diff options
Diffstat (limited to 'pfinet/linux-inet/ip.c')
| -rw-r--r-- | pfinet/linux-inet/ip.c | 2427 |
1 files changed, 0 insertions, 2427 deletions
diff --git a/pfinet/linux-inet/ip.c b/pfinet/linux-inet/ip.c deleted file mode 100644 index dd188f54..00000000 --- a/pfinet/linux-inet/ip.c +++ /dev/null @@ -1,2427 +0,0 @@ -/* - * 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, <bir7@leland.Stanford.Edu> - * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> - * Donald Becker, <becker@super.org> - * Alan Cox, <gw4pts@gw4pts.ampr.org> - * Richard Underwood - * Stefan Becker, <stefanb@yello.ping.de> - * - * - * 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 <asm/segment.h> -#include <asm/system.h> -#include <linux/types.h> -#include <linux/kernel.h> -#include <linux/sched.h> -#include <linux/mm.h> -#include <linux/string.h> -#include <linux/errno.h> -#include <linux/config.h> - -#include <linux/socket.h> -#include <linux/sockios.h> -#include <linux/in.h> -#include <linux/inet.h> -#include <linux/netdevice.h> -#include <linux/etherdevice.h> - -#include "snmp.h" -#include "ip.h" -#include "protocol.h" -#include "route.h" -#include "tcp.h" -#include "udp.h" -#include <linux/skbuff.h> -#include "sock.h" -#include "arp.h" -#include "icmp.h" -#include "raw.h" -#include <linux/igmp.h> -#include <linux/ip_fw.h> - -#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->len<sizeof(struct iphdr) || iph->ihl<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(pos<offset) - { - len=0; - begin=pos; - } - if(pos>offset+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();*/ -} |