diff options
| -rw-r--r-- | accel-pppd/ctrl/ipoe/dhcpv4.c | 132 |
1 files changed, 76 insertions, 56 deletions
diff --git a/accel-pppd/ctrl/ipoe/dhcpv4.c b/accel-pppd/ctrl/ipoe/dhcpv4.c index 9427e142..76ad7c2b 100644 --- a/accel-pppd/ctrl/ipoe/dhcpv4.c +++ b/accel-pppd/ctrl/ipoe/dhcpv4.c @@ -29,6 +29,10 @@ #define BUF_SIZE 4096 +#ifndef max +#define max(x,y) ((x) > (y) ? (x) : (y)) +#endif + struct dhcpv4_relay_ctx { struct list_head entry; struct triton_context_t *ctx; @@ -556,18 +560,24 @@ static int dhcpv4_relay_read(struct triton_md_handler_t *h) } } - -uint16_t ip_csum(uint16_t *buf, int len) +static uint16_t ip_csum(uint16_t *buf, int len) { - uint32_t sum=0; - int i; + uint32_t sum = 0; - for (i=0; i < len; i += 2) + for (; len > 1; len -= 2) sum += *buf++; + if (len & 1) { +#ifdef __LITTLE_ENDIAN + sum += *(uint8_t *)buf; +#else + sum += *(uint8_t *)buf << 8; +#endif + } + // take only 16 bits out of the 32 bit sum and add up the carries while (sum >> 16) - sum = (sum & 0xffff) + (sum >> 16); + sum = (sum & 0xffff) + (sum >> 16); // one's complement the result sum = ~sum; @@ -575,62 +585,54 @@ uint16_t ip_csum(uint16_t *buf, int len) return sum & 0xffff; } - static int dhcpv4_send_raw(struct dhcpv4_serv *serv, struct dhcpv4_packet *pack, in_addr_t saddr, in_addr_t daddr, int dport) { - uint8_t hdr[sizeof(struct ether_header) + sizeof(struct iphdr) + sizeof(struct udphdr)]; - struct ether_header *eth = (struct ether_header *)hdr; - struct iphdr *ip = (struct iphdr *)(eth + 1); - struct udphdr *udp = (struct udphdr *)(ip + 1); - int len = pack->ptr - pack->data; - struct iovec iov[2]; - static uint8_t bc_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; + static const uint8_t bc_addr[ETH_ALEN] = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}; + struct { + struct ether_header eth; + struct iphdr ip; + struct udphdr udp; + uint8_t data[0]; + } __packed *hdr; struct sockaddr_ll ll_addr; - struct msghdr msg; + int n, len = pack->ptr - pack->data; memset(&ll_addr, 0, sizeof(ll_addr)); ll_addr.sll_family = AF_PACKET; ll_addr.sll_ifindex = serv->ifindex; ll_addr.sll_protocol = ntohs(ETH_P_IP); - msg.msg_name = &ll_addr; - msg.msg_namelen = sizeof(ll_addr); - msg.msg_iov = iov; - msg.msg_iovlen = 2; - msg.msg_controllen = 0; - msg.msg_flags = 0; - - memcpy(eth->ether_dhost, (pack->hdr->flags & DHCP_F_BROADCAST) ? bc_addr : pack->hdr->chaddr, ETH_ALEN); - memcpy(eth->ether_shost, serv->hwaddr, ETH_ALEN); - eth->ether_type = htons(ETH_P_IP); - - ip->ihl = 5; - ip->version = 4; - ip->tos = 0x10; - ip->tot_len = ntohs(sizeof(*ip) + sizeof(*udp) + len); - ip->id = 0; - ip->frag_off = 0; - ip->ttl = 128; - ip->protocol = IPPROTO_UDP; - ip->check = 0; - ip->saddr = saddr; - ip->daddr = (pack->hdr->flags & DHCP_F_BROADCAST) ? INADDR_BROADCAST : daddr; - barrier(); - ip->check = ip_csum((uint16_t *)ip, 20); - - udp->source = ntohs(DHCP_SERV_PORT); - udp->dest = ntohs(dport); - udp->len = htons(sizeof(*udp) + len); - udp->check = 0; - - iov[0].iov_base = hdr; - iov[0].iov_len = sizeof(hdr); - iov[1].iov_base = pack->data; - iov[1].iov_len = len; - - len = sendmsg(raw_sock, &msg, 0); - - if (len < 0) + hdr = alloca(sizeof(*hdr) + max(len, 300)); + memset(hdr, 0, sizeof(*hdr)); + memcpy(hdr->data, pack->data, len); + + // pad packet to minimal bootp length + if (len < 300) { + memset(hdr->data + len, 0, 300 - len); + len = 300; + } + + memcpy(hdr->eth.ether_dhost, (pack->hdr->flags & DHCP_F_BROADCAST) ? bc_addr : pack->hdr->chaddr, ETH_ALEN); + memcpy(hdr->eth.ether_shost, serv->hwaddr, ETH_ALEN); + hdr->eth.ether_type = htons(ETH_P_IP); + + hdr->ip.protocol = IPPROTO_UDP; + hdr->ip.saddr = saddr; + hdr->ip.daddr = (pack->hdr->flags & DHCP_F_BROADCAST) ? INADDR_BROADCAST : daddr; + hdr->udp.source = ntohs(DHCP_SERV_PORT); + hdr->udp.dest = ntohs(dport); + hdr->udp.len = hdr->ip.tot_len = htons(sizeof(hdr->udp) + len); + hdr->udp.check = ip_csum((uint16_t *)&hdr->ip, sizeof(hdr->ip) + sizeof(hdr->udp) + len); + + hdr->ip.ihl = sizeof(hdr->ip) >> 2; + hdr->ip.version = 4; + hdr->ip.tos = 0x10; + hdr->ip.ttl = 128; + hdr->ip.tot_len = ntohs(sizeof(hdr->ip) + sizeof(hdr->udp) + len); + hdr->ip.check = ip_csum((uint16_t *)&hdr->ip, sizeof(hdr->ip)); + + n = sendto(raw_sock, hdr, sizeof(*hdr) + len, 0, (struct sockaddr *)&ll_addr, sizeof(ll_addr)); + if (n != len) return -1; return 0; @@ -639,14 +641,19 @@ static int dhcpv4_send_raw(struct dhcpv4_serv *serv, struct dhcpv4_packet *pack, static int dhcpv4_send_udp(struct dhcpv4_serv *serv, struct dhcpv4_packet *pack, in_addr_t ip, int port) { struct sockaddr_in addr; - int n; - int len = pack->ptr - pack->data; + int n, len = pack->ptr - pack->data; memset(&addr, 0, sizeof(addr)); addr.sin_family = AF_INET; addr.sin_port = htons(port); addr.sin_addr.s_addr = ip; + // pad packet to minimal bootp length + if (len < 300) { + memset(pack->data + len, 0, 300 - len); + len = 300; + } + n = sendto(serv->hnd.fd, pack->data, len, 0, (struct sockaddr *)&addr, sizeof(addr)); if (n != len) return -1; @@ -1014,12 +1021,19 @@ int dhcpv4_relay_send(struct dhcpv4_relay *relay, struct dhcpv4_packet *request, } } + len = request->ptr - request->data; + + // pad packet to minimal bootp length + if (len < 300) { + memset(request->ptr, 0, 300 - len); + len = 300; + } + if (conf_verbose) { log_ppp_info2("send "); dhcpv4_print_packet(request, 1, log_ppp_info2); } - len = request->ptr - request->data; n = write(relay->hnd.fd, request->data, len); request->hdr->giaddr = giaddr; @@ -1077,6 +1091,12 @@ int dhcpv4_relay_send_release(struct dhcpv4_relay *relay, uint8_t *chaddr, uint3 len = pack->ptr - pack->data; + // pad packet to minimal bootp length + if (len < 300) { + memset(pack->ptr, 0, 300 - len); + len = 300; + } + if (conf_verbose) { log_ppp_info2("send "); dhcpv4_print_packet(pack, 1, log_ppp_info2); |