1 #include <linux/module.h>
2 #include <linux/version.h>
4 #include <net/protocol.h>
11 MODULE_DESCRIPTION("Multi-Party Transport Protocol");
12 MODULE_AUTHOR("Adrian Bondrescu/Cornel Mercan");
13 MODULE_LICENSE("GPL");
16 struct inet_sock sock;
17 /* mptp socket speciffic data */
22 static struct mptp_sock * sock_port_map[MAX_MPTP_PORT];
24 static inline struct mptp_sock * mptp_sk(struct sock * sock)
26 return (struct mptp_sock *)(sock);
29 static inline struct mptphdr * mptp_hdr(const struct sk_buff * skb)
31 return (struct mptphdr *) skb_transport_header(skb);
34 static inline uint8_t get_next_free_port(void)
37 for (i = MIN_MPTP_PORT; i < MAX_MPTP_PORT; i ++)
38 if (sock_port_map[i] == NULL)
43 static inline void mptp_unhash(uint8_t port)
45 sock_port_map[port] = NULL;
48 static inline void mptp_hash(uint8_t port, struct mptp_sock *ssh)
50 sock_port_map[port] = ssh;
53 static inline struct mptp_sock * mptp_lookup(uint8_t port)
55 return sock_port_map[port];
58 static int mptp_release(struct socket *sock)
60 struct sock *sk = sock->sk;
61 struct mptp_sock * ssk = mptp_sk(sk);
66 mptp_unhash(ssk->src);
68 sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
75 skb_queue_purge(&sk->sk_receive_queue);
77 log_debug("mptp_release sock=%p\n", sk);
83 static int mptp_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
85 struct sockaddr_mptp *mptp_addr;
86 struct mptp_sock *ssk;
90 if (unlikely(addr_len < sizeof(struct sockaddr_mptp))) {
91 log_error("Invalid size for sockaddr\n");
96 mptp_addr = (struct sockaddr_mptp *) addr;
98 port = mptp_addr->dests[0].port;
100 if (unlikely(port == 0 || port >= MAX_MPTP_PORT)) {
101 log_error("Invalid value for sockaddr port (%u)\n", port);
106 if (unlikely(mptp_lookup(port) != NULL)) {
107 log_error("Port %u already in use\n", port);
112 ssk = mptp_sk(sock->sk);
113 sock->sk->sk_rcvbuf = 10 * 1024 * 1024;
116 mptp_hash(port, ssk);
118 log_debug("Socket %p bound to port %u\n", ssk, port);
126 static int mptp_connect(struct socket *sock, struct sockaddr *addr, int addr_len, int flags)
130 struct inet_sock * isk;
131 struct mptp_sock * ssk;
133 log_debug("mptp_connect\n");
135 if (unlikely(sock == NULL)) {
136 log_error("Sock is NULL\n");
142 if (unlikely(sk == NULL)) {
143 log_error("Sock->sk is NULL\n");
151 if (unlikely(ssk->src != 0)) {
152 log_error("ssk->src is not NULL\n");
158 struct sockaddr_mptp * mptp_addr = (struct sockaddr_mptp *) addr;
160 if (unlikely(addr_len < sizeof(*mptp_addr) ||
161 addr_len < mptp_addr->count * sizeof(struct mptp_dest) ||
162 mptp_addr->count <= 0)) {
163 log_error("Invalid size or address family\n");
167 ssk->dst = mptp_addr->dests[0].port;
168 if (unlikely(ssk->dst == 0 || ssk->dst >= MAX_MPTP_PORT)) {
169 log_error("Invalid value for destination port(%u)\n", ssk->dst);
174 isk->inet_daddr = mptp_addr->dests[0].addr;
175 log_debug("Received from user space destination port=%u and address=%u\n", ssk->dst, isk->inet_daddr);
177 log_error("Invalid mptp_addr (NULL)\n");
182 ssk->src = get_next_free_port();
183 if (unlikely(ssk->src == 0)) {
184 log_error("No free ports\n");
189 mptp_hash(ssk->src, ssk);
197 static int mptp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, size_t len)
203 struct sk_buff * skb;
205 struct inet_sock * isk;
206 struct mptp_sock * ssk;
207 struct mptphdr * shdr;
210 struct rtable * rt = NULL;
213 struct sockaddr_mptp * mptp_addr = NULL;
215 if (unlikely(sock == NULL)) {
216 log_error("Sock is NULL\n");
222 if (unlikely(sk == NULL)) {
223 log_error("Sock->sk is NULL\n");
233 sport = get_next_free_port();
234 if (unlikely(sport == 0)) {
235 log_error("No free ports\n");
242 mptp_addr = (struct sockaddr_mptp *) msg->msg_name;
244 if (unlikely(msg->msg_namelen < sizeof(*mptp_addr) ||
245 msg->msg_namelen < mptp_addr->count * sizeof(struct mptp_dest) ||
246 mptp_addr->count <= 0)) {
247 log_error("Invalid size for msg_name\n");
252 dests = mptp_addr->count;
255 if (unlikely(!ssk->dst || !isk->inet_daddr)) {
256 log_error("No destination port/address\n");
261 daddr = isk->inet_daddr;
263 log_debug("Got from socket destination port=%u and address=%u\n", dport, daddr);
267 if (msg->msg_iovlen < dests)
268 dests = msg->msg_iovlen;
270 for (i = 0; i < dests; i++) {
271 struct mptp_dest *dest = &mptp_addr->dests[i];
272 struct iovec *iov = &msg->msg_iov[i];
276 if (unlikely(dport == 0 || dport >= MAX_MPTP_PORT)) {
277 log_error("Invalid value for destination port(%u)\n", dport);
283 log_debug("Received from user space destination port=%u and address=%u\n", dport, daddr);
286 totlen = len + sizeof(struct mptphdr) + sizeof(struct iphdr);
287 skb = sock_alloc_send_skb(sk, totlen, msg->msg_flags & MSG_DONTWAIT, &err);
288 if (unlikely(!skb)) {
289 log_error("sock_alloc_send_skb failed\n");
292 log_debug("Allocated %u bytes for skb (payload size=%u)\n", totlen, len);
294 skb_reset_network_header(skb);
295 skb_reserve(skb, sizeof(struct iphdr));
296 log_debug("Reseted network header\n");
297 skb_reset_transport_header(skb);
298 skb_put(skb, sizeof(struct mptphdr));
299 log_debug("Reseted transport header\n");
301 shdr = (struct mptphdr *) skb_transport_header(skb);
304 shdr->len = ntohs(len + sizeof(struct mptphdr));
306 payload = skb_put(skb, len);
307 log_debug("payload=%p\n", payload);
309 err = skb_copy_datagram_from_iovec(skb, sizeof(struct mptphdr), iov, 0, len);
311 log_error("skb_copy_datagram_from_iovec failed\n");
314 log_debug("Copied %u bytes into the skb\n", len);
317 rt = (struct rtable *) __sk_dst_check(sk, 0);
320 struct flowi fl = { .fl4_dst = daddr,
321 .proto = sk->sk_protocol,
322 .flags = inet_sk_flowi_flags(sk),
324 err = ip_route_output_flow(sock_net(sk), &rt, &fl, sk, 0);
326 log_error("Route lookup failed\n");
329 #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 36)
330 sk_dst_set(sk, dst_clone(&rt->u.dst));
332 sk_dst_set(sk, dst_clone(&rt->dst));
337 err = ip_queue_xmit(skb);
339 log_debug("Sent %u bytes on wire\n", len);
341 log_error("ip_queue_xmit failed\n");
353 static int mptp_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg, size_t len, int flags)
356 struct sockaddr_mptp *mptp_addr;
357 struct sock * sk = sock->sk;
360 struct sockaddr_mptp *ret_addr = (struct sockaddr_mptp *) msg->msg_name;
362 log_debug("Trying to receive sock=%p sk=%p flags=%d\n", sock, sk, flags);
364 skb = skb_recv_datagram(sk, flags, flags & MSG_DONTWAIT, &err);
365 if (unlikely(!skb)) {
366 log_error("skb_recv_datagram failed with %d\n", err);
370 for (i = 0; i < msg->msg_iovlen; i++) {
371 log_debug("Received skb %p\n", skb);
373 mptp_addr = (struct sockaddr_mptp *) skb->cb;
376 if (copied > msg->msg_iov[i].iov_len) {
377 copied = msg->msg_iov[i].iov_len;
378 msg->msg_flags |= MSG_TRUNC;
381 err = skb_copy_datagram_iovec(skb, 0, &msg->msg_iov[i], copied);
383 log_error("skb_copy_datagram_iovec\n");
386 log_debug("Received %d bytes\n", copied);
388 sock_recv_ts_and_drops(msg, sk, skb);
391 memcpy(&ret_addr->dests[i], &mptp_addr->dests[0], sizeof(ret_addr->dests[i]));
396 skb_free_datagram(sk, skb);
398 if (i == msg->msg_iovlen - 1)
401 skb = skb_recv_datagram(sk, flags, 1, &err);
402 if (likely(err == -EAGAIN)) {
403 log_debug("No more skbs in the queue, returning...\n");
409 ret_addr->count = i + 1;
410 msg->msg_namelen = sizeof(struct sockaddr_mptp) + (i + 1) * sizeof(struct mptp_dest);
416 static int mptp_rcv(struct sk_buff *skb)
418 struct mptphdr *shdr;
419 struct mptp_sock *ssk;
422 struct sockaddr_mptp * mptp_addr;
424 int addr_size = sizeof(struct sockaddr_mptp) + sizeof(struct mptp_dest);
426 if (unlikely(!pskb_may_pull(skb, sizeof(struct mptphdr)))) {
427 log_error("Insufficient space for header\n");
431 shdr = (struct mptphdr *) skb->data;
432 len = ntohs(shdr->len);
434 if (unlikely(skb->len < len)) {
435 log_error("Malformed packet (packet_len=%u, skb_len=%u)\n", len, skb->len);
439 if (unlikely(len < sizeof(struct mptphdr))) {
440 log_error("Malformed packet (packet_len=%u sizeof(mptphdr)=%u\n", len, sizeof(struct mptphdr));
446 if (unlikely(src == 0 || dst == 0 || src >= MAX_MPTP_PORT || dst >= MAX_MPTP_PORT)) {
447 log_error("Malformed packet (src=%u, dst=%u)\n", shdr->src, shdr->dst);
451 skb_pull(skb, sizeof(struct mptphdr));
452 len -= sizeof(struct mptphdr);
456 log_debug("Received %u bytes from from port=%u to port=%u\n", len - sizeof(struct mptphdr), src, dst);
458 ssk = mptp_lookup(dst);
460 log_error("MPTP lookup failed for port %u\n", dst);
464 BUG_ON(addr_size > sizeof(skb->cb));
466 mptp_addr = (struct sockaddr_mptp *) skb->cb;
467 mptp_addr->dests[0].port = shdr->src;
468 mptp_addr->dests[0].addr = ip_hdr(skb)->saddr;
470 log_debug("Setting sin_port=%u, sin_addr=%u\n", ntohs(shdr->src), mptp_addr->dests[0].addr);
472 err = ip_queue_rcv_skb((struct sock *) &ssk->sock, skb);
474 log_error("ip_queue_rcv_skb failed with %d\n", err);
477 return NET_RX_SUCCESS;
484 static struct proto mptp_prot = {
485 .obj_size = sizeof(struct mptp_sock),
486 .owner = THIS_MODULE,
490 static const struct proto_ops mptp_ops = {
492 .owner = THIS_MODULE,
493 .release = mptp_release,
495 .connect = mptp_connect,
496 .socketpair = sock_no_socketpair,
497 .accept = sock_no_accept,
498 .getname = sock_no_getname,
499 .poll = datagram_poll,
500 .ioctl = sock_no_ioctl,
501 .listen = sock_no_listen,
502 .shutdown = sock_no_shutdown,
503 .setsockopt = sock_no_setsockopt,
504 .getsockopt = sock_no_getsockopt,
505 .sendmsg = mptp_sendmsg,
506 .recvmsg = mptp_recvmsg,
507 .mmap = sock_no_mmap,
508 .sendpage = sock_no_sendpage,
511 static const struct net_protocol mptp_protocol = {
517 static struct inet_protosw mptp_protosw = {
519 .protocol = IPPROTO_MPTP,
525 static int __init mptp_init(void)
529 rc = proto_register(&mptp_prot, 1);
531 log_error("Error registering mptp protocol\n");
535 rc = inet_add_protocol(&mptp_protocol, IPPROTO_MPTP);
537 log_error("Error adding mptp protocol\n");
541 inet_register_protosw(&mptp_protosw);
542 log_debug("MPTP entered\n");
547 proto_unregister(&mptp_prot);
553 static void __exit mptp_exit(void)
555 inet_unregister_protosw(&mptp_protosw);
557 inet_del_protocol(&mptp_protocol, IPPROTO_MPTP);
559 proto_unregister(&mptp_prot);
561 log_debug("MPTP exited\n");
564 module_init(mptp_init);
565 module_exit(mptp_exit);