6 #include <sys/socket.h>
8 #include "greprotocol.h"
13 uint8_t reserved0_hi : 4;
17 uint8_t has_checksum : 1;
20 uint8_t reserved0_lo: 5;
22 uint16_t protocol_type;
26 GREProtocol::GREProtocol(const in6_addr &src, const in6_addr &dst)
29 memset(&dstaddr, 0, sizeof(dstaddr));
30 dstaddr.sin6_family = AF_INET6;
31 dstaddr.sin6_addr = dst;
33 sock = socket(AF_INET6, SOCK_RAW, IPPROTO_GRE);
40 memset(&my_addr, 0, sizeof(my_addr));
41 my_addr.sin6_family = AF_INET6;
42 my_addr.sin6_addr = src;
43 if (::bind(sock, (sockaddr *)&my_addr, sizeof(my_addr)) == -1) {
49 void GREProtocol::send_packet(uint16_t proto, const string &data, int incoming_seq)
52 gre_header *gre = (gre_header *)buf;
54 memset(gre, 0, sizeof(*gre));
57 gre->protocol_type = htons(proto);
59 char *ptr = buf + sizeof(*gre);
60 int seq_be = htonl(seq++); // Ignore incoming_seq.
61 memcpy(ptr, &seq_be, sizeof(seq_be));
62 ptr += sizeof(seq_be);
64 memcpy(ptr, data.data(), data.size());
66 if (sendto(sock, buf, data.size() + sizeof(seq_be) + sizeof(*gre), 0, (sockaddr *)&dstaddr, sizeof(dstaddr)) == -1) {
72 int GREProtocol::fd() const
77 void GREProtocol::read_packet(Protocol *sender)
79 struct sockaddr_storage addr;
80 socklen_t addrlen = sizeof(addr);
82 int ret = recvfrom(sock, buf, sizeof(buf), 0, (struct sockaddr *)&addr, &addrlen);
87 if (addr.ss_family != AF_INET6) {
90 struct in6_addr *addr6 = &((struct sockaddr_in6 *)&addr)->sin6_addr;
91 if (memcmp(addr6, &dstaddr.sin6_addr, sizeof(*addr6)) != 0) {
95 gre_header* gre = (gre_header *)buf;
97 char* ptr = buf + sizeof(gre_header);
98 if (gre->has_checksum) {
106 seq = ntohl(*(uint32_t *)ptr);
110 //printf("gre packet: proto=%x\n", ntohs(gre->protocol_type));
112 sender->send_packet(ntohs(gre->protocol_type), string(ptr, buf + ret), seq);