int ip_cmsg_send(struct net *net, struct msghdr *msg, struct ipcm_cookie *ipc) { int err; struct cmsghdr *cmsg; for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) { if (!CMSG_OK(msg, cmsg)) return -EINVAL; if (cmsg->cmsg_level != SOL_IP) continue; switch (cmsg->cmsg_type) { case IP_RETOPTS: err = cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr)); err = ip_options_get(net, &ipc->opt, CMSG_DATA(cmsg), err < 40 ? err : 40); if (err) return err; break; case IP_PKTINFO: { struct in_pktinfo *info; if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct in_pktinfo))) return -EINVAL; info = (struct in_pktinfo *)CMSG_DATA(cmsg); ipc->oif = info->ipi_ifindex; ipc->addr = info->ipi_spec_dst.s_addr; break; } default: return -EINVAL; } } return 0; }
int ip_cmsg_send(struct sock *sk, struct msghdr *msg, struct ipcm_cookie *ipc, bool allow_ipv6) { int err, val; struct cmsghdr *cmsg; struct net *net = sock_net(sk); for_each_cmsghdr(cmsg, msg) { if (!CMSG_OK(msg, cmsg)) return -EINVAL; #if IS_ENABLED(CONFIG_IPV6) if (allow_ipv6 && cmsg->cmsg_level == SOL_IPV6 && cmsg->cmsg_type == IPV6_PKTINFO) { struct in6_pktinfo *src_info; if (cmsg->cmsg_len < CMSG_LEN(sizeof(*src_info))) return -EINVAL; src_info = (struct in6_pktinfo *)CMSG_DATA(cmsg); if (!ipv6_addr_v4mapped(&src_info->ipi6_addr)) return -EINVAL; ipc->oif = src_info->ipi6_ifindex; ipc->addr = src_info->ipi6_addr.s6_addr32[3]; continue; } #endif if (cmsg->cmsg_level == SOL_SOCKET) { err = __sock_cmsg_send(sk, msg, cmsg, &ipc->sockc); if (err) return err; continue; } if (cmsg->cmsg_level != SOL_IP) continue; switch (cmsg->cmsg_type) { case IP_RETOPTS: err = cmsg->cmsg_len - sizeof(struct cmsghdr); /* Our caller is responsible for freeing ipc->opt */ err = ip_options_get(net, &ipc->opt, CMSG_DATA(cmsg), err < 40 ? err : 40); if (err) return err; break; case IP_PKTINFO: { struct in_pktinfo *info; if (cmsg->cmsg_len != CMSG_LEN(sizeof(struct in_pktinfo))) return -EINVAL; info = (struct in_pktinfo *)CMSG_DATA(cmsg); ipc->oif = info->ipi_ifindex; ipc->addr = info->ipi_spec_dst.s_addr; break; } case IP_TTL: if (cmsg->cmsg_len != CMSG_LEN(sizeof(int))) return -EINVAL; val = *(int *)CMSG_DATA(cmsg); if (val < 1 || val > 255) return -EINVAL; ipc->ttl = val; break; case IP_TOS: if (cmsg->cmsg_len == CMSG_LEN(sizeof(int))) val = *(int *)CMSG_DATA(cmsg); else if (cmsg->cmsg_len == CMSG_LEN(sizeof(u8))) val = *(u8 *)CMSG_DATA(cmsg); else return -EINVAL; if (val < 0 || val > 255) return -EINVAL; ipc->tos = val; ipc->priority = rt_tos2priority(ipc->tos); break; default: return -EINVAL; } } return 0; }