int red_recv_udp_pkt(int fd, char *buf, size_t buflen, struct sockaddr_in *inaddr, struct sockaddr_in *toaddr)
{
socklen_t addrlen = sizeof(*inaddr);
ssize_t pktlen;
struct msghdr msg;
struct iovec io;
char control[1024];
memset(&msg, 0, sizeof(msg));
msg.msg_name = inaddr;
msg.msg_namelen = sizeof(*inaddr);
msg.msg_iov = &io;
msg.msg_iovlen = 1;
msg.msg_control = control;
msg.msg_controllen = sizeof(control);
io.iov_base = buf;
io.iov_len = buflen;
pktlen = recvmsg(fd, &msg, 0);
if (pktlen == -1) {
log_errno(LOG_WARNING, "recvfrom");
return -1;
}
if (toaddr) {
memset(toaddr, 0, sizeof(*toaddr));
for (struct cmsghdr* cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
if (
cmsg->cmsg_level == SOL_IP &&
cmsg->cmsg_type == IP_ORIGDSTADDR &&
cmsg->cmsg_len >= CMSG_LEN(sizeof(*toaddr))
) {
struct sockaddr_in* cmsgaddr = (struct sockaddr_in*)CMSG_DATA(cmsg);
memcpy(toaddr, cmsgaddr, sizeof(*toaddr));
}
else {
log_error(LOG_WARNING, "unexepcted cmsg (level,type) = (%d,%d)",
cmsg->cmsg_level, cmsg->cmsg_type);
}
}
if (toaddr->sin_family != AF_INET) {
log_error(LOG_WARNING, "(SOL_IP, IP_ORIGDSTADDR) not found");
return -1;
}
}
if (addrlen != sizeof(*inaddr)) {
log_error(LOG_WARNING, "unexpected address length %u instead of %zu", addrlen, sizeof(*inaddr));
return -1;
}
if (pktlen >= buflen) {
char buf[RED_INET_ADDRSTRLEN];
log_error(LOG_WARNING, "wow! Truncated udp packet of size %zd from %s! impossible! dropping it...",
pktlen, red_inet_ntop(inaddr, buf, sizeof(buf)));
return -1;
}
return pktlen;
}
static int ss_instance_init(struct redudp_instance_t *instance)
{
ss_instance * ss = (ss_instance *)(instance+1);
const redudp_config *config = &instance->config;
char buf1[RED_INET_ADDRSTRLEN];
int valid_cred = ss_is_valid_cred(config->login, config->password);
if (!valid_cred
|| (ss->method = enc_init(&ss->info, config->password, config->login), ss->method == -1))
{
log_error(LOG_ERR, "Invalided encrytion method or password.");
return -1;
}
else
{
log_error(LOG_INFO, "%s @ %s: encryption method: %s",
instance->relay_ss->name,
red_inet_ntop(&instance->config.bindaddr, buf1, sizeof(buf1)),
config->login);
}
// An additional buffer is allocated for each instance for encryption/decrption.
ss->buff = malloc(MAX_UDP_PACKET_SIZE);
if (!ss->buff) {
log_error(LOG_ERR, "Out of memory.");
return -1;
}
return 0;
}
