_t *policy, *found = NULL; status_t status = FAILED; if (direction == POLICY_FWD) { /* we do not install forward policies */ return FAILED; } DBG2(DBG_KNL, "querying policy %R === %R %N", src_ts, dst_ts, policy_dir_names, direction); /* create a policy */ policy = create_policy_entry(src_ts, dst_ts, direction); /* find a matching policy */ this->mutex->lock(this->mutex); if (this->policies->find_first(this->policies, (linked_list_match_t)policy_entry_equals, (void**)&found, policy) != SUCCESS) { this->mutex->unlock(this->mutex); DBG1(DBG_KNL, "querying policy %R === %R %N failed, not found", src_ts, dst_ts, policy_dir_names, direction); policy_entry_destroy(policy); return NOT_FOUND; } policy_entry_destroy(policy); policy = found; /* src and dst selectors in KLIPS are of the form NET_ADDR/NETBITS:PROTO */ snprintf(src, sizeof(src), "%H/%d:%d", policy->src.net, policy->src.mask, policy->src.proto); src[sizeof(src) - 1] = '\0'; snprintf(dst, sizeof(dst), "%H/%d:%d", policy->dst.net, policy->dst.mask, policy->dst.proto); dst[sizeof(dst) - 1] = '\0'; this->mutex->unlock(this->mutex); /* we try to find the matching eroute first */ file = fopen(path_eroute, "r"); if (file == NULL) { DBG1(DBG_KNL, "unable to query policy %R === %R %N: %s (%d)", src_ts, dst_ts, policy_dir_names, direction, strerror(errno), errno); return FAILED; } /* read line by line where each line looks like: * packets src -> dst => said */ while (fgets(line, sizeof(line), file)) { enumerator_t *enumerator; char *token; int i = 0; enumerator = enumerator_create_token(line, " \t", " \t\n"); while (enumerator->enumerate(enumerator, &token)) { switch (i++) { case 0: /* packets */ continue; case 1: /* src */ if (streq(token, src)) { continue; } break; case 2: /* -> */ continue; case 3: /* dst */ if (streq(token, dst)) { continue; } break; case 4: /* => */ continue; case 5: /* said */ said = strdup(token); break; } break; } enumerator->destroy(enumerator); if (i == 5) { /* eroute matched */ break; } } fclose(file); if (said == NULL) { DBG1(DBG_KNL, "unable to query policy %R === %R %N: found no matching" " eroute", src_ts, dst_ts, policy_dir_names, direction); return FAILED; } /* compared with the one in the spi entry the SA ID from the eroute entry * has an additional ":PROTO" appended, which we need to cut off */ pos = strrchr(said, ':'); *pos = '\0'; /* now we try to find the matching spi entry */ file = fopen(path_spi, "r"); if (file == NULL) { DBG1(DBG_KNL, "unable to query policy %R === %R %N: %s (%d)", src_ts, dst_ts, policy_dir_names, direction, strerror(errno), errno); return FAILED; } while (fgets(line, sizeof(line), file)) { if (strneq(line, said, strlen(said))) { /* fine we found the correct line, now find the idle time */ u_int32_t idle_time; pos = strstr(line, IDLE_PREFIX); if (pos == NULL) { /* no idle time, i.e. this SA has not been used yet */ break; } if (sscanf(pos, IDLE_PREFIX"%u", &idle_time) <= 0) { /* idle time not valid */ break; } *use_time = time(NULL) - idle_time; status = SUCCESS; break; } } fclose(file); free(said); return status; } /** * Implementation of kernel_interface_t.del_policy. */ static status_t del_policy(private_kernel_klips_ipsec_t *this, traffic_selector_t *src_ts, traffic_selector_t *dst_ts, policy_dir_t direction, bool unrouted) { unsigned char request[PFKEY_BUFFER_SIZE]; struct sadb_msg *msg = (struct sadb_msg*)request, *out; policy_entry_t *policy, *found = NULL; route_entry_t *route; size_t len; if (direction == POLICY_FWD) { /* no forward policies for KLIPS */ return SUCCESS; } DBG2(DBG_KNL, "deleting policy %R === %R %N", src_ts, dst_ts, policy_dir_names, direction); /* create a policy */ policy = create_policy_entry(src_ts, dst_ts, direction); /* find a matching policy */ this->mutex->lock(this->mutex); if (this->policies->find_first(this->policies, (linked_list_match_t)policy_entry_equals, (void**)&found, policy) != SUCCESS) { this->mutex->unlock(this->mutex); DBG1(DBG_KNL, "deleting policy %R === %R %N failed, not found", src_ts, dst_ts, policy_dir_names, direction); policy_entry_destroy(policy); return NOT_FOUND; } policy_entry_destroy(policy); /* decrease appropriate counter */ unrouted ? found->trapcount-- : found->activecount--; if (found->trapcount == 0) { /* if this policy is finally unrouted, we reset the reqid because it * may still be actively used and there might be a pending acquire for * this policy. */ found->reqid = 0; } if (found->activecount > 0) { /* is still used by SAs, keep in kernel */ this->mutex->unlock(this->mutex); DBG2(DBG_KNL, "policy still used by another CHILD_SA, not removed"); return SUCCESS; } else if (found->activecount == 0 && found->trapcount > 0) { /* for a policy that is not used actively anymore, but is still trapped * by another child SA we replace the current eroute with a %trap eroute */ DBG2(DBG_KNL, "policy still routed by another CHILD_SA, not removed"); memset(&request, 0, sizeof(request)); build_addflow(msg, SADB_X_SATYPE_INT, htonl(SPI_TRAP), NULL, NULL, found->src.net, found->src.mask, found->dst.net, found->dst.mask, found->src.proto, TRUE); this->mutex->unlock(this->mutex); return pfkey_send_ack(this, msg); } /* remove if last reference */ this->policies->remove(this->policies, found, NULL); policy = found; this->mutex->unlock(this->mutex); memset(&request, 0, sizeof(request)); build_delflow(msg, 0, policy->src.net, policy->src.mask, policy->dst.net, policy->dst.mask, policy->src.proto); route = policy->route; policy->route = NULL; policy_entry_destroy(policy); if (pfkey_send(this, msg, &out, &len) != SUCCESS) { DBG1(DBG_KNL, "unable to delete policy %R === %R %N", src_ts, dst_ts, policy_dir_names, direction); return FAILED; } else if (out->sadb_msg_errno) { DBG1(DBG_KNL, "unable to delete policy %R === %R %N: %s (%d)", src_ts, dst_ts, policy_dir_names, direction, strerror(out->sadb_msg_errno), out->sadb_msg_errno); free(out); return FAILED; } free(out); if (route) { ipsec_dev_t *dev; if (charon->kernel_interface->del_route(charon->kernel_interface, route->dst_net, route->prefixlen, route->gateway, route->src_ip, route->if_name) != SUCCESS) { DBG1(DBG_KNL, "error uninstalling route installed with" " policy %R === %R %N", src_ts, dst_ts, policy_dir_names, direction); } /* we have to detach the ipsec interface from the physical one over which * this SA ran (if it is not used by any other) */ this->mutex->lock(this->mutex); if (find_ipsec_dev(this, route->if_name, &dev) == SUCCESS) { /* fine, we found a matching device object, let's check if we have * to detach it. */ if (--dev->refcount == 0) { if (detach_ipsec_dev(dev->name, dev->phys_name) != SUCCESS) { DBG1(DBG_KNL, "failed to detach virtual interface %s" " from %s", dev->name, dev->phys_name); } dev->phys_name[0] = '\0'; } } this->mutex->unlock(this->mutex); route_entry_destroy(route); } return SUCCESS; } /** * Initialize the list of ipsec devices */ static void init_ipsec_devices(private_kernel_klips_ipsec_t *this) { int i, count = lib->settings->get_int(lib->settings, "charon.plugins.kernel_klips.ipsec_dev_count", DEFAULT_IPSEC_DEV_COUNT); for (i = 0; i < count; ++i) { ipsec_dev_t *dev = malloc_thing(ipsec_dev_t); snprintf(dev->name, IFNAMSIZ, IPSEC_DEV_PREFIX"%d", i); dev->name[IFNAMSIZ - 1] = '\0'; dev->phys_name[0] = '\0'; dev->refcount = 0; this->ipsec_devices->insert_last(this->ipsec_devices, dev); /* detach any previously attached ipsec device */ detach_ipsec_dev(dev->name, dev->phys_name); } } /** * Register a socket for AQUIRE/EXPIRE messages */ static status_t register_pfkey_socket(private_kernel_klips_ipsec_t *this, u_int8_t satype) { unsigned char request[PFKEY_BUFFER_SIZE]; struct sadb_msg *msg, *out; size_t len; memset(&request, 0, sizeof(request)); msg = (struct sadb_msg*)request; msg->sadb_msg_version = PF_KEY_V2; msg->sadb_msg_type = SADB_REGISTER; msg->sadb_msg_satype = satype; msg->sadb_msg_len = PFKEY_LEN(sizeof(struct sadb_msg)); if (pfkey_send_socket(this, this->socket_events, msg, &out, &len) != SUCCESS) { DBG1(DBG_KNL, "unable to register PF_KEY socket"); return FAILED; } else if (out->sadb_msg_errno) { DBG1(DBG_KNL, "unable to register PF_KEY socket: %s (%d)", strerror(out->sadb_msg_errno), out->sadb_msg_errno); free(out); return FAILED; } free(out); return SUCCESS; } /** * Implementation of kernel_interface_t.destroy. */ static void destroy(private_kernel_klips_ipsec_t *this) { this->job->cancel(this->job); close(this->socket); close(this->socket_events); this->mutex_pfkey->destroy(this->mutex_pfkey); this->mutex->destroy(this->mutex); this->ipsec_devices->destroy_function(this->ipsec_devices, (void*)ipsec_dev_destroy); this->installed_sas->destroy_function(this->installed_sas, (void*)sa_entry_destroy); this->allocated_spis->destroy_function(this->allocated_spis, (void*)sa_entry_destroy); this->policies->destroy_function(this->policies, (void*)policy_entry_destroy); free(this); } /* * Described in header. */ kernel_klips_ipsec_t *kernel_klips_ipsec_create() { private_kernel_klips_ipsec_t *this = malloc_thing(private_kernel_klips_ipsec_t); /* public functions */ this->public.interface.get_spi = (status_t(*)(kernel_ipsec_t*,host_t*,host_t*,protocol_id_t,u_int32_t,u_int32_t*))get_spi; this->public.interface.get_cpi = (status_t(*)(kernel_ipsec_t*,host_t*,host_t*,u_int32_t,u_int16_t*))get_cpi; this->public.interface.add_sa = (status_t(*)(kernel_ipsec_t *,host_t*,host_t*,u_int32_t,protocol_id_t,u_int32_t,u_int64_t,u_int64_t,u_int16_t,chunk_t,u_int16_t,chunk_t,ipsec_mode_t,u_int16_t,u_int16_t,bool,bool))add_sa; this->public.interface.update_sa = (status_t(*)(kernel_ipsec_t*,u_int32_t,protocol_id_t,u_int16_t,host_t*,host_t*,host_t*,host_t*,bool,bool))update_sa; this->public.interface.del_sa = (status_t(*)(kernel_ipsec_t*,host_t*,u_int32_t,protocol_id_t,u_int16_t))del_sa; this->public.interface.add_policy = (status_t(*)(kernel_ipsec_t*,host_t*,host_t*,traffic_selector_t*,traffic_selector_t*,policy_dir_t,u_int32_t,protocol_id_t,u_int32_t,ipsec_mode_t,u_int16_t,u_int16_t,bool))add_policy; this->public.interface.query_policy = (status_t(*)(kernel_ipsec_t*,traffic_selector_t*,traffic_selector_t*,policy_dir_t,u_int32_t*))query_policy; this->public.interface.del_policy = (status_t(*)(kernel_ipsec_t*,traffic_selector_t*,traffic_selector_t*,policy_dir_t,bool))del_policy; this->public.interface.destroy = (void(*)(kernel_ipsec_t*)) destroy; /* private members */ this->policies = linked_list_create(); this->allocated_spis = linked_list_create(); this->installed_sas = linked_list_create(); this->ipsec_devices = linked_list_create(); this->mutex = mutex_create(MUTEX_DEFAULT); this->mutex_pfkey = mutex_create(MUTEX_DEFAULT); this->install_routes = lib->settings->get_bool(lib->settings, "charon.install_routes", TRUE); this->seq = 0; /* initialize ipsec devices */ init_ipsec_devices(this); /* create a PF_KEY socket to communicate with the kernel */ this->socket = socket(PF_KEY, SOCK_RAW, PF_KEY_V2); if (this->socket <= 0) { charon->kill(charon, "unable to create PF_KEY socket"); } /* create a PF_KEY socket for ACQUIRE & EXPIRE */ this->socket_events = socket(PF_KEY, SOCK_RAW, PF_KEY_V2); if (this->socket_events <= 0) { charon->kill(charon, "unable to create PF_KEY event socket"); } /* register the event socket */ if (register_pfkey_socket(this, SADB_SATYPE_ESP) != SUCCESS || register_pfkey_socket(this, SADB_SATYPE_AH) != SUCCESS) { charon->kill(charon, "unable to register PF_KEY event socket"); } this->job = callback_job_create((callback_job_cb_t)receive_events, this, NULL, NULL); charon->processor->queue_job(charon->processor, (job_t*)this->job); return &this->public; }