| /* |
| * INET An implementation of the TCP/IP protocol suite for the LINUX |
| * operating system. INET is implemented using the BSD Socket |
| * interface as the means of communication with the user level. |
| * |
| * UDP for IPv4. |
| * |
| * For full credits, see net/ipv4/udp.c. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| |
| #include <asm/system.h> |
| #include <asm/uaccess.h> |
| #include <asm/ioctls.h> |
| #include <linux/bootmem.h> |
| #include <linux/types.h> |
| #include <linux/fcntl.h> |
| #include <linux/module.h> |
| #include <linux/socket.h> |
| #include <linux/sockios.h> |
| #include <linux/igmp.h> |
| #include <linux/in.h> |
| #include <linux/errno.h> |
| #include <linux/timer.h> |
| #include <linux/mm.h> |
| #include <linux/inet.h> |
| #include <linux/netdevice.h> |
| #include <net/tcp_states.h> |
| #include <linux/skbuff.h> |
| #include <linux/proc_fs.h> |
| #include <linux/seq_file.h> |
| #include <net/net_namespace.h> |
| #include <net/icmp.h> |
| #include <net/route.h> |
| #include <net/checksum.h> |
| #include <net/xfrm.h> |
| #include "udp_impl.h" |
| |
| int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2) |
| { |
| struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2); |
| |
| return ( !ipv6_only_sock(sk2) && |
| (!inet1->rcv_saddr || !inet2->rcv_saddr || |
| inet1->rcv_saddr == inet2->rcv_saddr )); |
| } |
| |
| static inline int udp_v4_get_port(struct sock *sk, unsigned short snum) |
| { |
| return udp_get_port(sk, snum, ipv4_rcv_saddr_equal); |
| } |
| |
| /* UDP is nearly always wildcards out the wazoo, it makes no sense to try |
| * harder than this. -DaveM |
| */ |
| static struct sock *__udp4_lib_lookup(struct net *net, __be32 saddr, |
| __be16 sport, __be32 daddr, __be16 dport, |
| int dif, struct hlist_head udptable[]) |
| { |
| struct sock *sk, *result = NULL; |
| struct hlist_node *node; |
| unsigned short hnum = ntohs(dport); |
| int badness = -1; |
| |
| read_lock(&udp_hash_lock); |
| sk_for_each(sk, node, &udptable[hnum & (UDP_HTABLE_SIZE - 1)]) { |
| struct inet_sock *inet = inet_sk(sk); |
| |
| if (sk->sk_net == net && sk->sk_hash == hnum && |
| !ipv6_only_sock(sk)) { |
| int score = (sk->sk_family == PF_INET ? 1 : 0); |
| if (inet->rcv_saddr) { |
| if (inet->rcv_saddr != daddr) |
| continue; |
| score+=2; |
| } |
| if (inet->daddr) { |
| if (inet->daddr != saddr) |
| continue; |
| score+=2; |
| } |
| if (inet->dport) { |
| if (inet->dport != sport) |
| continue; |
| score+=2; |
| } |
| if (sk->sk_bound_dev_if) { |
| if (sk->sk_bound_dev_if != dif) |
| continue; |
| score+=2; |
| } |
| if (score == 9) { |
| result = sk; |
| break; |
| } else if (score > badness) { |
| result = sk; |
| badness = score; |
| } |
| } |
| } |
| if (result) |
| sock_hold(result); |
| read_unlock(&udp_hash_lock); |
| return result; |
| } |
| |
| static inline struct sock *udp_v4_mcast_next(struct sock *sk, |
| __be16 loc_port, __be32 loc_addr, |
| __be16 rmt_port, __be32 rmt_addr, |
| int dif) |
| { |
| struct hlist_node *node; |
| struct sock *s = sk; |
| unsigned short hnum = ntohs(loc_port); |
| |
| sk_for_each_from(s, node) { |
| struct inet_sock *inet = inet_sk(s); |
| |
| if (s->sk_hash != hnum || |
| (inet->daddr && inet->daddr != rmt_addr) || |
| (inet->dport != rmt_port && inet->dport) || |
| (inet->rcv_saddr && inet->rcv_saddr != loc_addr) || |
| ipv6_only_sock(s) || |
| (s->sk_bound_dev_if && s->sk_bound_dev_if != dif)) |
| continue; |
| if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif)) |
| continue; |
| goto found; |
| } |
| s = NULL; |
| found: |
| return s; |
| } |
| |
| /* |
| * This routine is called by the ICMP module when it gets some |
| * sort of error condition. If err < 0 then the socket should |
| * be closed and the error returned to the user. If err > 0 |
| * it's just the icmp type << 8 | icmp code. |
| * Header points to the ip header of the error packet. We move |
| * on past this. Then (as it used to claim before adjustment) |
| * header points to the first 8 bytes of the udp header. We need |
| * to find the appropriate port. |
| */ |
| |
| void __udp4_lib_err(struct sk_buff *skb, u32 info, struct hlist_head udptable[]) |
| { |
| struct inet_sock *inet; |
| struct iphdr *iph = (struct iphdr*)skb->data; |
| struct udphdr *uh = (struct udphdr*)(skb->data+(iph->ihl<<2)); |
| const int type = icmp_hdr(skb)->type; |
| const int code = icmp_hdr(skb)->code; |
| struct sock *sk; |
| int harderr; |
| int err; |
| |
| sk = __udp4_lib_lookup(skb->dev->nd_net, iph->daddr, uh->dest, |
| iph->saddr, uh->source, skb->dev->ifindex, udptable); |
| if (sk == NULL) { |
| ICMP_INC_STATS_BH(ICMP_MIB_INERRORS); |
| return; /* No socket for error */ |
| } |
| |
| err = 0; |
| harderr = 0; |
| inet = inet_sk(sk); |
| |
| switch (type) { |
| default: |
| case ICMP_TIME_EXCEEDED: |
| err = EHOSTUNREACH; |
| break; |
| case ICMP_SOURCE_QUENCH: |
| goto out; |
| case ICMP_PARAMETERPROB: |
| err = EPROTO; |
| harderr = 1; |
| break; |
| case ICMP_DEST_UNREACH: |
| if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */ |
| if (inet->pmtudisc != IP_PMTUDISC_DONT) { |
| err = EMSGSIZE; |
| harderr = 1; |
| break; |
| } |
| goto out; |
| } |
| err = EHOSTUNREACH; |
| if (code <= NR_ICMP_UNREACH) { |
| harderr = icmp_err_convert[code].fatal; |
| err = icmp_err_convert[code].errno; |
| } |
| break; |
| } |
| |
| /* |
| * RFC1122: OK. Passes ICMP errors back to application, as per |
| * 4.1.3.3. |
| */ |
| if (!inet->recverr) { |
| if (!harderr || sk->sk_state != TCP_ESTABLISHED) |
| goto out; |
| } else { |
| ip_icmp_error(sk, skb, err, uh->dest, info, (u8*)(uh+1)); |
| } |
| sk->sk_err = err; |
| sk->sk_error_report(sk); |
| out: |
| sock_put(sk); |
| } |
| |
| void udp_err(struct sk_buff *skb, u32 info) |
| { |
| __udp4_lib_err(skb, info, udp_hash); |
| } |
| |
| /* |
| * Throw away all pending data and cancel the corking. Socket is locked. |
| */ |
| static void udp_flush_pending_frames(struct sock *sk) |
| { |
| struct udp_sock *up = udp_sk(sk); |
| |
| if (up->pending) { |
| up->len = 0; |
| up->pending = 0; |
| ip_flush_pending_frames(sk); |
| } |
| } |
| |
| /** |
| * udp4_hwcsum_outgoing - handle outgoing HW checksumming |
| * @sk: socket we are sending on |
| * @skb: sk_buff containing the filled-in UDP header |
| * (checksum field must be zeroed out) |
| */ |
| static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb, |
| __be32 src, __be32 dst, int len ) |
| { |
| unsigned int offset; |
| struct udphdr *uh = udp_hdr(skb); |
| __wsum csum = 0; |
| |
| if (skb_queue_len(&sk->sk_write_queue) == 1) { |
| /* |
| * Only one fragment on the socket. |
| */ |
| skb->csum_start = skb_transport_header(skb) - skb->head; |
| skb->csum_offset = offsetof(struct udphdr, check); |
| uh->check = ~csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, 0); |
| } else { |
| /* |
| * HW-checksum won't work as there are two or more |
| * fragments on the socket so that all csums of sk_buffs |
| * should be together |
| */ |
| offset = skb_transport_offset(skb); |
| skb->csum = skb_checksum(skb, offset, skb->len - offset, 0); |
| |
| skb->ip_summed = CHECKSUM_NONE; |
| |
| skb_queue_walk(&sk->sk_write_queue, skb) { |
| csum = csum_add(csum, skb->csum); |
| } |
| |
| uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum); |
| if (uh->check == 0) |
| uh->check = CSUM_MANGLED_0; |
| } |
| } |
| |
| /* |
| * Push out all pending data as one UDP datagram. Socket is locked. |
| */ |
| static int udp_push_pending_frames(struct sock *sk) |
| { |
| struct udp_sock *up = udp_sk(sk); |
| struct inet_sock *inet = inet_sk(sk); |
| struct flowi *fl = &inet->cork.fl; |
| struct sk_buff *skb; |
| struct udphdr *uh; |
| int err = 0; |
| int is_udplite = IS_UDPLITE(sk); |
| __wsum csum = 0; |
| |
| /* Grab the skbuff where UDP header space exists. */ |
| if ((skb = skb_peek(&sk->sk_write_queue)) == NULL) |
| goto out; |
| |
| /* |
| * Create a UDP header |
| */ |
| uh = udp_hdr(skb); |
| uh->source = fl->fl_ip_sport; |
| uh->dest = fl->fl_ip_dport; |
| uh->len = htons(up->len); |
| uh->check = 0; |
| |
| if (is_udplite) /* UDP-Lite */ |
| csum = udplite_csum_outgoing(sk, skb); |
| |
| else if (sk->sk_no_check == UDP_CSUM_NOXMIT) { /* UDP csum disabled */ |
| |
| skb->ip_summed = CHECKSUM_NONE; |
| goto send; |
| |
| } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */ |
| |
| udp4_hwcsum_outgoing(sk, skb, fl->fl4_src,fl->fl4_dst, up->len); |
| goto send; |
| |
| } else /* `normal' UDP */ |
| csum = udp_csum_outgoing(sk, skb); |
| |
| /* add protocol-dependent pseudo-header */ |
| uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len, |
| sk->sk_protocol, csum ); |
| if (uh->check == 0) |
| uh->check = CSUM_MANGLED_0; |
| |
| send: |
| err = ip_push_pending_frames(sk); |
| out: |
| up->len = 0; |
| up->pending = 0; |
| if (!err) |
| UDP_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS, is_udplite); |
| return err; |
| } |
| |
| int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, |
| size_t len) |
| { |
| struct inet_sock *inet = inet_sk(sk); |
| struct udp_sock *up = udp_sk(sk); |
| int ulen = len; |
| struct ipcm_cookie ipc; |
| struct rtable *rt = NULL; |
| int free = 0; |
| int connected = 0; |
| __be32 daddr, faddr, saddr; |
| __be16 dport; |
| u8 tos; |
| int err, is_udplite = IS_UDPLITE(sk); |
| int corkreq = up->corkflag || msg->msg_flags&MSG_MORE; |
| int (*getfrag)(void *, char *, int, int, int, struct sk_buff *); |
| |
| if (len > 0xFFFF) |
| return -EMSGSIZE; |
| |
| /* |
| * Check the flags. |
| */ |
| |
| if (msg->msg_flags&MSG_OOB) /* Mirror BSD error message compatibility */ |
| return -EOPNOTSUPP; |
| |
| ipc.opt = NULL; |
| |
| if (up->pending) { |
| /* |
| * There are pending frames. |
| * The socket lock must be held while it's corked. |
| */ |
| lock_sock(sk); |
| if (likely(up->pending)) { |
| if (unlikely(up->pending != AF_INET)) { |
| release_sock(sk); |
| return -EINVAL; |
| } |
| goto do_append_data; |
| } |
| release_sock(sk); |
| } |
| ulen += sizeof(struct udphdr); |
| |
| /* |
| * Get and verify the address. |
| */ |
| if (msg->msg_name) { |
| struct sockaddr_in * usin = (struct sockaddr_in*)msg->msg_name; |
| if (msg->msg_namelen < sizeof(*usin)) |
| return -EINVAL; |
| if (usin->sin_family != AF_INET) { |
| if (usin->sin_family != AF_UNSPEC) |
| return -EAFNOSUPPORT; |
| } |
| |
| daddr = usin->sin_addr.s_addr; |
| dport = usin->sin_port; |
| if (dport == 0) |
| return -EINVAL; |
| } else { |
| if (sk->sk_state != TCP_ESTABLISHED) |
| return -EDESTADDRREQ; |
| daddr = inet->daddr; |
| dport = inet->dport; |
| /* Open fast path for connected socket. |
| Route will not be used, if at least one option is set. |
| */ |
| connected = 1; |
| } |
| ipc.addr = inet->saddr; |
| |
| ipc.oif = sk->sk_bound_dev_if; |
| if (msg->msg_controllen) { |
| err = ip_cmsg_send(msg, &ipc); |
| if (err) |
| return err; |
| if (ipc.opt) |
| free = 1; |
| connected = 0; |
| } |
| if (!ipc.opt) |
| ipc.opt = inet->opt; |
| |
| saddr = ipc.addr; |
| ipc.addr = faddr = daddr; |
| |
| if (ipc.opt && ipc.opt->srr) { |
| if (!daddr) |
| return -EINVAL; |
| faddr = ipc.opt->faddr; |
| connected = 0; |
| } |
| tos = RT_TOS(inet->tos); |
| if (sock_flag(sk, SOCK_LOCALROUTE) || |
| (msg->msg_flags & MSG_DONTROUTE) || |
| (ipc.opt && ipc.opt->is_strictroute)) { |
| tos |= RTO_ONLINK; |
| connected = 0; |
| } |
| |
| if (ipv4_is_multicast(daddr)) { |
| if (!ipc.oif) |
| ipc.oif = inet->mc_index; |
| if (!saddr) |
| saddr = inet->mc_addr; |
| connected = 0; |
| } |
| |
| if (connected) |
| rt = (struct rtable*)sk_dst_check(sk, 0); |
| |
| if (rt == NULL) { |
| struct flowi fl = { .oif = ipc.oif, |
| .nl_u = { .ip4_u = |
| { .daddr = faddr, |
| .saddr = saddr, |
| .tos = tos } }, |
| .proto = sk->sk_protocol, |
| .uli_u = { .ports = |
| { .sport = inet->sport, |
| .dport = dport } } }; |
| security_sk_classify_flow(sk, &fl); |
| err = ip_route_output_flow(&init_net, &rt, &fl, sk, 1); |
| if (err) { |
| if (err == -ENETUNREACH) |
| IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES); |
| goto out; |
| } |
| |
| err = -EACCES; |
| if ((rt->rt_flags & RTCF_BROADCAST) && |
| !sock_flag(sk, SOCK_BROADCAST)) |
| goto out; |
| if (connected) |
| sk_dst_set(sk, dst_clone(&rt->u.dst)); |
| } |
| |
| if (msg->msg_flags&MSG_CONFIRM) |
| goto do_confirm; |
| back_from_confirm: |
| |
| saddr = rt->rt_src; |
| if (!ipc.addr) |
| daddr = ipc.addr = rt->rt_dst; |
| |
| lock_sock(sk); |
| if (unlikely(up->pending)) { |
| /* The socket is already corked while preparing it. */ |
| /* ... which is an evident application bug. --ANK */ |
| release_sock(sk); |
| |
| LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n"); |
| err = -EINVAL; |
| goto out; |
| } |
| /* |
| * Now cork the socket to pend data. |
| */ |
| inet->cork.fl.fl4_dst = daddr; |
| inet->cork.fl.fl_ip_dport = dport; |
| inet->cork.fl.fl4_src = saddr; |
| inet->cork.fl.fl_ip_sport = inet->sport; |
| up->pending = AF_INET; |
| |
| do_append_data: |
| up->len += ulen; |
| getfrag = is_udplite ? udplite_getfrag : ip_generic_getfrag; |
| err = ip_append_data(sk, getfrag, msg->msg_iov, ulen, |
| sizeof(struct udphdr), &ipc, rt, |
| corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags); |
| if (err) |
| udp_flush_pending_frames(sk); |
| else if (!corkreq) |
| err = udp_push_pending_frames(sk); |
| else if (unlikely(skb_queue_empty(&sk->sk_write_queue))) |
| up->pending = 0; |
| release_sock(sk); |
| |
| out: |
| ip_rt_put(rt); |
| if (free) |
| kfree(ipc.opt); |
| if (!err) |
| return len; |
| /* |
| * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space. Reporting |
| * ENOBUFS might not be good (it's not tunable per se), but otherwise |
| * we don't have a good statistic (IpOutDiscards but it can be too many |
| * things). We could add another new stat but at least for now that |
| * seems like overkill. |
| */ |
| if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) { |
| UDP_INC_STATS_USER(UDP_MIB_SNDBUFERRORS, is_udplite); |
| } |
| return err; |
| |
| do_confirm: |
| dst_confirm(&rt->u.dst); |
| if (!(msg->msg_flags&MSG_PROBE) || len) |
| goto back_from_confirm; |
| err = 0; |
| goto out; |
| } |
| |
| int udp_sendpage(struct sock *sk, struct page *page, int offset, |
| size_t size, int flags) |
| { |
| struct udp_sock *up = udp_sk(sk); |
| int ret; |
| |
| if (!up->pending) { |
| struct msghdr msg = { .msg_flags = flags|MSG_MORE }; |
| |
| /* Call udp_sendmsg to specify destination address which |
| * sendpage interface can't pass. |
| * This will succeed only when the socket is connected. |
| */ |
| ret = udp_sendmsg(NULL, sk, &msg, 0); |
| if (ret < 0) |
| return ret; |
| } |
| |
| lock_sock(sk); |
| |
| if (unlikely(!up->pending)) { |
| release_sock(sk); |
| |
| LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 3\n"); |
| return -EINVAL; |
| } |
| |
| ret = ip_append_page(sk, page, offset, size, flags); |
| if (ret == -EOPNOTSUPP) { |
| release_sock(sk); |
| return sock_no_sendpage(sk->sk_socket, page, offset, |
| size, flags); |
| } |
| if (ret < 0) { |
| udp_flush_pending_frames(sk); |
| goto out; |
| } |
| |
| up->len += size; |
| if (!(up->corkflag || (flags&MSG_MORE))) |
| ret = udp_push_pending_frames(sk); |
| if (!ret) |
| ret = size; |
| out: |
| release_sock(sk); |
| return ret; |
| } |
| |
| /* |
| * This should be easy, if there is something there we |
| * return it, otherwise we block. |
| */ |
| |
| int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, |
| size_t len, int noblock, int flags, int *addr_len) |
| { |
| struct inet_sock *inet = inet_sk(sk); |
| struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name; |
| struct sk_buff *skb; |
| unsigned int ulen, copied; |
| int peeked; |
| int err; |
| int is_udplite = IS_UDPLITE(sk); |
| |
| /* |
| * Check any passed addresses |
| */ |
| if (addr_len) |
| *addr_len=sizeof(*sin); |
| |
| if (flags & MSG_ERRQUEUE) |
| return ip_recv_error(sk, msg, len); |
| |
| try_again: |
| skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0), |
| &peeked, &err); |
| if (!skb) |
| goto out; |
| |
| ulen = skb->len - sizeof(struct udphdr); |
| copied = len; |
| if (copied > ulen) |
| copied = ulen; |
| else if (copied < ulen) |
| msg->msg_flags |= MSG_TRUNC; |
| |
| /* |
| * If checksum is needed at all, try to do it while copying the |
| * data. If the data is truncated, or if we only want a partial |
| * coverage checksum (UDP-Lite), do it before the copy. |
| */ |
| |
| if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) { |
| if (udp_lib_checksum_complete(skb)) |
| goto csum_copy_err; |
| } |
| |
| if (skb_csum_unnecessary(skb)) |
| err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), |
| msg->msg_iov, copied ); |
| else { |
| err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov); |
| |
| if (err == -EINVAL) |
| goto csum_copy_err; |
| } |
| |
| if (err) |
| goto out_free; |
| |
| if (!peeked) |
| UDP_INC_STATS_USER(UDP_MIB_INDATAGRAMS, is_udplite); |
| |
| sock_recv_timestamp(msg, sk, skb); |
| |
| /* Copy the address. */ |
| if (sin) |
| { |
| sin->sin_family = AF_INET; |
| sin->sin_port = udp_hdr(skb)->source; |
| sin->sin_addr.s_addr = ip_hdr(skb)->saddr; |
| memset(sin->sin_zero, 0, sizeof(sin->sin_zero)); |
| } |
| if (inet->cmsg_flags) |
| ip_cmsg_recv(msg, skb); |
| |
| err = copied; |
| if (flags & MSG_TRUNC) |
| err = ulen; |
| |
| out_free: |
| lock_sock(sk); |
| skb_free_datagram(sk, skb); |
| release_sock(sk); |
| out: |
| return err; |
| |
| csum_copy_err: |
| lock_sock(sk); |
| if (!skb_kill_datagram(sk, skb, flags)) |
| UDP_INC_STATS_USER(UDP_MIB_INERRORS, is_udplite); |
| release_sock(sk); |
| |
| if (noblock) |
| return -EAGAIN; |
| goto try_again; |
| } |
| |
| |
| /* returns: |
| * -1: error |
| * 0: success |
| * >0: "udp encap" protocol resubmission |
| * |
| * Note that in the success and error cases, the skb is assumed to |
| * have either been requeued or freed. |
| */ |
| int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb) |
| { |
| struct udp_sock *up = udp_sk(sk); |
| int rc; |
| int is_udplite = IS_UDPLITE(sk); |
| |
| /* |
| * Charge it to the socket, dropping if the queue is full. |
| */ |
| if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) |
| goto drop; |
| nf_reset(skb); |
| |
| if (up->encap_type) { |
| /* |
| * This is an encapsulation socket so pass the skb to |
| * the socket's udp_encap_rcv() hook. Otherwise, just |
| * fall through and pass this up the UDP socket. |
| * up->encap_rcv() returns the following value: |
| * =0 if skb was successfully passed to the encap |
| * handler or was discarded by it. |
| * >0 if skb should be passed on to UDP. |
| * <0 if skb should be resubmitted as proto -N |
| */ |
| |
| /* if we're overly short, let UDP handle it */ |
| if (skb->len > sizeof(struct udphdr) && |
| up->encap_rcv != NULL) { |
| int ret; |
| |
| ret = (*up->encap_rcv)(sk, skb); |
| if (ret <= 0) { |
| UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, |
| is_udplite); |
| return -ret; |
| } |
| } |
| |
| /* FALLTHROUGH -- it's a UDP Packet */ |
| } |
| |
| /* |
| * UDP-Lite specific tests, ignored on UDP sockets |
| */ |
| if ((is_udplite & UDPLITE_RECV_CC) && UDP_SKB_CB(skb)->partial_cov) { |
| |
| /* |
| * MIB statistics other than incrementing the error count are |
| * disabled for the following two types of errors: these depend |
| * on the application settings, not on the functioning of the |
| * protocol stack as such. |
| * |
| * RFC 3828 here recommends (sec 3.3): "There should also be a |
| * way ... to ... at least let the receiving application block |
| * delivery of packets with coverage values less than a value |
| * provided by the application." |
| */ |
| if (up->pcrlen == 0) { /* full coverage was set */ |
| LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: partial coverage " |
| "%d while full coverage %d requested\n", |
| UDP_SKB_CB(skb)->cscov, skb->len); |
| goto drop; |
| } |
| /* The next case involves violating the min. coverage requested |
| * by the receiver. This is subtle: if receiver wants x and x is |
| * greater than the buffersize/MTU then receiver will complain |
| * that it wants x while sender emits packets of smaller size y. |
| * Therefore the above ...()->partial_cov statement is essential. |
| */ |
| if (UDP_SKB_CB(skb)->cscov < up->pcrlen) { |
| LIMIT_NETDEBUG(KERN_WARNING |
| "UDPLITE: coverage %d too small, need min %d\n", |
| UDP_SKB_CB(skb)->cscov, up->pcrlen); |
| goto drop; |
| } |
| } |
| |
| if (sk->sk_filter) { |
| if (udp_lib_checksum_complete(skb)) |
| goto drop; |
| } |
| |
| if ((rc = sock_queue_rcv_skb(sk,skb)) < 0) { |
| /* Note that an ENOMEM error is charged twice */ |
| if (rc == -ENOMEM) |
| UDP_INC_STATS_BH(UDP_MIB_RCVBUFERRORS, is_udplite); |
| goto drop; |
| } |
| |
| return 0; |
| |
| drop: |
| UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_udplite); |
| kfree_skb(skb); |
| return -1; |
| } |
| |
| /* |
| * Multicasts and broadcasts go to each listener. |
| * |
| * Note: called only from the BH handler context, |
| * so we don't need to lock the hashes. |
| */ |
| static int __udp4_lib_mcast_deliver(struct sk_buff *skb, |
| struct udphdr *uh, |
| __be32 saddr, __be32 daddr, |
| struct hlist_head udptable[]) |
| { |
| struct sock *sk; |
| int dif; |
| |
| read_lock(&udp_hash_lock); |
| sk = sk_head(&udptable[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)]); |
| dif = skb->dev->ifindex; |
| sk = udp_v4_mcast_next(sk, uh->dest, daddr, uh->source, saddr, dif); |
| if (sk) { |
| struct sock *sknext = NULL; |
| |
| do { |
| struct sk_buff *skb1 = skb; |
| |
| sknext = udp_v4_mcast_next(sk_next(sk), uh->dest, daddr, |
| uh->source, saddr, dif); |
| if (sknext) |
| skb1 = skb_clone(skb, GFP_ATOMIC); |
| |
| if (skb1) { |
| int ret = 0; |
| |
| bh_lock_sock_nested(sk); |
| if (!sock_owned_by_user(sk)) |
| ret = udp_queue_rcv_skb(sk, skb1); |
| else |
| sk_add_backlog(sk, skb1); |
| bh_unlock_sock(sk); |
| |
| if (ret > 0) |
| /* we should probably re-process instead |
| * of dropping packets here. */ |
| kfree_skb(skb1); |
| } |
| sk = sknext; |
| } while (sknext); |
| } else |
| kfree_skb(skb); |
| read_unlock(&udp_hash_lock); |
| return 0; |
| } |
| |
| /* Initialize UDP checksum. If exited with zero value (success), |
| * CHECKSUM_UNNECESSARY means, that no more checks are required. |
| * Otherwise, csum completion requires chacksumming packet body, |
| * including udp header and folding it to skb->csum. |
| */ |
| static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh, |
| int proto) |
| { |
| const struct iphdr *iph; |
| int err; |
| |
| UDP_SKB_CB(skb)->partial_cov = 0; |
| UDP_SKB_CB(skb)->cscov = skb->len; |
| |
| if (IS_PROTO_UDPLITE(proto)) { |
| err = udplite_checksum_init(skb, uh); |
| if (err) |
| return err; |
| } |
| |
| iph = ip_hdr(skb); |
| if (uh->check == 0) { |
| skb->ip_summed = CHECKSUM_UNNECESSARY; |
| } else if (skb->ip_summed == CHECKSUM_COMPLETE) { |
| if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len, |
| proto, skb->csum)) |
| skb->ip_summed = CHECKSUM_UNNECESSARY; |
| } |
| if (!skb_csum_unnecessary(skb)) |
| skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, |
| skb->len, proto, 0); |
| /* Probably, we should checksum udp header (it should be in cache |
| * in any case) and data in tiny packets (< rx copybreak). |
| */ |
| |
| return 0; |
| } |
| |
| /* |
| * All we need to do is get the socket, and then do a checksum. |
| */ |
| |
| int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[], |
| int proto) |
| { |
| struct sock *sk; |
| struct udphdr *uh = udp_hdr(skb); |
| unsigned short ulen; |
| struct rtable *rt = skb->rtable; |
| __be32 saddr = ip_hdr(skb)->saddr; |
| __be32 daddr = ip_hdr(skb)->daddr; |
| |
| /* |
| * Validate the packet. |
| */ |
| if (!pskb_may_pull(skb, sizeof(struct udphdr))) |
| goto drop; /* No space for header. */ |
| |
| ulen = ntohs(uh->len); |
| if (ulen > skb->len) |
| goto short_packet; |
| |
| if (IS_PROTO_UDPLITE(proto)) { |
| /* UDP validates ulen. */ |
| if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen)) |
| goto short_packet; |
| uh = udp_hdr(skb); |
| } |
| |
| if (udp4_csum_init(skb, uh, proto)) |
| goto csum_error; |
| |
| if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST)) |
| return __udp4_lib_mcast_deliver(skb, uh, saddr, daddr, udptable); |
| |
| sk = __udp4_lib_lookup(skb->dev->nd_net, saddr, uh->source, daddr, |
| uh->dest, inet_iif(skb), udptable); |
| |
| if (sk != NULL) { |
| int ret = 0; |
| bh_lock_sock_nested(sk); |
| if (!sock_owned_by_user(sk)) |
| ret = udp_queue_rcv_skb(sk, skb); |
| else |
| sk_add_backlog(sk, skb); |
| bh_unlock_sock(sk); |
| sock_put(sk); |
| |
| /* a return value > 0 means to resubmit the input, but |
| * it wants the return to be -protocol, or 0 |
| */ |
| if (ret > 0) |
| return -ret; |
| return 0; |
| } |
| |
| if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) |
| goto drop; |
| nf_reset(skb); |
| |
| /* No socket. Drop packet silently, if checksum is wrong */ |
| if (udp_lib_checksum_complete(skb)) |
| goto csum_error; |
| |
| UDP_INC_STATS_BH(UDP_MIB_NOPORTS, IS_PROTO_UDPLITE(proto)); |
| icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); |
| |
| /* |
| * Hmm. We got an UDP packet to a port to which we |
| * don't wanna listen. Ignore it. |
| */ |
| kfree_skb(skb); |
| return 0; |
| |
| short_packet: |
| LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %u.%u.%u.%u:%u %d/%d to %u.%u.%u.%u:%u\n", |
| IS_PROTO_UDPLITE(proto) ? "-Lite" : "", |
| NIPQUAD(saddr), |
| ntohs(uh->source), |
| ulen, |
| skb->len, |
| NIPQUAD(daddr), |
| ntohs(uh->dest)); |
| goto drop; |
| |
| csum_error: |
| /* |
| * RFC1122: OK. Discards the bad packet silently (as far as |
| * the network is concerned, anyway) as per 4.1.3.4 (MUST). |
| */ |
| LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %d.%d.%d.%d:%d to %d.%d.%d.%d:%d ulen %d\n", |
| IS_PROTO_UDPLITE(proto) ? "-Lite" : "", |
| NIPQUAD(saddr), |
| ntohs(uh->source), |
| NIPQUAD(daddr), |
| ntohs(uh->dest), |
| ulen); |
| drop: |
| UDP_INC_STATS_BH(UDP_MIB_INERRORS, IS_PROTO_UDPLITE(proto)); |
| kfree_skb(skb); |
| return 0; |
| } |
| |
| int udp_rcv(struct sk_buff *skb) |
| { |
| return __udp4_lib_rcv(skb, udp_hash, IPPROTO_UDP); |
| } |
| |
| int udp_destroy_sock(struct sock *sk) |
| { |
| lock_sock(sk); |
| udp_flush_pending_frames(sk); |
| release_sock(sk); |
| return 0; |
| } |
| |
| int udp_setsockopt(struct sock *sk, int level, int optname, |
| char __user *optval, int optlen) |
| { |
| if (IS_SOL_UDPFAMILY(level)) |
| return udp_lib_setsockopt(sk, level, optname, optval, optlen, |
| udp_push_pending_frames); |
| return ip_setsockopt(sk, level, optname, optval, optlen); |
| } |
| |
| #ifdef CONFIG_COMPAT |
| int compat_udp_setsockopt(struct sock *sk, int level, int optname, |
| char __user *optval, int optlen) |
| { |
| if (IS_SOL_UDPFAMILY(level)) |
| return udp_lib_setsockopt(sk, level, optname, optval, optlen, |
| udp_push_pending_frames); |
| return compat_ip_setsockopt(sk, level, optname, optval, optlen); |
| } |
| #endif |
| |
| int udp_getsockopt(struct sock *sk, int level, int optname, |
| char __user *optval, int __user *optlen) |
| { |
| if (IS_SOL_UDPFAMILY(level)) |
| return udp_lib_getsockopt(sk, level, optname, optval, optlen); |
| return ip_getsockopt(sk, level, optname, optval, optlen); |
| } |
| |
| #ifdef CONFIG_COMPAT |
| int compat_udp_getsockopt(struct sock *sk, int level, int optname, |
| char __user *optval, int __user *optlen) |
| { |
| if (IS_SOL_UDPFAMILY(level)) |
| return udp_lib_getsockopt(sk, level, optname, optval, optlen); |
| return compat_ip_getsockopt(sk, level, optname, optval, optlen); |
| } |
| #endif |
| |
| /* ------------------------------------------------------------------------ */ |
| DEFINE_PROTO_INUSE(udp) |
| |
| struct proto udp_prot = { |
| .name = "UDP", |
| .owner = THIS_MODULE, |
| .close = udp_lib_close, |
| .connect = ip4_datagram_connect, |
| .disconnect = udp_disconnect, |
| .ioctl = udp_ioctl, |
| .destroy = udp_destroy_sock, |
| .setsockopt = udp_setsockopt, |
| .getsockopt = udp_getsockopt, |
| .sendmsg = udp_sendmsg, |
| .recvmsg = udp_recvmsg, |
| .sendpage = udp_sendpage, |
| .backlog_rcv = udp_queue_rcv_skb, |
| .hash = udp_lib_hash, |
| .unhash = udp_lib_unhash, |
| .get_port = udp_v4_get_port, |
| .memory_allocated = &udp_memory_allocated, |
| .sysctl_mem = sysctl_udp_mem, |
| .sysctl_wmem = &sysctl_udp_wmem_min, |
| .sysctl_rmem = &sysctl_udp_rmem_min, |
| .obj_size = sizeof(struct udp_sock), |
| #ifdef CONFIG_COMPAT |
| .compat_setsockopt = compat_udp_setsockopt, |
| .compat_getsockopt = compat_udp_getsockopt, |
| #endif |
| REF_PROTO_INUSE(udp) |
| }; |
| |
| /* ------------------------------------------------------------------------ */ |
| static void udp4_format_sock(struct sock *sp, char *tmpbuf, int bucket) |
| { |
| struct inet_sock *inet = inet_sk(sp); |
| __be32 dest = inet->daddr; |
| __be32 src = inet->rcv_saddr; |
| __u16 destp = ntohs(inet->dport); |
| __u16 srcp = ntohs(inet->sport); |
| |
| sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X" |
| " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p", |
| bucket, src, srcp, dest, destp, sp->sk_state, |
| atomic_read(&sp->sk_wmem_alloc), |
| atomic_read(&sp->sk_rmem_alloc), |
| 0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp), |
| atomic_read(&sp->sk_refcnt), sp); |
| } |
| |
| int udp4_seq_show(struct seq_file *seq, void *v) |
| { |
| if (v == SEQ_START_TOKEN) |
| seq_printf(seq, "%-127s\n", |
| " sl local_address rem_address st tx_queue " |
| "rx_queue tr tm->when retrnsmt uid timeout " |
| "inode"); |
| else { |
| char tmpbuf[129]; |
| struct udp_iter_state *state = seq->private; |
| |
| udp4_format_sock(v, tmpbuf, state->bucket); |
| seq_printf(seq, "%-127s\n", tmpbuf); |
| } |
| return 0; |
| } |
| |
| /* ------------------------------------------------------------------------ */ |
| #ifdef CONFIG_PROC_FS |
| static struct file_operations udp4_seq_fops; |
| static struct udp_seq_afinfo udp4_seq_afinfo = { |
| .owner = THIS_MODULE, |
| .name = "udp", |
| .family = AF_INET, |
| .hashtable = udp_hash, |
| .seq_show = udp4_seq_show, |
| .seq_fops = &udp4_seq_fops, |
| }; |
| |
| int __init udp4_proc_init(void) |
| { |
| return udp_proc_register(&udp4_seq_afinfo); |
| } |
| |
| void udp4_proc_exit(void) |
| { |
| udp_proc_unregister(&udp4_seq_afinfo); |
| } |
| #endif /* CONFIG_PROC_FS */ |
| |
| EXPORT_SYMBOL(udp_prot); |
| EXPORT_SYMBOL(udp_sendmsg); |
| |