From 5e8f64f46cb1dd71b0a94cb7dad87da00b8c5e32 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Tue, 15 May 2012 01:51:29 +0200 Subject: conntrackd: add cthelper infrastructure (+ example FTP helper) This patch adds the user-space helper infrastructure. It also contains the implementation of the FTP helper in user-space. There's one example file that you can use to configure conntrackd as user-space connection tracking helper under: doc/helper/conntrackd.conf Signed-off-by: Pablo Neira Ayuso --- src/nfct-extensions/helper.c | 619 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 619 insertions(+) create mode 100644 src/nfct-extensions/helper.c (limited to 'src/nfct-extensions') diff --git a/src/nfct-extensions/helper.c b/src/nfct-extensions/helper.c new file mode 100644 index 0000000..e8f85bb --- /dev/null +++ b/src/nfct-extensions/helper.c @@ -0,0 +1,619 @@ +/* + * (C) 2012 by Pablo Neira Ayuso + * + * 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. + * + * This code has been sponsored by Vyatta Inc. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#include "nfct.h" +#include "helper.h" + +static void +nfct_cmd_helper_usage(char *argv[]) +{ + fprintf(stderr, "nfct v%s: Missing command\n" + "%s helper list|add|delete|get|flush " + "[parameters...]\n", VERSION, argv[0]); +} + +int +nfct_cmd_helper_parse_params(int argc, char *argv[]) +{ + int cmd = NFCT_CMD_NONE, ret = 0; + + if (argc < 3) { + fprintf(stderr, "nfct v%s: Missing command\n" + "%s helper list|add|delete|get|flush " + "[parameters...]\n", VERSION, argv[0]); + exit(EXIT_FAILURE); + } + if (strncmp(argv[2], "list", strlen(argv[2])) == 0) + cmd = NFCT_CMD_LIST; + else if (strncmp(argv[2], "add", strlen(argv[2])) == 0) + cmd = NFCT_CMD_ADD; + else if (strncmp(argv[2], "delete", strlen(argv[2])) == 0) + cmd = NFCT_CMD_DELETE; + else if (strncmp(argv[2], "get", strlen(argv[2])) == 0) + cmd = NFCT_CMD_GET; + else if (strncmp(argv[2], "flush", strlen(argv[2])) == 0) + cmd = NFCT_CMD_FLUSH; + else if (strncmp(argv[2], "disable", strlen(argv[2])) == 0) + cmd = NFCT_CMD_DISABLE; + else { + fprintf(stderr, "nfct v%s: Unknown command: %s\n", + VERSION, argv[2]); + nfct_cmd_helper_usage(argv); + exit(EXIT_FAILURE); + } + switch(cmd) { + case NFCT_CMD_LIST: + ret = nfct_cmd_helper_list(argc, argv); + break; + case NFCT_CMD_ADD: + ret = nfct_cmd_helper_add(argc, argv); + break; + case NFCT_CMD_DELETE: + ret = nfct_cmd_helper_delete(argc, argv); + break; + case NFCT_CMD_GET: + ret = nfct_cmd_helper_get(argc, argv); + break; + case NFCT_CMD_FLUSH: + ret = nfct_cmd_helper_flush(argc, argv); + break; + case NFCT_CMD_DISABLE: + ret = nfct_cmd_helper_disable(argc, argv); + break; + } + + return ret; +} + +static int nfct_helper_cb(const struct nlmsghdr *nlh, void *data) +{ + struct nfct_helper *t; + char buf[4096]; + + t = nfct_helper_alloc(); + if (t == NULL) { + nfct_perror("OOM"); + goto err; + } + + if (nfct_helper_nlmsg_parse_payload(nlh, t) < 0) { + nfct_perror("nfct_helper_nlmsg_parse_payload"); + goto err_free; + } + + nfct_helper_snprintf(buf, sizeof(buf), t, 0, 0); + printf("%s\n", buf); + +err_free: + nfct_helper_free(t); +err: + return MNL_CB_OK; +} + +int nfct_cmd_helper_list(int argc, char *argv[]) +{ + struct mnl_socket *nl; + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr *nlh; + unsigned int seq, portid; + int ret; + + if (argc > 3) { + nfct_perror("too many arguments"); + return -1; + } + + seq = time(NULL); + nlh = nfct_helper_nlmsg_build_hdr(buf, NFNL_MSG_CTHELPER_GET, + NLM_F_DUMP, seq); + + nl = mnl_socket_open(NETLINK_NETFILTER); + if (nl == NULL) { + nfct_perror("mnl_socket_open"); + return -1; + } + + if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) { + nfct_perror("mnl_socket_bind"); + return -1; + } + portid = mnl_socket_get_portid(nl); + + if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) { + nfct_perror("mnl_socket_send"); + return -1; + } + + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + while (ret > 0) { + ret = mnl_cb_run(buf, ret, seq, portid, nfct_helper_cb, NULL); + if (ret <= 0) + break; + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + } + if (ret == -1) { + nfct_perror("error"); + return -1; + } + mnl_socket_close(nl); + + return 0; +} + +int nfct_cmd_helper_add(int argc, char *argv[]) +{ + struct mnl_socket *nl; + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr *nlh; + uint32_t portid, seq; + struct nfct_helper *t; + uint16_t l3proto; + uint8_t l4proto; + struct ctd_helper *helper; + int ret, j; + + if (argc < 6) { + nfct_perror("missing parameters\n" + "syntax: nfct helper add name " + "family protocol"); + return -1; + } + + if (strcmp(argv[4], "inet") == 0) + l3proto = AF_INET; + else if (strcmp(argv[4], "inet6") == 0) + l3proto = AF_INET6; + else { + nfct_perror("unknown layer 3 protocol"); + return -1; + } + + if (strcmp(argv[5], "tcp") == 0) + l4proto = IPPROTO_TCP; + else if (strcmp(argv[5], "udp") == 0) + l4proto = IPPROTO_UDP; + else { + nfct_perror("unsupported layer 4 protocol"); + return -1; + } + + /* XXX use prefix defined in configure.ac. */ + helper = helper_find("/usr/lib/conntrack-tools", + argv[3], l4proto, RTLD_LAZY); + if (helper == NULL) { + nfct_perror("that helper is not supported"); + return -1; + } + + t = nfct_helper_alloc(); + if (t == NULL) { + nfct_perror("OOM"); + return -1; + } + nfct_helper_attr_set(t, NFCTH_ATTR_NAME, argv[3]); + nfct_helper_attr_set_u16(t, NFCTH_ATTR_PROTO_L3NUM, l3proto); + nfct_helper_attr_set_u8(t, NFCTH_ATTR_PROTO_L4NUM, l4proto); + nfct_helper_attr_set_u32(t, NFCTH_ATTR_PRIV_DATA_LEN, + helper->priv_data_len); + + for (j=0; jpolicy[j].name[0]) + break; + + p = nfct_helper_policy_alloc(); + if (p == NULL) { + nfct_perror("OOM"); + return -1; + } + + nfct_helper_policy_attr_set(p, NFCTH_ATTR_POLICY_NAME, + helper->policy[j].name); + nfct_helper_policy_attr_set_u32(p, NFCTH_ATTR_POLICY_TIMEOUT, + helper->policy[j].expect_timeout); + nfct_helper_policy_attr_set_u32(p, NFCTH_ATTR_POLICY_MAX, + helper->policy[j].expect_max); + + nfct_helper_attr_set(t, NFCTH_ATTR_POLICY+j, p); + } + + seq = time(NULL); + nlh = nfct_helper_nlmsg_build_hdr(buf, NFNL_MSG_CTHELPER_NEW, + NLM_F_CREATE | NLM_F_ACK, seq); + nfct_helper_nlmsg_build_payload(nlh, t); + + nfct_helper_free(t); + + nl = mnl_socket_open(NETLINK_NETFILTER); + if (nl == NULL) { + nfct_perror("mnl_socket_open"); + return -1; + } + + if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) { + nfct_perror("mnl_socket_bind"); + return -1; + } + portid = mnl_socket_get_portid(nl); + + if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) { + nfct_perror("mnl_socket_send"); + return -1; + } + + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + while (ret > 0) { + ret = mnl_cb_run(buf, ret, seq, portid, NULL, NULL); + if (ret <= 0) + break; + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + } + if (ret == -1) { + nfct_perror("error"); + return -1; + } + mnl_socket_close(nl); + + return 0; +} + +int nfct_cmd_helper_delete(int argc, char *argv[]) +{ + struct mnl_socket *nl; + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr *nlh; + uint32_t portid, seq; + struct nfct_helper *t; + int ret; + + if (argc < 4) { + nfct_perror("missing helper policy name"); + return -1; + } else if (argc > 6) { + nfct_perror("too many arguments"); + return -1; + } + + t = nfct_helper_alloc(); + if (t == NULL) { + nfct_perror("OOM"); + return -1; + } + + nfct_helper_attr_set(t, NFCTH_ATTR_NAME, argv[3]); + + if (argc >= 5) { + uint16_t l3proto; + + if (strcmp(argv[4], "inet") == 0) + l3proto = AF_INET; + else if (strcmp(argv[4], "inet6") == 0) + l3proto = AF_INET6; + else { + nfct_perror("unknown layer 3 protocol"); + return -1; + } + nfct_helper_attr_set_u16(t, NFCTH_ATTR_PROTO_L3NUM, l3proto); + } + + if (argc == 6) { + uint8_t l4proto; + + if (strcmp(argv[5], "tcp") == 0) + l4proto = IPPROTO_TCP; + else if (strcmp(argv[5], "udp") == 0) + l4proto = IPPROTO_UDP; + else { + nfct_perror("unsupported layer 4 protocol"); + return -1; + } + nfct_helper_attr_set_u32(t, NFCTH_ATTR_PROTO_L4NUM, l4proto); + } + + seq = time(NULL); + nlh = nfct_helper_nlmsg_build_hdr(buf, NFNL_MSG_CTHELPER_DEL, + NLM_F_ACK, seq); + nfct_helper_nlmsg_build_payload(nlh, t); + + nfct_helper_free(t); + + nl = mnl_socket_open(NETLINK_NETFILTER); + if (nl == NULL) { + nfct_perror("mnl_socket_open"); + return -1; + } + + if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) { + nfct_perror("mnl_socket_bind"); + return -1; + } + portid = mnl_socket_get_portid(nl); + + if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) { + nfct_perror("mnl_socket_send"); + return -1; + } + + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + while (ret > 0) { + ret = mnl_cb_run(buf, ret, seq, portid, NULL, NULL); + if (ret <= 0) + break; + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + } + if (ret == -1) { + nfct_perror("error"); + return -1; + } + + mnl_socket_close(nl); + + return 0; +} + +int nfct_cmd_helper_get(int argc, char *argv[]) +{ + struct mnl_socket *nl; + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr *nlh; + uint32_t portid, seq; + struct nfct_helper *t; + int ret; + + if (argc < 4) { + nfct_perror("missing helper policy name"); + return -1; + } else if (argc > 6) { + nfct_perror("too many arguments"); + return -1; + } + + t = nfct_helper_alloc(); + if (t == NULL) { + nfct_perror("OOM"); + return -1; + } + nfct_helper_attr_set(t, NFCTH_ATTR_NAME, argv[3]); + + if (argc >= 5) { + uint16_t l3proto; + + if (strcmp(argv[4], "inet") == 0) + l3proto = AF_INET; + else if (strcmp(argv[4], "inet6") == 0) + l3proto = AF_INET6; + else { + nfct_perror("unknown layer 3 protocol"); + return -1; + } + nfct_helper_attr_set_u16(t, NFCTH_ATTR_PROTO_L3NUM, l3proto); + } + + if (argc == 6) { + uint8_t l4proto; + + if (strcmp(argv[5], "tcp") == 0) + l4proto = IPPROTO_TCP; + else if (strcmp(argv[5], "udp") == 0) + l4proto = IPPROTO_UDP; + else { + nfct_perror("unsupported layer 4 protocol"); + return -1; + } + nfct_helper_attr_set_u32(t, NFCTH_ATTR_PROTO_L4NUM, l4proto); + } + + seq = time(NULL); + nlh = nfct_helper_nlmsg_build_hdr(buf, NFNL_MSG_CTHELPER_GET, + NLM_F_ACK, seq); + + nfct_helper_nlmsg_build_payload(nlh, t); + + nfct_helper_free(t); + + nl = mnl_socket_open(NETLINK_NETFILTER); + if (nl == NULL) { + nfct_perror("mnl_socket_open"); + return -1; + } + + if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) { + nfct_perror("mnl_socket_bind"); + return -1; + } + portid = mnl_socket_get_portid(nl); + + if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) { + nfct_perror("mnl_socket_send"); + return -1; + } + + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + while (ret > 0) { + ret = mnl_cb_run(buf, ret, seq, portid, nfct_helper_cb, NULL); + if (ret <= 0) + break; + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + } + if (ret == -1) { + nfct_perror("error"); + return -1; + } + mnl_socket_close(nl); + + return 0; +} + +int nfct_cmd_helper_flush(int argc, char *argv[]) +{ + struct mnl_socket *nl; + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr *nlh; + uint32_t portid, seq; + int ret; + + if (argc > 3) { + nfct_perror("too many arguments"); + return -1; + } + + seq = time(NULL); + nlh = nfct_helper_nlmsg_build_hdr(buf, NFNL_MSG_CTHELPER_DEL, + NLM_F_ACK, seq); + + nl = mnl_socket_open(NETLINK_NETFILTER); + if (nl == NULL) { + nfct_perror("mnl_socket_open"); + return -1; + } + + if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) { + nfct_perror("mnl_socket_bind"); + return -1; + } + portid = mnl_socket_get_portid(nl); + + if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) { + nfct_perror("mnl_socket_send"); + return -1; + } + + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + while (ret > 0) { + ret = mnl_cb_run(buf, ret, seq, portid, NULL, NULL); + if (ret <= 0) + break; + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + } + if (ret == -1) { + nfct_perror("error"); + return -1; + } + + mnl_socket_close(nl); + + return 0; +} + +int nfct_cmd_helper_disable(int argc, char *argv[]) +{ + struct mnl_socket *nl; + char buf[MNL_SOCKET_BUFFER_SIZE]; + struct nlmsghdr *nlh; + uint32_t portid, seq; + struct nfct_helper *t; + uint16_t l3proto; + uint8_t l4proto; + struct ctd_helper *helper; + int ret; + + if (argc < 6) { + nfct_perror("missing parameters\n" + "syntax: nfct helper add name " + "family protocol"); + return -1; + } + + if (strcmp(argv[4], "inet") == 0) + l3proto = AF_INET; + else if (strcmp(argv[4], "inet6") == 0) + l3proto = AF_INET6; + else { + nfct_perror("unknown layer 3 protocol"); + return -1; + } + + if (strcmp(argv[5], "tcp") == 0) + l4proto = IPPROTO_TCP; + else if (strcmp(argv[5], "udp") == 0) + l4proto = IPPROTO_UDP; + else { + nfct_perror("unsupported layer 4 protocol"); + return -1; + } + + /* XXX use prefix defined in configure.ac. */ + helper = helper_find("/usr/lib/conntrack-tools", + argv[3], l4proto, RTLD_LAZY); + if (helper == NULL) { + nfct_perror("that helper is not supported"); + return -1; + } + + t = nfct_helper_alloc(); + if (t == NULL) { + nfct_perror("OOM"); + return -1; + } + nfct_helper_attr_set(t, NFCTH_ATTR_NAME, argv[3]); + nfct_helper_attr_set_u16(t, NFCTH_ATTR_PROTO_L3NUM, l3proto); + nfct_helper_attr_set_u8(t, NFCTH_ATTR_PROTO_L4NUM, l4proto); + nfct_helper_attr_set_u32(t, NFCTH_ATTR_STATUS, + NFCT_HELPER_STATUS_DISABLED); + + seq = time(NULL); + nlh = nfct_helper_nlmsg_build_hdr(buf, NFNL_MSG_CTHELPER_NEW, + NLM_F_CREATE | NLM_F_ACK, seq); + nfct_helper_nlmsg_build_payload(nlh, t); + + nfct_helper_free(t); + + nl = mnl_socket_open(NETLINK_NETFILTER); + if (nl == NULL) { + nfct_perror("mnl_socket_open"); + return -1; + } + + if (mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID) < 0) { + nfct_perror("mnl_socket_bind"); + return -1; + } + portid = mnl_socket_get_portid(nl); + + if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) { + nfct_perror("mnl_socket_send"); + return -1; + } + + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + while (ret > 0) { + ret = mnl_cb_run(buf, ret, seq, portid, NULL, NULL); + if (ret <= 0) + break; + ret = mnl_socket_recvfrom(nl, buf, sizeof(buf)); + } + if (ret == -1) { + nfct_perror("error"); + return -1; + } + mnl_socket_close(nl); + + return 0; +} + -- cgit v1.2.3