/* * 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. * * The Internet Protocol (IP) module. * * Version: @(#)ip.c 1.0.16b 9/1/93 * * Authors: Ross Biro, * Fred N. van Kempen, * Donald Becker, * Alan Cox, * Richard Underwood * Stefan Becker, * * * Fixes: * Alan Cox : Commented a couple of minor bits of surplus code * Alan Cox : Undefining IP_FORWARD doesn't include the code * (just stops a compiler warning). * Alan Cox : Frames with >=MAX_ROUTE record routes, strict routes or loose routes * are junked rather than corrupting things. * Alan Cox : Frames to bad broadcast subnets are dumped * We used to process them non broadcast and * boy could that cause havoc. * Alan Cox : ip_forward sets the free flag on the * new frame it queues. Still crap because * it copies the frame but at least it * doesn't eat memory too. * Alan Cox : Generic queue code and memory fixes. * Fred Van Kempen : IP fragment support (borrowed from NET2E) * Gerhard Koerting: Forward fragmented frames correctly. * Gerhard Koerting: Fixes to my fix of the above 8-). * Gerhard Koerting: IP interface addressing fix. * Linus Torvalds : More robustness checks * Alan Cox : Even more checks: Still not as robust as it ought to be * Alan Cox : Save IP header pointer for later * Alan Cox : ip option setting * Alan Cox : Use ip_tos/ip_ttl settings * Alan Cox : Fragmentation bogosity removed * (Thanks to Mark.Bush@prg.ox.ac.uk) * Dmitry Gorodchanin : Send of a raw packet crash fix. * Alan Cox : Silly ip bug when an overlength * fragment turns up. Now frees the * queue. * Linus Torvalds/ : Memory leakage on fragmentation * Alan Cox : handling. * Gerhard Koerting: Forwarding uses IP priority hints * Teemu Rantanen : Fragment problems. * Alan Cox : General cleanup, comments and reformat * Alan Cox : SNMP statistics * Alan Cox : BSD address rule semantics. Also see * UDP as there is a nasty checksum issue * if you do things the wrong way. * Alan Cox : Always defrag, moved IP_FORWARD to the config.in file * Alan Cox : IP options adjust sk->priority. * Pedro Roque : Fix mtu/length error in ip_forward. * Alan Cox : Avoid ip_chk_addr when possible. * Richard Underwood : IP multicasting. * Alan Cox : Cleaned up multicast handlers. * Alan Cox : RAW sockets demultiplex in the BSD style. * Gunther Mayer : Fix the SNMP reporting typo * Alan Cox : Always in group 224.0.0.1 * Alan Cox : Multicast loopback error for 224.0.0.1 * Alan Cox : IP_MULTICAST_LOOP option. * Alan Cox : Use notifiers. * Bjorn Ekwall : Removed ip_csum (from slhc.c too) * Bjorn Ekwall : Moved ip_fast_csum to ip.h (inline!) * Stefan Becker : Send out ICMP HOST REDIRECT * Alan Cox : Only send ICMP_REDIRECT if src/dest are the same net. * * * To Fix: * IP option processing is mostly not needed. ip_forward needs to know about routing rules * and time stamp but that's about all. Use the route mtu field here too * IP fragmentation wants rewriting cleanly. The RFC815 algorithm is much more efficient * and could be made very efficient with the addition of some virtual memory hacks to permit * the allocation of a buffer that can then be 'grown' by twiddling page tables. * Output fragmentation wants updating along with the buffer management to use a single * interleaved copy algorithm so that fragmenting has a one copy overhead. Actual packet * output should probably do its own fragmentation at the UDP/RAW layer. TCP shouldn't cause * fragmentation anyway. * * 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 "snmp.h" #include "ip.h" #include "protocol.h" #include "route.h" #include "tcp.h" #include "udp.h" #include #include "sock.h" #include "arp.h" #include "icmp.h" #include "raw.h" #include #include #define CONFIG_IP_DEFRAG extern int last_retran; extern void sort_send(struct sock *sk); #define min(a,b) ((a)<(b)?(a):(b)) #define LOOPBACK(x) (((x) & htonl(0xff000000)) == htonl(0x7f000000)) /* * SNMP management statistics */ #ifdef CONFIG_IP_FORWARD struct ip_mib ip_statistics={1,64,}; /* Forwarding=Yes, Default TTL=64 */ #else struct ip_mib ip_statistics={0,64,}; /* Forwarding=No, Default TTL=64 */ #endif /* * Handle the issuing of an ioctl() request * for the ip device. This is scheduled to * disappear */ int ip_ioctl(struct sock *sk, int cmd, unsigned long arg) { switch(cmd) { default: return(-EINVAL); } } /* these two routines will do routing. */ static void strict_route(struct iphdr *iph, struct options *opt) { } static void loose_route(struct iphdr *iph, struct options *opt) { } /* This routine will check to see if we have lost a gateway. */ void ip_route_check(unsigned long daddr) { } #if 0 /* this routine puts the options at the end of an ip header. */ static int build_options(struct iphdr *iph, struct options *opt) { unsigned char *ptr; /* currently we don't support any options. */ ptr = (unsigned char *)(iph+1); *ptr = 0; return (4); } #endif /* * Take an skb, and fill in the MAC header. */ static int ip_send(struct sk_buff *skb, unsigned long daddr, int len, struct device *dev, unsigned long saddr) { int mac = 0; skb->dev = dev; skb->arp = 1; if (dev->hard_header) { /* * Build a hardware header. Source address is our mac, destination unknown * (rebuild header will sort this out) */ mac = dev->hard_header(skb->data, dev, ETH_P_IP, NULL, NULL, len, skb); if (mac < 0) { mac = -mac; skb->arp = 0; skb->raddr = daddr; /* next routing address */ } } return mac; } int ip_id_count = 0; /* * This routine builds the appropriate hardware/IP headers for * the routine. It assumes that if *dev != NULL then the * protocol knows what it's doing, otherwise it uses the * routing/ARP tables to select a device struct. */ int ip_build_header(struct sk_buff *skb, unsigned long saddr, unsigned long daddr, struct device **dev, int type, struct options *opt, int len, int tos, int ttl) { static struct options optmem; struct iphdr *iph; struct rtable *rt; unsigned char *buff; unsigned long raddr; int tmp; unsigned long src; buff = skb->data; /* * See if we need to look up the device. */ #ifdef CONFIG_INET_MULTICAST if(MULTICAST(daddr) && *dev==NULL && skb->sk && *skb->sk->ip_mc_name) *dev=dev_get(skb->sk->ip_mc_name); #endif if (*dev == NULL) { if(skb->localroute) rt = ip_rt_local(daddr, &optmem, &src); else rt = ip_rt_route(daddr, &optmem, &src); if (rt == NULL) { ip_statistics.IpOutNoRoutes++; return(-ENETUNREACH); } *dev = rt->rt_dev; /* * If the frame is from us and going off machine it MUST MUST MUST * have the output device ip address and never the loopback */ if (LOOPBACK(saddr) && !LOOPBACK(daddr)) saddr = src;/*rt->rt_dev->pa_addr;*/ raddr = rt->rt_gateway; opt = &optmem; } else { /* * We still need the address of the first hop. */ if(skb->localroute) rt = ip_rt_local(daddr, &optmem, &src); else rt = ip_rt_route(daddr, &optmem, &src); /* * If the frame is from us and going off machine it MUST MUST MUST * have the output device ip address and never the loopback */ if (LOOPBACK(saddr) && !LOOPBACK(daddr)) saddr = src;/*rt->rt_dev->pa_addr;*/ raddr = (rt == NULL) ? 0 : rt->rt_gateway; } /* * No source addr so make it our addr */ if (saddr == 0) saddr = src; /* * No gateway so aim at the real destination */ if (raddr == 0) raddr = daddr; /* * Now build the MAC header. */ tmp = ip_send(skb, raddr, len, *dev, saddr); buff += tmp; len -= tmp; /* * Book keeping */ skb->dev = *dev; skb->saddr = saddr; if (skb->sk) skb->sk->saddr = saddr; /* * Now build the IP header. */ /* * If we are using IPPROTO_RAW, then we don't need an IP header, since * one is being supplied to us by the user */ if(type == IPPROTO_RAW) return (tmp); iph = (struct iphdr *)buff; iph->version = 4; iph->tos = tos; iph->frag_off = 0; iph->ttl = ttl; iph->daddr = daddr; iph->saddr = saddr; iph->protocol = type; iph->ihl = 5; skb->ip_hdr = iph; /* Setup the IP options. */ #ifdef Not_Yet_Avail build_options(iph, opt); #endif return(20 + tmp); /* IP header plus MAC header size */ } static int do_options(struct iphdr *iph, struct options *opt) { unsigned char *buff; int done = 0; int i, len = sizeof(struct iphdr); /* Zero out the options. */ opt->record_route.route_size = 0; opt->loose_route.route_size = 0; opt->strict_route.route_size = 0; opt->tstamp.ptr = 0; opt->security = 0; opt->compartment = 0; opt->handling = 0; opt->stream = 0; opt->tcc = 0; return(0); /* Advance the pointer to start at the options. */ buff = (unsigned char *)(iph + 1); /* Now start the processing. */ while (!done && len < iph->ihl*4) switch(*buff) { case IPOPT_END: done = 1; break; case IPOPT_NOOP: buff++; len++; break; case IPOPT_SEC: buff++; if (*buff != 11) return(1); buff++; opt->security = ntohs(*(unsigned short *)buff); buff += 2; opt->compartment = ntohs(*(unsigned short *)buff); buff += 2; opt->handling = ntohs(*(unsigned short *)buff); buff += 2; opt->tcc = ((*buff) << 16) + ntohs(*(unsigned short *)(buff+1)); buff += 3; len += 11; break; case IPOPT_LSRR: buff++; if ((*buff - 3)% 4 != 0) return(1); len += *buff; opt->loose_route.route_size = (*buff -3)/4; buff++; if (*buff % 4 != 0) return(1); opt->loose_route.pointer = *buff/4 - 1; buff++; buff++; for (i = 0; i < opt->loose_route.route_size; i++) { if(i>=MAX_ROUTE) return(1); opt->loose_route.route[i] = *(unsigned long *)buff; buff += 4; } break; case IPOPT_SSRR: buff++; if ((*buff - 3)% 4 != 0) return(1); len += *buff; opt->strict_route.route_size = (*buff -3)/4; buff++; if (*buff % 4 != 0) return(1); opt->strict_route.pointer = *buff/4 - 1; buff++; buff++; for (i = 0; i < opt->strict_route.route_size; i++) { if(i>=MAX_ROUTE) return(1); opt->strict_route.route[i] = *(unsigned long *)buff; buff += 4; } break; case IPOPT_RR: buff++; if ((*buff - 3)% 4 != 0) return(1); len += *buff; opt->record_route.route_size = (*buff -3)/4; buff++; if (*buff % 4 != 0) return(1); opt->record_route.pointer = *buff/4 - 1; buff++; buff++; for (i = 0; i < opt->record_route.route_size; i++) { if(i>=MAX_ROUTE) return 1; opt->record_route.route[i] = *(unsigned long *)buff; buff += 4; } break; case IPOPT_SID: len += 4; buff +=2; opt->stream = *(unsigned short *)buff; buff += 2; break; case IPOPT_TIMESTAMP: buff++; len += *buff; if (*buff % 4 != 0) return(1); opt->tstamp.len = *buff / 4 - 1; buff++; if ((*buff - 1) % 4 != 0) return(1); opt->tstamp.ptr = (*buff-1)/4; buff++; opt->tstamp.x.full_char = *buff; buff++; for (i = 0; i < opt->tstamp.len; i++) { opt->tstamp.data[i] = *(unsigned long *)buff; buff += 4; } break; default: return(1); } if (opt->record_route.route_size == 0) { if (opt->strict_route.route_size != 0) { memcpy(&(opt->record_route), &(opt->strict_route), sizeof(opt->record_route)); } else if (opt->loose_route.route_size != 0) { memcpy(&(opt->record_route), &(opt->loose_route), sizeof(opt->record_route)); } } if (opt->strict_route.route_size != 0 && opt->strict_route.route_size != opt->strict_route.pointer) { strict_route(iph, opt); return(0); } if (opt->loose_route.route_size != 0 && opt->loose_route.route_size != opt->loose_route.pointer) { loose_route(iph, opt); return(0); } return(0); } /* * This routine does all the checksum computations that don't * require anything special (like copying or special headers). */ unsigned short ip_compute_csum(unsigned char * buff, int len) { unsigned long sum = 0; /* Do the first multiple of 4 bytes and convert to 16 bits. */ if (len > 3) { __asm__("clc\n" "1:\t" "lodsl\n\t" "adcl %%eax, %%ebx\n\t" "loop 1b\n\t" "adcl $0, %%ebx\n\t" "movl %%ebx, %%eax\n\t" "shrl $16, %%eax\n\t" "addw %%ax, %%bx\n\t" "adcw $0, %%bx" : "=b" (sum) , "=S" (buff) : "0" (sum), "c" (len >> 2) ,"1" (buff) : "ax", "cx", "si", "bx" ); } if (len & 2) { __asm__("lodsw\n\t" "addw %%ax, %%bx\n\t" "adcw $0, %%bx" : "=b" (sum), "=S" (buff) : "0" (sum), "1" (buff) : "bx", "ax", "si"); } if (len & 1) { __asm__("lodsb\n\t" "movb $0, %%ah\n\t" "addw %%ax, %%bx\n\t" "adcw $0, %%bx" : "=b" (sum), "=S" (buff) : "0" (sum), "1" (buff) : "bx", "ax", "si"); } sum =~sum; return(sum & 0xffff); } /* * Generate a checksum for an outgoing IP datagram. */ void ip_send_check(struct iphdr *iph) { iph->check = 0; iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); } /************************ Fragment Handlers From NET2E **********************************/ /* * This fragment handler is a bit of a heap. On the other hand it works quite * happily and handles things quite well. */ static struct ipq *ipqueue = NULL; /* IP fragment queue */ /* * Create a new fragment entry. */ static struct ipfrag *ip_frag_create(int offset, int end, struct sk_buff *skb, unsigned char *ptr) { struct ipfrag *fp; fp = (struct ipfrag *) kmalloc(sizeof(struct ipfrag), GFP_ATOMIC); if (fp == NULL) { printk("IP: frag_create: no memory left !\n"); return(NULL); } memset(fp, 0, sizeof(struct ipfrag)); /* Fill in the structure. */ fp->offset = offset; fp->end = end; fp->len = end - offset; fp->skb = skb; fp->ptr = ptr; return(fp); } /* * Find the correct entry in the "incomplete datagrams" queue for * this IP datagram, and return the queue entry address if found. */ static struct ipq *ip_find(struct iphdr *iph) { struct ipq *qp; struct ipq *qplast; cli(); qplast = NULL; for(qp = ipqueue; qp != NULL; qplast = qp, qp = qp->next) { if (iph->id== qp->iph->id && iph->saddr == qp->iph->saddr && iph->daddr == qp->iph->daddr && iph->protocol == qp->iph->protocol) { del_timer(&qp->timer); /* So it doesn't vanish on us. The timer will be reset anyway */ sti(); return(qp); } } sti(); return(NULL); } /* * Remove an entry from the "incomplete datagrams" queue, either * because we completed, reassembled and processed it, or because * it timed out. */ static void ip_free(struct ipq *qp) { struct ipfrag *fp; struct ipfrag *xp; /* * Stop the timer for this entry. */ del_timer(&qp->timer); /* Remove this entry from the "incomplete datagrams" queue. */ cli(); if (qp->prev == NULL) { ipqueue = qp->next; if (ipqueue != NULL) ipqueue->prev = NULL; } else { qp->prev->next = qp->next; if (qp->next != NULL) qp->next->prev = qp->prev; } /* Release all fragment data. */ fp = qp->fragments; while (fp != NULL) { xp = fp->next; IS_SKB(fp->skb); kfree_skb(fp->skb,FREE_READ); kfree_s(fp, sizeof(struct ipfrag)); fp = xp; } /* Release the MAC header. */ kfree_s(qp->mac, qp->maclen); /* Release the IP header. */ kfree_s(qp->iph, qp->ihlen + 8); /* Finally, release the queue descriptor itself. */ kfree_s(qp, sizeof(struct ipq)); sti(); } /* * Oops- a fragment queue timed out. Kill it and send an ICMP reply. */ static void ip_expire(unsigned long arg) { struct ipq *qp; qp = (struct ipq *)arg; /* * Send an ICMP "Fragment Reassembly Timeout" message. */ ip_statistics.IpReasmTimeout++; ip_statistics.IpReasmFails++; /* This if is always true... shrug */ if(qp->fragments!=NULL) icmp_send(qp->fragments->skb,ICMP_TIME_EXCEEDED, ICMP_EXC_FRAGTIME, 0, qp->dev); /* * Nuke the fragment queue. */ ip_free(qp); } /* * Add an entry to the 'ipq' queue for a newly received IP datagram. * We will (hopefully :-) receive all other fragments of this datagram * in time, so we just create a queue for this datagram, in which we * will insert the received fragments at their respective positions. */ static struct ipq *ip_create(struct sk_buff *skb, struct iphdr *iph, struct device *dev) { struct ipq *qp; int maclen; int ihlen; qp = (struct ipq *) kmalloc(sizeof(struct ipq), GFP_ATOMIC); if (qp == NULL) { printk("IP: create: no memory left !\n"); return(NULL); skb->dev = qp->dev; } memset(qp, 0, sizeof(struct ipq)); /* * Allocate memory for the MAC header. * * FIXME: We have a maximum MAC address size limit and define * elsewhere. We should use it here and avoid the 3 kmalloc() calls */ maclen = ((unsigned long) iph) - ((unsigned long) skb->data); qp->mac = (unsigned char *) kmalloc(maclen, GFP_ATOMIC); if (qp->mac == NULL) { printk("IP: create: no memory left !\n"); kfree_s(qp, sizeof(struct ipq)); return(NULL); } /* * Allocate memory for the IP header (plus 8 octets for ICMP). */ ihlen = (iph->ihl * sizeof(unsigned long)); qp->iph = (struct iphdr *) kmalloc(ihlen + 8, GFP_ATOMIC); if (qp->iph == NULL) { printk("IP: create: no memory left !\n"); kfree_s(qp->mac, maclen); kfree_s(qp, sizeof(struct ipq)); return(NULL); } /* Fill in the structure. */ memcpy(qp->mac, skb->data, maclen); memcpy(qp->iph, iph, ihlen + 8); qp->len = 0; qp->ihlen = ihlen; qp->maclen = maclen; qp->fragments = NULL; qp->dev = dev; /* Start a timer for this entry. */ qp->timer.expires = IP_FRAG_TIME; /* about 30 seconds */ qp->timer.data = (unsigned long) qp; /* pointer to queue */ qp->timer.function = ip_expire; /* expire function */ add_timer(&qp->timer); /* Add this entry to the queue. */ qp->prev = NULL; cli(); qp->next = ipqueue; if (qp->next != NULL) qp->next->prev = qp; ipqueue = qp; sti(); return(qp); } /* * See if a fragment queue is complete. */ static int ip_done(struct ipq *qp) { struct ipfrag *fp; int offset; /* Only possible if we received the final fragment. */ if (qp->len == 0) return(0); /* Check all fragment offsets to see if they connect. */ fp = qp->fragments; offset = 0; while (fp != NULL) { if (fp->offset > offset) return(0); /* fragment(s) missing */ offset = fp->end; fp = fp->next; } /* All fragments are present. */ return(1); } /* * Build a new IP datagram from all its fragments. * * FIXME: We copy here because we lack an effective way of handling lists * of bits on input. Until the new skb data handling is in I'm not going * to touch this with a bargepole. This also causes a 4Kish limit on * packet sizes. */ static struct sk_buff *ip_glue(struct ipq *qp) { struct sk_buff *skb; struct iphdr *iph; struct ipfrag *fp; unsigned char *ptr; int count, len; /* * Allocate a new buffer for the datagram. */ len = qp->maclen + qp->ihlen + qp->len; if ((skb = alloc_skb(len,GFP_ATOMIC)) == NULL) { ip_statistics.IpReasmFails++; printk("IP: queue_glue: no memory for gluing queue 0x%X\n", (int) qp); ip_free(qp); return(NULL); } /* Fill in the basic details. */ skb->len = (len - qp->maclen); skb->h.raw = skb->data; skb->free = 1; /* Copy the original MAC and IP headers into the new buffer. */ ptr = (unsigned char *) skb->h.raw; memcpy(ptr, ((unsigned char *) qp->mac), qp->maclen); ptr += qp->maclen; memcpy(ptr, ((unsigned char *) qp->iph), qp->ihlen); ptr += qp->ihlen; skb->h.raw += qp->maclen; count = 0; /* Copy the data portions of all fragments into the new buffer. */ fp = qp->fragments; while(fp != NULL) { if(count+fp->len > skb->len) { printk("Invalid fragment list: Fragment over size.\n"); ip_free(qp); kfree_skb(skb,FREE_WRITE); ip_statistics.IpReasmFails++; return NULL; } memcpy((ptr + fp->offset), fp->ptr, fp->len); count += fp->len; fp = fp->next; } /* We glued together all fragments, so remove the queue entry. */ ip_free(qp); /* Done with all fragments. Fixup the new IP header. */ iph = skb->h.iph; iph->frag_off = 0; iph->tot_len = htons((iph->ihl * sizeof(unsigned long)) + count); skb->ip_hdr = iph; ip_statistics.IpReasmOKs++; return(skb); } /* * Process an incoming IP datagram fragment. */ static struct sk_buff *ip_defrag(struct iphdr *iph, struct sk_buff *skb, struct device *dev) { struct ipfrag *prev, *next; struct ipfrag *tfp; struct ipq *qp; struct sk_buff *skb2; unsigned char *ptr; int flags, offset; int i, ihl, end; ip_statistics.IpReasmReqds++; /* Find the entry of this IP datagram in the "incomplete datagrams" queue. */ qp = ip_find(iph); /* Is this a non-fragmented datagram? */ offset = ntohs(iph->frag_off); flags = offset & ~IP_OFFSET; offset &= IP_OFFSET; if (((flags & IP_MF) == 0) && (offset == 0)) { if (qp != NULL) ip_free(qp); /* Huh? How could this exist?? */ return(skb); } offset <<= 3; /* offset is in 8-byte chunks */ /* * If the queue already existed, keep restarting its timer as long * as we still are receiving fragments. Otherwise, create a fresh * queue entry. */ if (qp != NULL) { del_timer(&qp->timer); qp->timer.expires = IP_FRAG_TIME; /* about 30 seconds */ qp->timer.data = (unsigned long) qp; /* pointer to queue */ qp->timer.function = ip_expire; /* expire function */ add_timer(&qp->timer); } else { /* * If we failed to create it, then discard the frame */ if ((qp = ip_create(skb, iph, dev)) == NULL) { skb->sk = NULL; kfree_skb(skb, FREE_READ); ip_statistics.IpReasmFails++; return NULL; } } /* * Determine the position of this fragment. */ ihl = (iph->ihl * sizeof(unsigned long)); end = offset + ntohs(iph->tot_len) - ihl; /* * Point into the IP datagram 'data' part. */ ptr = skb->data + dev->hard_header_len + ihl; /* * Is this the final fragment? */ if ((flags & IP_MF) == 0) qp->len = end; /* * Find out which fragments are in front and at the back of us * in the chain of fragments so far. We must know where to put * this fragment, right? */ prev = NULL; for(next = qp->fragments; next != NULL; next = next->next) { if (next->offset > offset) break; /* bingo! */ prev = next; } /* * We found where to put this one. * Check for overlap with preceding fragment, and, if needed, * align things so that any overlaps are eliminated. */ if (prev != NULL && offset < prev->end) { i = prev->end - offset; offset += i; /* ptr into datagram */ ptr += i; /* ptr into fragment data */ } /* * Look for overlap with succeeding segments. * If we can merge fragments, do it. */ for(; next != NULL; next = tfp) { tfp = next->next; if (next->offset >= end) break; /* no overlaps at all */ i = end - next->offset; /* overlap is 'i' bytes */ next->len -= i; /* so reduce size of */ next->offset += i; /* next fragment */ next->ptr += i; /* * If we get a frag size of <= 0, remove it and the packet * that it goes with. */ if (next->len <= 0) { if (next->prev != NULL) next->prev->next = next->next; else qp->fragments = next->next; if (tfp->next != NULL) next->next->prev = next->prev; kfree_skb(next->skb,FREE_READ); kfree_s(next, sizeof(struct ipfrag)); } } /* * Insert this fragment in the chain of fragments. */ tfp = NULL; tfp = ip_frag_create(offset, end, skb, ptr); /* * No memory to save the fragment - so throw the lot */ if (!tfp) { skb->sk = NULL; kfree_skb(skb, FREE_READ); return NULL; } tfp->prev = prev; tfp->next = next; if (prev != NULL) prev->next = tfp; else qp->fragments = tfp; if (next != NULL) next->prev = tfp; /* * OK, so we inserted this new fragment into the chain. * Check if we now have a full IP datagram which we can * bump up to the IP layer... */ if (ip_done(qp)) { skb2 = ip_glue(qp); /* glue together the fragments */ return(skb2); } return(NULL); } /* * This IP datagram is too large to be sent in one piece. Break it up into * smaller pieces (each of size equal to the MAC header plus IP header plus * a block of the data of the original IP data part) that will yet fit in a * single device frame, and queue such a frame for sending by calling the * ip_queue_xmit(). Note that this is recursion, and bad things will happen * if this function causes a loop... * * Yes this is inefficient, feel free to submit a quicker one. * * **Protocol Violation** * We copy all the options to each fragment. !FIXME! */ void ip_fragment(struct sock *sk, struct sk_buff *skb, struct device *dev, int is_frag) { struct iphdr *iph; unsigned char *raw; unsigned char *ptr; struct sk_buff *skb2; int left, mtu, hlen, len; int offset; unsigned long flags; /* * Point into the IP datagram header. */ raw = skb->data; iph = (struct iphdr *) (raw + dev->hard_header_len); skb->ip_hdr = iph; /* * Setup starting values. */ hlen = (iph->ihl * sizeof(unsigned long)); left = ntohs(iph->tot_len) - hlen; /* Space per frame */ hlen += dev->hard_header_len; /* Total header size */ mtu = (dev->mtu - hlen); /* Size of data space */ ptr = (raw + hlen); /* Where to start from */ /* * Check for any "DF" flag. [DF means do not fragment] */ if (ntohs(iph->frag_off) & IP_DF) { /* * Reply giving the MTU of the failed hop. */ ip_statistics.IpFragFails++; icmp_send(skb,ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, dev->mtu, dev); return; } /* * The protocol doesn't seem to say what to do in the case that the * frame + options doesn't fit the mtu. As it used to fall down dead * in this case we were fortunate it didn't happen */ if(mtu<8) { /* It's wrong but it's better than nothing */ icmp_send(skb,ICMP_DEST_UNREACH,ICMP_FRAG_NEEDED,dev->mtu, dev); ip_statistics.IpFragFails++; return; } /* * Fragment the datagram. */ /* * The initial offset is 0 for a complete frame. When * fragmenting fragments it's wherever this one starts. */ if (is_frag & 2) offset = (ntohs(iph->frag_off) & 0x1fff) << 3; else offset = 0; /* * Keep copying data until we run out. */ while(left > 0) { len = left; /* IF: it doesn't fit, use 'mtu' - the data space left */ if (len > mtu) len = mtu; /* IF: we are not sending upto and including the packet end then align the next start on an eight byte boundary */ if (len < left) { len/=8; len*=8; } /* * Allocate buffer. */ if ((skb2 = alloc_skb(len + hlen,GFP_ATOMIC)) == NULL) { printk("IP: frag: no memory for new fragment!\n"); ip_statistics.IpFragFails++; return; } /* * Set up data on packet */ skb2->arp = skb->arp; if(skb->free==0) printk("IP fragmenter: BUG free!=1 in fragmenter\n"); skb2->free = 1; skb2->len = len + hlen; skb2->h.raw=(char *) skb2->data; /* * Charge the memory for the fragment to any owner * it might possess */ save_flags(flags); if (sk) { cli(); sk->wmem_alloc += skb2->mem_len; skb2->sk=sk; } restore_flags(flags); skb2->raddr = skb->raddr; /* For rebuild_header - must be here */ /* * Copy the packet header into the new buffer. */ memcpy(skb2->h.raw, raw, hlen); /* * Copy a block of the IP datagram. */ memcpy(skb2->h.raw + hlen, ptr, len); left -= len; skb2->h.raw+=dev->hard_header_len; /* * Fill in the new header fields. */ iph = (struct iphdr *)(skb2->h.raw/*+dev->hard_header_len*/); iph->frag_off = htons((offset >> 3)); /* * Added AC : If we are fragmenting a fragment thats not the * last fragment then keep MF on each bit */ if (left > 0 || (is_frag & 1)) iph->frag_off |= htons(IP_MF); ptr += len; offset += len; /* * Put this fragment into the sending queue. */ ip_statistics.IpFragCreates++; ip_queue_xmit(sk, dev, skb2, 2); } ip_statistics.IpFragOKs++; } #ifdef CONFIG_IP_FORWARD /* * Forward an IP datagram to its next destination. */ static void ip_forward(struct sk_buff *skb, struct device *dev, int is_frag) { struct device *dev2; /* Output device */ struct iphdr *iph; /* Our header */ struct sk_buff *skb2; /* Output packet */ struct rtable *rt; /* Route we use */ unsigned char *ptr; /* Data pointer */ unsigned long raddr; /* Router IP address */ /* * See if we are allowed to forward this. */ #ifdef CONFIG_IP_FIREWALL int err; if((err=ip_fw_chk(skb->h.iph, dev, ip_fw_fwd_chain, ip_fw_fwd_policy, 0))!=1) { if(err==-1) icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, dev); return; } #endif /* * According to the RFC, we must first decrease the TTL field. If * that reaches zero, we must reply an ICMP control message telling * that the packet's lifetime expired. * * Exception: * We may not generate an ICMP for an ICMP. icmp_send does the * enforcement of this so we can forget it here. It is however * sometimes VERY important. */ iph = skb->h.iph; iph->ttl--; if (iph->ttl <= 0) { /* Tell the sender its packet died... */ icmp_send(skb, ICMP_TIME_EXCEEDED, ICMP_EXC_TTL, 0, dev); return; } /* * Re-compute the IP header checksum. * This is inefficient. We know what has happened to the header * and could thus adjust the checksum as Phil Karn does in KA9Q */ ip_send_check(iph); /* * OK, the packet is still valid. Fetch its destination address, * and give it to the IP sender for further processing. */ rt = ip_rt_route(iph->daddr, NULL, NULL); if (rt == NULL) { /* * Tell the sender its packet cannot be delivered. Again * ICMP is screened later. */ icmp_send(skb, ICMP_DEST_UNREACH, ICMP_NET_UNREACH, 0, dev); return; } /* * Gosh. Not only is the packet valid; we even know how to * forward it onto its final destination. Can we say this * is being plain lucky? * If the router told us that there is no GW, use the dest. * IP address itself- we seem to be connected directly... */ raddr = rt->rt_gateway; if (raddr != 0) { /* * There is a gateway so find the correct route for it. * Gateways cannot in turn be gatewayed. */ rt = ip_rt_route(raddr, NULL, NULL); if (rt == NULL) { /* * Tell the sender its packet cannot be delivered... */ icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0, dev); return; } if (rt->rt_gateway != 0) raddr = rt->rt_gateway; } else raddr = iph->daddr; /* * Having picked a route we can now send the frame out. */ dev2 = rt->rt_dev; /* * In IP you never have to forward a frame on the interface that it * arrived upon. We now generate an ICMP HOST REDIRECT giving the route * we calculated. */ #ifdef CONFIG_IP_NO_ICMP_REDIRECT if (dev == dev2) return; #else if (dev == dev2 && (iph->saddr&dev->pa_mask) == (iph->daddr & dev->pa_mask)) icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, raddr, dev); #endif /* * We now allocate a new buffer, and copy the datagram into it. * If the indicated interface is up and running, kick it. */ if (dev2->flags & IFF_UP) { /* * Current design decrees we copy the packet. For identical header * lengths we could avoid it. The new skb code will let us push * data so the problem goes away then. */ skb2 = alloc_skb(dev2->hard_header_len + skb->len, GFP_ATOMIC); /* * This is rare and since IP is tolerant of network failures * quite harmless. */ if (skb2 == NULL) { printk("\nIP: No memory available for IP forward\n"); return; } ptr = skb2->data; skb2->free = 1; skb2->len = skb->len + dev2->hard_header_len; skb2->h.raw = ptr; /* * Copy the packet data into the new buffer. */ memcpy(ptr + dev2->hard_header_len, skb->h.raw, skb->len); /* Now build the MAC header. */ (void) ip_send(skb2, raddr, skb->len, dev2, dev2->pa_addr); ip_statistics.IpForwDatagrams++; /* * See if it needs fragmenting. Note in ip_rcv we tagged * the fragment type. This must be right so that * the fragmenter does the right thing. */ if(skb2->len > dev2->mtu + dev2->hard_header_len) { ip_fragment(NULL,skb2,dev2, is_frag); kfree_skb(skb2,FREE_WRITE); } else { #ifdef CONFIG_IP_ACCT /* * Count mapping we shortcut */ ip_acct_cnt(iph,dev,ip_acct_chain); #endif /* * Map service types to priority. We lie about * throughput being low priority, but it's a good * choice to help improve general usage. */ if(iph->tos & IPTOS_LOWDELAY) dev_queue_xmit(skb2, dev2, SOPRI_INTERACTIVE); else if(iph->tos & IPTOS_THROUGHPUT) dev_queue_xmit(skb2, dev2, SOPRI_BACKGROUND); else dev_queue_xmit(skb2, dev2, SOPRI_NORMAL); } } } #endif /* * This function receives all incoming IP datagrams. */ int ip_rcv(struct sk_buff *skb, struct device *dev, struct packet_type *pt) { struct iphdr *iph = skb->h.iph; struct sock *raw_sk=NULL; unsigned char hash; unsigned char flag = 0; unsigned char opts_p = 0; /* Set iff the packet has options. */ struct inet_protocol *ipprot; static struct options opt; /* since we don't use these yet, and they take up stack space. */ int brd=IS_MYADDR; int is_frag=0; #ifdef CONFIG_IP_FIREWALL int err; #endif ip_statistics.IpInReceives++; /* * Tag the ip header of this packet so we can find it */ skb->ip_hdr = iph; /* * Is the datagram acceptable? * * 1. Length at least the size of an ip header * 2. Version of 4 * 3. Checksums correctly. [Speed optimisation for later, skip loopback checksums] * (4. We ought to check for IP multicast addresses and undefined types.. does this matter ?) */ if (skb->lenihl<5 || iph->version != 4 || ip_fast_csum((unsigned char *)iph, iph->ihl) !=0) { ip_statistics.IpInHdrErrors++; kfree_skb(skb, FREE_WRITE); return(0); } /* * See if the firewall wants to dispose of the packet. */ #ifdef CONFIG_IP_FIREWALL if ((err=ip_fw_chk(iph,dev,ip_fw_blk_chain,ip_fw_blk_policy, 0))!=1) { if(err==-1) icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0, dev); kfree_skb(skb, FREE_WRITE); return 0; } #endif /* * Our transport medium may have padded the buffer out. Now we know it * is IP we can trim to the true length of the frame. */ skb->len=ntohs(iph->tot_len); /* * Next analyse the packet for options. Studies show under one packet in * a thousand have options.... */ if (iph->ihl != 5) { /* Fast path for the typical optionless IP packet. */ memset((char *) &opt, 0, sizeof(opt)); if (do_options(iph, &opt) != 0) return 0; opts_p = 1; } /* * Remember if the frame is fragmented. */ if(iph->frag_off) { if (iph->frag_off & 0x0020) is_frag|=1; /* * Last fragment ? */ if (ntohs(iph->frag_off) & 0x1fff) is_frag|=2; } /* * Do any IP forwarding required. chk_addr() is expensive -- avoid it someday. * * This is inefficient. While finding out if it is for us we could also compute * the routing table entry. This is where the great unified cache theory comes * in as and when someone implements it * * For most hosts over 99% of packets match the first conditional * and don't go via ip_chk_addr. Note: brd is set to IS_MYADDR at * function entry. */ if ( iph->daddr != skb->dev->pa_addr && (brd = ip_chk_addr(iph->daddr)) == 0) { /* * Don't forward multicast or broadcast frames. */ if(skb->pkt_type!=PACKET_HOST || brd==IS_BROADCAST) { kfree_skb(skb,FREE_WRITE); return 0; } /* * The packet is for another target. Forward the frame */ #ifdef CONFIG_IP_FORWARD ip_forward(skb, dev, is_frag); #else /* printk("Machine %lx tried to use us as a forwarder to %lx but we have forwarding disabled!\n", iph->saddr,iph->daddr);*/ ip_statistics.IpInAddrErrors++; #endif /* * The forwarder is inefficient and copies the packet. We * free the original now. */ kfree_skb(skb, FREE_WRITE); return(0); } #ifdef CONFIG_IP_MULTICAST if(brd==IS_MULTICAST && iph->daddr!=IGMP_ALL_HOSTS && !(dev->flags&IFF_LOOPBACK)) { /* * Check it is for one of our groups */ struct ip_mc_list *ip_mc=dev->ip_mc_list; do { if(ip_mc==NULL) { kfree_skb(skb, FREE_WRITE); return 0; } if(ip_mc->multiaddr==iph->daddr) break; ip_mc=ip_mc->next; } while(1); } #endif /* * Account for the packet */ #ifdef CONFIG_IP_ACCT ip_acct_cnt(iph,dev, ip_acct_chain); #endif /* * Reassemble IP fragments. */ if(is_frag) { /* Defragment. Obtain the complete packet if there is one */ skb=ip_defrag(iph,skb,dev); if(skb==NULL) return 0; skb->dev = dev; iph=skb->h.iph; } /* * Point into the IP datagram, just past the header. */ skb->ip_hdr = iph; skb->h.raw += iph->ihl*4; /* * Deliver to raw sockets. This is fun as to avoid copies we want to make no surplus copies. */ hash = iph->protocol & (SOCK_ARRAY_SIZE-1); /* If there maybe a raw socket we must check - if not we don't care less */ if((raw_sk=raw_prot.sock_array[hash])!=NULL) { struct sock *sknext=NULL; struct sk_buff *skb1; raw_sk=get_sock_raw(raw_sk, hash, iph->saddr, iph->daddr); if(raw_sk) /* Any raw sockets */ { do { /* Find the next */ sknext=get_sock_raw(raw_sk->next, hash, iph->saddr, iph->daddr); if(sknext) skb1=skb_clone(skb, GFP_ATOMIC); else break; /* One pending raw socket left */ if(skb1) raw_rcv(raw_sk, skb1, dev, iph->saddr,iph->daddr); raw_sk=sknext; } while(raw_sk!=NULL); /* Here either raw_sk is the last raw socket, or NULL if none */ /* We deliver to the last raw socket AFTER the protocol checks as it avoids a surplus copy */ } } /* * skb->h.raw now points at the protocol beyond the IP header. */ hash = iph->protocol & (MAX_INET_PROTOS -1); for (ipprot = (struct inet_protocol *)inet_protos[hash];ipprot != NULL;ipprot=(struct inet_protocol *)ipprot->next) { struct sk_buff *skb2; if (ipprot->protocol != iph->protocol) continue; /* * See if we need to make a copy of it. This will * only be set if more than one protocol wants it. * and then not for the last one. If there is a pending * raw delivery wait for that */ if (ipprot->copy || raw_sk) { skb2 = skb_clone(skb, GFP_ATOMIC); if(skb2==NULL) continue; } else { skb2 = skb; } flag = 1; /* * Pass on the datagram to each protocol that wants it, * based on the datagram protocol. We should really * check the protocol handler's return values here... */ ipprot->handler(skb2, dev, opts_p ? &opt : 0, iph->daddr, (ntohs(iph->tot_len) - (iph->ihl * 4)), iph->saddr, 0, ipprot); } /* * All protocols checked. * If this packet was a broadcast, we may *not* reply to it, since that * causes (proven, grin) ARP storms and a leakage of memory (i.e. all * ICMP reply messages get queued up for transmission...) */ if(raw_sk!=NULL) /* Shift to last raw user */ raw_rcv(raw_sk, skb, dev, iph->saddr, iph->daddr); else if (!flag) /* Free and report errors */ { if (brd != IS_BROADCAST && brd!=IS_MULTICAST) icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PROT_UNREACH, 0, dev); kfree_skb(skb, FREE_WRITE); } return(0); } /* * Loop a packet back to the sender. */ static void ip_loopback(struct device *old_dev, struct sk_buff *skb) { extern struct device loopback_dev; struct device *dev=&loopback_dev; int len=skb->len-old_dev->hard_header_len; struct sk_buff *newskb=alloc_skb(len+dev->hard_header_len, GFP_ATOMIC); if(newskb==NULL) return; newskb->link3=NULL; newskb->sk=NULL; newskb->dev=dev; newskb->saddr=skb->saddr; newskb->daddr=skb->daddr; newskb->raddr=skb->raddr; newskb->free=1; newskb->lock=0; newskb->users=0; newskb->pkt_type=skb->pkt_type; newskb->len=len+dev->hard_header_len; newskb->ip_hdr=(struct iphdr *)(newskb->data+ip_send(newskb, skb->ip_hdr->daddr, len, dev, skb->ip_hdr->saddr)); memcpy(newskb->ip_hdr,skb->ip_hdr,len); /* Recurse. The device check against IFF_LOOPBACK will stop infinite recursion */ /*printk("Loopback output queued [%lX to %lX].\n", newskb->ip_hdr->saddr,newskb->ip_hdr->daddr);*/ ip_queue_xmit(NULL, dev, newskb, 1); } /* * Queues a packet to be sent, and starts the transmitter * if necessary. if free = 1 then we free the block after * transmit, otherwise we don't. If free==2 we not only * free the block but also don't assign a new ip seq number. * This routine also needs to put in the total length, * and compute the checksum */ void ip_queue_xmit(struct sock *sk, struct device *dev, struct sk_buff *skb, int free) { struct iphdr *iph; unsigned char *ptr; /* Sanity check */ if (dev == NULL) { printk("IP: ip_queue_xmit dev = NULL\n"); return; } IS_SKB(skb); /* * Do some book-keeping in the packet for later */ skb->dev = dev; skb->when = jiffies; /* * Find the IP header and set the length. This is bad * but once we get the skb data handling code in the * hardware will push its header sensibly and we will * set skb->ip_hdr to avoid this mess and the fixed * header length problem */ ptr = skb->data; ptr += dev->hard_header_len; iph = (struct iphdr *)ptr; skb->ip_hdr = iph; iph->tot_len = ntohs(skb->len-dev->hard_header_len); #ifdef CONFIG_IP_FIREWALL if(ip_fw_chk(iph, dev, ip_fw_blk_chain, ip_fw_blk_policy, 0) != 1) /* just don't send this packet */ return; #endif /* * No reassigning numbers to fragments... */ if(free!=2) iph->id = htons(ip_id_count++); else free=1; /* All buffers without an owner socket get freed */ if (sk == NULL) free = 1; skb->free = free; /* * Do we need to fragment. Again this is inefficient. * We need to somehow lock the original buffer and use * bits of it. */ if(skb->len > dev->mtu + dev->hard_header_len) { ip_fragment(sk,skb,dev,0); IS_SKB(skb); kfree_skb(skb,FREE_WRITE); return; } /* * Add an IP checksum */ ip_send_check(iph); /* * Print the frame when debugging */ /* * More debugging. You cannot queue a packet already on a list * Spot this and moan loudly. */ if (skb->next != NULL) { printk("ip_queue_xmit: next != NULL\n"); skb_unlink(skb); } /* * If a sender wishes the packet to remain unfreed * we add it to his send queue. This arguably belongs * in the TCP level since nobody else uses it. BUT * remember IPng might change all the rules. */ if (!free) { unsigned long flags; /* The socket now has more outstanding blocks */ sk->packets_out++; /* Protect the list for a moment */ save_flags(flags); cli(); if (skb->link3 != NULL) { printk("ip.c: link3 != NULL\n"); skb->link3 = NULL; } if (sk->send_head == NULL) { sk->send_tail = skb; sk->send_head = skb; } else { sk->send_tail->link3 = skb; sk->send_tail = skb; } /* skb->link3 is NULL */ /* Interrupt restore */ restore_flags(flags); } else /* Remember who owns the buffer */ skb->sk = sk; /* * If the indicated interface is up and running, send the packet. */ ip_statistics.IpOutRequests++; #ifdef CONFIG_IP_ACCT ip_acct_cnt(iph,dev, ip_acct_chain); #endif #ifdef CONFIG_IP_MULTICAST /* * Multicasts are looped back for other local users */ if (MULTICAST(iph->daddr) && !(dev->flags&IFF_LOOPBACK)) { if(sk==NULL || sk->ip_mc_loop) { if(iph->daddr==IGMP_ALL_HOSTS) ip_loopback(dev,skb); else { struct ip_mc_list *imc=dev->ip_mc_list; while(imc!=NULL) { if(imc->multiaddr==iph->daddr) { ip_loopback(dev,skb); break; } imc=imc->next; } } } /* Multicasts with ttl 0 must not go beyond the host */ if(skb->ip_hdr->ttl==0) { kfree_skb(skb, FREE_READ); return; } } #endif if((dev->flags&IFF_BROADCAST) && iph->daddr==dev->pa_brdaddr && !(dev->flags&IFF_LOOPBACK)) ip_loopback(dev,skb); if (dev->flags & IFF_UP) { /* * If we have an owner use its priority setting, * otherwise use NORMAL */ if (sk != NULL) { dev_queue_xmit(skb, dev, sk->priority); } else { dev_queue_xmit(skb, dev, SOPRI_NORMAL); } } else { ip_statistics.IpOutDiscards++; if (free) kfree_skb(skb, FREE_WRITE); } } #ifdef CONFIG_IP_MULTICAST /* * Write an multicast group list table for the IGMP daemon to * read. */ int ip_mc_procinfo(char *buffer, char **start, off_t offset, int length) { off_t pos=0, begin=0; struct ip_mc_list *im; unsigned long flags; int len=0; struct device *dev; len=sprintf(buffer,"Device : Count\tGroup Users Timer\n"); save_flags(flags); cli(); for(dev = dev_base; dev; dev = dev->next) { if((dev->flags&IFF_UP)&&(dev->flags&IFF_MULTICAST)) { len+=sprintf(buffer+len,"%-10s: %5d\n", dev->name, dev->mc_count); for(im = dev->ip_mc_list; im; im = im->next) { len+=sprintf(buffer+len, "\t\t\t%08lX %5d %d:%08lX\n", im->multiaddr, im->users, im->tm_running, im->timer.expires); pos=begin+len; if(posoffset+length) break; } } } restore_flags(flags); *start=buffer+(offset-begin); len-=(offset-begin); if(len>length) len=length; return len; } #endif /* * Socket option code for IP. This is the end of the line after any TCP,UDP etc options on * an IP socket. * * We implement IP_TOS (type of service), IP_TTL (time to live). * * Next release we will sort out IP_OPTIONS since for some people are kind of important. */ int ip_setsockopt(struct sock *sk, int level, int optname, char *optval, int optlen) { int val,err; #if defined(CONFIG_IP_FIREWALL) || defined(CONFIG_IP_ACCT) struct ip_fw tmp_fw; #endif if (optval == NULL) return(-EINVAL); err=verify_area(VERIFY_READ, optval, sizeof(int)); if(err) return err; val = get_fs_long((unsigned long *)optval); if(level!=SOL_IP) return -EOPNOTSUPP; switch(optname) { case IP_TOS: if(val<0||val>255) return -EINVAL; sk->ip_tos=val; if(val==IPTOS_LOWDELAY) sk->priority=SOPRI_INTERACTIVE; if(val==IPTOS_THROUGHPUT) sk->priority=SOPRI_BACKGROUND; return 0; case IP_TTL: if(val<1||val>255) return -EINVAL; sk->ip_ttl=val; return 0; #ifdef CONFIG_IP_MULTICAST case IP_MULTICAST_TTL: { unsigned char ucval; ucval=get_fs_byte((unsigned char *)optval); if(ucval<1||ucval>255) return -EINVAL; sk->ip_mc_ttl=(int)ucval; return 0; } case IP_MULTICAST_LOOP: { unsigned char ucval; ucval=get_fs_byte((unsigned char *)optval); if(ucval!=0 && ucval!=1) return -EINVAL; sk->ip_mc_loop=(int)ucval; return 0; } case IP_MULTICAST_IF: { /* Not fully tested */ struct in_addr addr; struct device *dev=NULL; /* * Check the arguments are allowable */ err=verify_area(VERIFY_READ, optval, sizeof(addr)); if(err) return err; memcpy_fromfs(&addr,optval,sizeof(addr)); printk("MC bind %s\n", in_ntoa(addr.s_addr)); /* * What address has been requested */ if(addr.s_addr==INADDR_ANY) /* Default */ { sk->ip_mc_name[0]=0; return 0; } /* * Find the device */ for(dev = dev_base; dev; dev = dev->next) { if((dev->flags&IFF_UP)&&(dev->flags&IFF_MULTICAST)&& (dev->pa_addr==addr.s_addr)) break; } /* * Did we find one */ if(dev) { strcpy(sk->ip_mc_name,dev->name); return 0; } return -EADDRNOTAVAIL; } case IP_ADD_MEMBERSHIP: { /* * FIXME: Add/Del membership should have a semaphore protecting them from re-entry */ struct ip_mreq mreq; static struct options optmem; unsigned long route_src; struct rtable *rt; struct device *dev=NULL; /* * Check the arguments. */ err=verify_area(VERIFY_READ, optval, sizeof(mreq)); if(err) return err; memcpy_fromfs(&mreq,optval,sizeof(mreq)); /* * Get device for use later */ if(mreq.imr_interface.s_addr==INADDR_ANY) { /* * Not set so scan. */ if((rt=ip_rt_route(mreq.imr_multiaddr.s_addr,&optmem, &route_src))!=NULL) { dev=rt->rt_dev; rt->rt_use--; } } else { /* * Find a suitable device. */ for(dev = dev_base; dev; dev = dev->next) { if((dev->flags&IFF_UP)&&(dev->flags&IFF_MULTICAST)&& (dev->pa_addr==mreq.imr_interface.s_addr)) break; } } /* * No device, no cookies. */ if(!dev) return -ENODEV; /* * Join group. */ return ip_mc_join_group(sk,dev,mreq.imr_multiaddr.s_addr); } case IP_DROP_MEMBERSHIP: { struct ip_mreq mreq; struct rtable *rt; static struct options optmem; unsigned long route_src; struct device *dev=NULL; /* * Check the arguments */ err=verify_area(VERIFY_READ, optval, sizeof(mreq)); if(err) return err; memcpy_fromfs(&mreq,optval,sizeof(mreq)); /* * Get device for use later */ if(mreq.imr_interface.s_addr==INADDR_ANY) { if((rt=ip_rt_route(mreq.imr_multiaddr.s_addr,&optmem, &route_src))!=NULL) { dev=rt->rt_dev; rt->rt_use--; } } else { for(dev = dev_base; dev; dev = dev->next) { if((dev->flags&IFF_UP)&& (dev->flags&IFF_MULTICAST)&& (dev->pa_addr==mreq.imr_interface.s_addr)) break; } } /* * Did we find a suitable device. */ if(!dev) return -ENODEV; /* * Leave group */ return ip_mc_leave_group(sk,dev,mreq.imr_multiaddr.s_addr); } #endif #ifdef CONFIG_IP_FIREWALL case IP_FW_ADD_BLK: case IP_FW_DEL_BLK: case IP_FW_ADD_FWD: case IP_FW_DEL_FWD: case IP_FW_CHK_BLK: case IP_FW_CHK_FWD: case IP_FW_FLUSH_BLK: case IP_FW_FLUSH_FWD: case IP_FW_ZERO_BLK: case IP_FW_ZERO_FWD: case IP_FW_POLICY_BLK: case IP_FW_POLICY_FWD: if(!suser()) return -EPERM; if(optlen>sizeof(tmp_fw) || optlen<1) return -EINVAL; err=verify_area(VERIFY_READ,optval,optlen); if(err) return err; memcpy_fromfs(&tmp_fw,optval,optlen); err=ip_fw_ctl(optname, &tmp_fw,optlen); return -err; /* -0 is 0 after all */ #endif #ifdef CONFIG_IP_ACCT case IP_ACCT_DEL: case IP_ACCT_ADD: case IP_ACCT_FLUSH: case IP_ACCT_ZERO: if(!suser()) return -EPERM; if(optlen>sizeof(tmp_fw) || optlen<1) return -EINVAL; err=verify_area(VERIFY_READ,optval,optlen); if(err) return err; memcpy_fromfs(&tmp_fw, optval,optlen); err=ip_acct_ctl(optname, &tmp_fw,optlen); return -err; /* -0 is 0 after all */ #endif /* IP_OPTIONS and friends go here eventually */ default: return(-ENOPROTOOPT); } } /* * Get the options. Note for future reference. The GET of IP options gets the * _received_ ones. The set sets the _sent_ ones. */ int ip_getsockopt(struct sock *sk, int level, int optname, char *optval, int *optlen) { int val,err; #ifdef CONFIG_IP_MULTICAST int len; #endif if(level!=SOL_IP) return -EOPNOTSUPP; switch(optname) { case IP_TOS: val=sk->ip_tos; break; case IP_TTL: val=sk->ip_ttl; break; #ifdef CONFIG_IP_MULTICAST case IP_MULTICAST_TTL: val=sk->ip_mc_ttl; break; case IP_MULTICAST_LOOP: val=sk->ip_mc_loop; break; case IP_MULTICAST_IF: err=verify_area(VERIFY_WRITE, optlen, sizeof(int)); if(err) return err; len=strlen(sk->ip_mc_name); err=verify_area(VERIFY_WRITE, optval, len); if(err) return err; put_fs_long(len,(unsigned long *) optlen); memcpy_tofs((void *)optval,sk->ip_mc_name, len); return 0; #endif default: return(-ENOPROTOOPT); } err=verify_area(VERIFY_WRITE, optlen, sizeof(int)); if(err) return err; put_fs_long(sizeof(int),(unsigned long *) optlen); err=verify_area(VERIFY_WRITE, optval, sizeof(int)); if(err) return err; put_fs_long(val,(unsigned long *)optval); return(0); } /* * IP protocol layer initialiser */ static struct packet_type ip_packet_type = { 0, /* MUTTER ntohs(ETH_P_IP),*/ NULL, /* All devices */ ip_rcv, NULL, NULL, }; /* * Device notifier */ static int ip_rt_event(unsigned long event, void *ptr) { if(event==NETDEV_DOWN) ip_rt_flush(ptr); return NOTIFY_DONE; } struct notifier_block ip_rt_notifier={ ip_rt_event, NULL, 0 }; /* * IP registers the packet type and then calls the subprotocol initialisers */ void ip_init(void) { ip_packet_type.type=htons(ETH_P_IP); dev_add_pack(&ip_packet_type); /* So we flush routes when a device is downed */ register_netdevice_notifier(&ip_rt_notifier); /* ip_raw_init(); ip_packet_init(); ip_tcp_init(); ip_udp_init();*/ }