3 #include <sys/socket.h>
5 #include "greprotocol.h"
11 uint8_t reserved0_hi : 4;
15 uint8_t has_checksum : 1;
18 uint8_t reserved0_lo: 5;
20 uint16_t protocol_type;
24 GREProtocol::GREProtocol(const in6_addr &src, const in6_addr &dst)
27 memset(&dstaddr, 0, sizeof(dstaddr));
28 dstaddr.sin6_family = AF_INET6;
29 dstaddr.sin6_addr = dst;
31 sock = socket(AF_INET6, SOCK_RAW, IPPROTO_GRE);
38 memset(&my_addr, 0, sizeof(my_addr));
39 my_addr.sin6_family = AF_INET6;
40 my_addr.sin6_addr = src;
41 if (::bind(sock, (sockaddr *)&my_addr, sizeof(my_addr)) == -1) {
47 void GREProtocol::send_packet(uint16_t proto, const string &data, int incoming_seq)
50 gre_header *gre = (gre_header *)buf;
52 memset(gre, 0, sizeof(*gre));
55 gre->protocol_type = htons(proto);
57 char *ptr = buf + sizeof(*gre);
58 int seq_be = htonl(seq++); // Ignore incoming_seq.
59 memcpy(ptr, &seq_be, sizeof(seq_be));
60 ptr += sizeof(seq_be);
62 memcpy(ptr, data.data(), data.size());
64 if (sendto(sock, buf, data.size() + sizeof(seq_be) + sizeof(*gre), 0, (sockaddr *)&dstaddr, sizeof(dstaddr)) == -1) {
70 int GREProtocol::fd() const
75 void GREProtocol::read_packet(Protocol *sender)
77 struct sockaddr_storage addr;
78 socklen_t addrlen = sizeof(addr);
80 int ret = recvfrom(sock, buf, sizeof(buf), 0, (struct sockaddr *)&addr, &addrlen);
85 if (addr.ss_family != AF_INET6) {
88 struct in6_addr *addr6 = &((struct sockaddr_in6 *)&addr)->sin6_addr;
89 if (memcmp(addr6, &dstaddr.sin6_addr, sizeof(*addr6)) != 0) {
93 gre_header* gre = (gre_header *)buf;
95 char* ptr = buf + sizeof(gre_header);
96 if (gre->has_checksum) {
104 seq = ntohl(*(uint32_t *)ptr);
108 //printf("gre packet: proto=%x\n", ntohs(gre->protocol_type));
110 sender->send_packet(ntohs(gre->protocol_type), string(ptr, buf + ret), seq);