/* * 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. * * RAW - implementation of IP "raw" sockets. * * Version: $Id: raw.c,v 1.39.2.1 1999/06/20 20:14:50 davem Exp $ * * Authors: Ross Biro, * Fred N. van Kempen, * * Fixes: * Alan Cox : verify_area() fixed up * Alan Cox : ICMP error handling * Alan Cox : EMSGSIZE if you send too big a packet * Alan Cox : Now uses generic datagrams and shared skbuff * library. No more peek crashes, no more backlogs * Alan Cox : Checks sk->broadcast. * Alan Cox : Uses skb_free_datagram/skb_copy_datagram * Alan Cox : Raw passes ip options too * Alan Cox : Setsocketopt added * Alan Cox : Fixed error return for broadcasts * Alan Cox : Removed wake_up calls * Alan Cox : Use ttl/tos * Alan Cox : Cleaned up old debugging * Alan Cox : Use new kernel side addresses * Arnt Gulbrandsen : Fixed MSG_DONTROUTE in raw sockets. * Alan Cox : BSD style RAW socket demultiplexing. * Alan Cox : Beginnings of mrouted support. * Alan Cox : Added IP_HDRINCL option. * Alan Cox : Skip broadcast check if BSDism set. * David S. Miller : New socket lookup architecture. * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_IP_MROUTE struct sock *mroute_socket=NULL; #endif struct sock *raw_v4_htable[RAWV4_HTABLE_SIZE]; static void raw_v4_hash(struct sock *sk) { struct sock **skp = &raw_v4_htable[sk->num & (RAWV4_HTABLE_SIZE - 1)]; SOCKHASH_LOCK(); if ((sk->next = *skp) != NULL) (*skp)->pprev = &sk->next; *skp = sk; sk->pprev = skp; SOCKHASH_UNLOCK(); } static void raw_v4_unhash(struct sock *sk) { SOCKHASH_LOCK(); if (sk->pprev) { if (sk->next) sk->next->pprev = sk->pprev; *sk->pprev = sk->next; sk->pprev = NULL; } SOCKHASH_UNLOCK(); } /* Grumble... icmp and ip_input want to get at this... */ struct sock *raw_v4_lookup(struct sock *sk, unsigned short num, unsigned long raddr, unsigned long laddr, int dif) { struct sock *s = sk; SOCKHASH_LOCK(); for(s = sk; s; s = s->next) { if((s->num == num) && !(s->dead && (s->state == TCP_CLOSE)) && !(s->daddr && s->daddr != raddr) && !(s->rcv_saddr && s->rcv_saddr != laddr) && !(s->bound_dev_if && s->bound_dev_if != dif)) break; /* gotcha */ } SOCKHASH_UNLOCK(); return s; } void raw_err (struct sock *sk, struct sk_buff *skb) { int type = skb->h.icmph->type; int code = skb->h.icmph->code; u32 info = 0; int err = 0; int harderr = 0; /* Report error on raw socket, if: 1. User requested ip_recverr. 2. Socket is connected (otherwise the error indication is useless without ip_recverr and error is hard. */ if (!sk->ip_recverr && sk->state != TCP_ESTABLISHED) return; switch (type) { default: case ICMP_TIME_EXCEEDED: err = EHOSTUNREACH; break; case ICMP_SOURCE_QUENCH: return; case ICMP_PARAMETERPROB: err = EPROTO; info = ntohl(skb->h.icmph->un.gateway)>>24; harderr = 1; break; case ICMP_DEST_UNREACH: err = EHOSTUNREACH; if (code > NR_ICMP_UNREACH) break; err = icmp_err_convert[code].errno; harderr = icmp_err_convert[code].fatal; if (code == ICMP_FRAG_NEEDED) { harderr = (sk->ip_pmtudisc != IP_PMTUDISC_DONT); err = EMSGSIZE; info = ntohs(skb->h.icmph->un.frag.mtu); } } if (sk->ip_recverr) ip_icmp_error(sk, skb, err, 0, info, (u8 *)(skb->h.icmph + 1)); if (sk->ip_recverr || harderr) { sk->err = err; sk->error_report(sk); } } static int raw_rcv_skb(struct sock * sk, struct sk_buff * skb) { /* Charge it to the socket. */ if (sock_queue_rcv_skb(sk,skb)<0) { ip_statistics.IpInDiscards++; kfree_skb(skb); return -1; } ip_statistics.IpInDelivers++; return 0; } /* * This should be the easiest of all, all we do is * copy it into a buffer. All demultiplexing is done * in ip.c */ int raw_rcv(struct sock *sk, struct sk_buff *skb) { /* Now we need to copy this into memory. */ skb_trim(skb, ntohs(skb->nh.iph->tot_len)); skb->h.raw = skb->nh.raw; raw_rcv_skb(sk, skb); return 0; } struct rawfakehdr { struct iovec *iov; u32 saddr; }; /* * Send a RAW IP packet. */ /* * Callback support is trivial for SOCK_RAW */ static int raw_getfrag(const void *p, char *to, unsigned int offset, unsigned int fraglen) { struct rawfakehdr *rfh = (struct rawfakehdr *) p; return memcpy_fromiovecend(to, rfh->iov, offset, fraglen); } /* * IPPROTO_RAW needs extra work. */ static int raw_getrawfrag(const void *p, char *to, unsigned int offset, unsigned int fraglen) { struct rawfakehdr *rfh = (struct rawfakehdr *) p; if (memcpy_fromiovecend(to, rfh->iov, offset, fraglen)) return -EFAULT; if (offset==0) { struct iphdr *iph = (struct iphdr *)to; if (!iph->saddr) iph->saddr = rfh->saddr; iph->check=0; iph->tot_len=htons(fraglen); /* This is right as you can't frag RAW packets */ /* * Deliberate breach of modularity to keep * ip_build_xmit clean (well less messy). */ if (!iph->id) iph->id = htons(ip_id_count++); iph->check=ip_fast_csum((unsigned char *)iph, iph->ihl); } return 0; } static int raw_sendmsg(struct sock *sk, struct msghdr *msg, int len) { struct ipcm_cookie ipc; struct rawfakehdr rfh; struct rtable *rt = NULL; int free = 0; u32 daddr; u8 tos; int err; /* This check is ONLY to check for arithmetic overflow on integer(!) len. Not more! Real check will be made in ip_build_xmit --ANK BTW socket.c -> af_*.c -> ... make multiple invalid conversions size_t -> int. We MUST repair it f.e. by replacing all of them with size_t and revise all the places sort of len += sizeof(struct iphdr) If len was ULONG_MAX-10 it would be cathastrophe --ANK */ if (len < 0 || len > 0xFFFF) return -EMSGSIZE; /* * Check the flags. */ if (msg->msg_flags & MSG_OOB) /* Mirror BSD error message compatibility */ return -EOPNOTSUPP; if (msg->msg_flags & ~(MSG_DONTROUTE|MSG_DONTWAIT)) return(-EINVAL); /* * Get and verify the address. */ if (msg->msg_namelen) { struct sockaddr_in *usin = (struct sockaddr_in*)msg->msg_name; if (msg->msg_namelen < sizeof(*usin)) return(-EINVAL); if (usin->sin_family != AF_INET) { static int complained; if (!complained++) printk(KERN_INFO "%s forgot to set AF_INET in raw sendmsg. Fix it!\n", current->comm); if (usin->sin_family) return -EINVAL; } daddr = usin->sin_addr.s_addr; /* ANK: I did not forget to get protocol from port field. * I just do not know, who uses this weirdness. * IP_HDRINCL is much more convenient. */ } else { if (sk->state != TCP_ESTABLISHED) return(-EINVAL); daddr = sk->daddr; } ipc.addr = sk->saddr; ipc.opt = NULL; ipc.oif = sk->bound_dev_if; if (msg->msg_controllen) { int tmp = ip_cmsg_send(msg, &ipc); if (tmp) return tmp; if (ipc.opt) free=1; } rfh.saddr = ipc.addr; ipc.addr = daddr; if (!ipc.opt) ipc.opt = sk->opt; if (ipc.opt) { err = -EINVAL; /* Linux does not mangle headers on raw sockets, * so that IP options + IP_HDRINCL is non-sense. */ if (sk->ip_hdrincl) goto done; if (ipc.opt->srr) { if (!daddr) goto done; daddr = ipc.opt->faddr; } } tos = RT_TOS(sk->ip_tos) | sk->localroute; if (msg->msg_flags&MSG_DONTROUTE) tos |= RTO_ONLINK; if (MULTICAST(daddr)) { if (!ipc.oif) ipc.oif = sk->ip_mc_index; if (!rfh.saddr) rfh.saddr = sk->ip_mc_addr; } err = ip_route_output(&rt, daddr, rfh.saddr, tos, ipc.oif); if (err) goto done; err = -EACCES; if (rt->rt_flags&RTCF_BROADCAST && !sk->broadcast) goto done; rfh.iov = msg->msg_iov; rfh.saddr = rt->rt_src; if (!ipc.addr) ipc.addr = rt->rt_dst; err=ip_build_xmit(sk, sk->ip_hdrincl ? raw_getrawfrag : raw_getfrag, &rfh, len, &ipc, rt, msg->msg_flags); done: if (free) kfree(ipc.opt); ip_rt_put(rt); return err<0 ? err : len; } static void raw_close(struct sock *sk, long timeout) { /* Observation: when raw_close is called, processes have no access to socket anymore. But net still has. Step one, detach it from networking: A. Remove from hash tables. */ sk->state = TCP_CLOSE; raw_v4_unhash(sk); /* B. Raw sockets may have direct kernel references. Kill them. */ ip_ra_control(sk, 0, NULL); /* In this point socket cannot receive new packets anymore */ /* But we still have packets pending on receive queue and probably, our own packets waiting in device queues. sock_destroy will drain receive queue, but transmitted packets will delay socket destruction. Set sk->dead=1 in order to prevent wakeups, when these packet will be freed. */ sk->dead=1; destroy_sock(sk); /* That's all. No races here. */ } /* This gets rid of all the nasties in af_inet. -DaveM */ static int raw_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) { struct sockaddr_in *addr = (struct sockaddr_in *) uaddr; int chk_addr_ret; if((sk->state != TCP_CLOSE) || (addr_len < sizeof(struct sockaddr_in))) return -EINVAL; chk_addr_ret = inet_addr_type(addr->sin_addr.s_addr); if(addr->sin_addr.s_addr != 0 && chk_addr_ret != RTN_LOCAL && chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST) { #ifdef CONFIG_IP_TRANSPARENT_PROXY /* Superuser may bind to any address to allow transparent proxying. */ if(chk_addr_ret != RTN_UNICAST || !capable(CAP_NET_ADMIN)) #endif return -EADDRNOTAVAIL; } sk->rcv_saddr = sk->saddr = addr->sin_addr.s_addr; if(chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST) sk->saddr = 0; /* Use device */ dst_release(xchg(&sk->dst_cache, NULL)); return 0; } /* * This should be easy, if there is something there * we return it, otherwise we block. */ int raw_recvmsg(struct sock *sk, struct msghdr *msg, int len, int noblock, int flags,int *addr_len) { int copied=0; struct sk_buff *skb; int err; struct sockaddr_in *sin=(struct sockaddr_in *)msg->msg_name; if (flags & MSG_OOB) return -EOPNOTSUPP; if (addr_len) *addr_len=sizeof(*sin); if (flags & MSG_ERRQUEUE) return ip_recv_error(sk, msg, len); skb=skb_recv_datagram(sk,flags,noblock,&err); if(skb==NULL) return err; copied = skb->len; if (len < copied) { msg->msg_flags |= MSG_TRUNC; copied = len; } err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); if (err) goto done; sk->stamp=skb->stamp; /* Copy the address. */ if (sin) { sin->sin_family = AF_INET; sin->sin_addr.s_addr = skb->nh.iph->saddr; } if (sk->ip_cmsg_flags) ip_cmsg_recv(msg, skb); done: skb_free_datagram(sk, skb); return (err ? : copied); } static int raw_init(struct sock *sk) { struct raw_opt *tp = &(sk->tp_pinfo.tp_raw4); if (sk->num == IPPROTO_ICMP) memset(&tp->filter, 0, sizeof(tp->filter)); return 0; } static int raw_seticmpfilter(struct sock *sk, char *optval, int optlen) { if (optlen > sizeof(struct icmp_filter)) optlen = sizeof(struct icmp_filter); if (copy_from_user(&sk->tp_pinfo.tp_raw4.filter, optval, optlen)) return -EFAULT; return 0; } static int raw_geticmpfilter(struct sock *sk, char *optval, int *optlen) { int len; if (get_user(len,optlen)) return -EFAULT; if (len > sizeof(struct icmp_filter)) len = sizeof(struct icmp_filter); if (put_user(len, optlen)) return -EFAULT; if (copy_to_user(optval, &sk->tp_pinfo.tp_raw4.filter, len)) return -EFAULT; return 0; } static int raw_setsockopt(struct sock *sk, int level, int optname, char *optval, int optlen) { if (level != SOL_RAW) return ip_setsockopt(sk, level, optname, optval, optlen); switch (optname) { case ICMP_FILTER: if (sk->num != IPPROTO_ICMP) return -EOPNOTSUPP; return raw_seticmpfilter(sk, optval, optlen); }; return -ENOPROTOOPT; } static int raw_getsockopt(struct sock *sk, int level, int optname, char *optval, int *optlen) { if (level != SOL_RAW) return ip_getsockopt(sk, level, optname, optval, optlen); switch (optname) { case ICMP_FILTER: if (sk->num != IPPROTO_ICMP) return -EOPNOTSUPP; return raw_geticmpfilter(sk, optval, optlen); }; return -ENOPROTOOPT; } struct proto raw_prot = { (struct sock *)&raw_prot, /* sklist_next */ (struct sock *)&raw_prot, /* sklist_prev */ raw_close, /* close */ udp_connect, /* connect */ NULL, /* accept */ NULL, /* retransmit */ NULL, /* write_wakeup */ NULL, /* read_wakeup */ datagram_poll, /* poll */ #ifdef CONFIG_IP_MROUTE ipmr_ioctl, /* ioctl */ #else NULL, /* ioctl */ #endif raw_init, /* init */ NULL, /* destroy */ NULL, /* shutdown */ raw_setsockopt, /* setsockopt */ raw_getsockopt, /* getsockopt */ raw_sendmsg, /* sendmsg */ raw_recvmsg, /* recvmsg */ raw_bind, /* bind */ raw_rcv_skb, /* backlog_rcv */ raw_v4_hash, /* hash */ raw_v4_unhash, /* unhash */ NULL, /* get_port */ 128, /* max_header */ 0, /* retransmits */ "RAW", /* name */ 0, /* inuse */ 0 /* highestinuse */ };