diff options
Diffstat (limited to 'package/siit/src/siit.c')
| -rw-r--r-- | package/siit/src/siit.c | 1478 |
1 files changed, 0 insertions, 1478 deletions
diff --git a/package/siit/src/siit.c b/package/siit/src/siit.c deleted file mode 100644 index 5362c1daa..000000000 --- a/package/siit/src/siit.c +++ /dev/null @@ -1,1478 +0,0 @@ -/* - * siit.c: the Stateless IP/ICMP Translator (SIIT) module for Linux. - * - * - */ - -#include <linux/version.h> -#if (LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,33)) -#include <generated/autoconf.h> -#else -#include <linux/autoconf.h> -#endif -#include <linux/module.h> -#include <linux/sched.h> -#include <linux/kernel.h> /* printk() */ -#include <linux/slab.h> - -#include <linux/errno.h> /* error codes */ -#include <linux/types.h> /* size_t */ -#include <linux/interrupt.h> /* mark_bh */ -#include <linux/random.h> -#include <linux/in.h> -#include <linux/netdevice.h> /* struct device, and other headers */ -#include <linux/etherdevice.h> /* eth_type_trans */ -#include <net/ip.h> /* struct iphdr */ -#include <net/icmp.h> /* struct icmphdr */ -#include <net/ipv6.h> -#include <net/udp.h> -#include <linux/skbuff.h> -#include <linux/in6.h> -#include <linux/init.h> -#include <asm/uaccess.h> -#include <asm/checksum.h> -#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,0) -#include <net/ip6_checksum.h> -#endif -#include <linux/in6.h> -#include "siit.h" - -MODULE_AUTHOR("Dmitriy Moscalev, Grigory Klyuchnikov, Felix Fietkau"); - -/* - * If tos_ignore_flag != 0, we don't copy TOS and Traffic Class - * from origin paket and set it to 0 - */ -int tos_ignore_flag = 0; - -#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0) -static inline void -skb_reset_mac_header(struct sk_buff *skb) -{ - skb->mac.raw=skb->data; -} - -static struct net_device_stats * -siit_get_stats(struct net_device *dev) -{ - return netdev_priv(dev); -} - -static inline void random_ether_addr(u8 *addr) -{ - get_random_bytes (addr, ETH_ALEN); - addr [0] &= 0xfe; /* clear multicast bit */ - addr [0] |= 0x02; /* set local assignment bit (IEEE802) */ -} - - -#define siit_stats(_dev) ((struct net_device_stats *)netdev_priv(_dev)) -#else -#define siit_stats(_dev) (&(_dev)->stats) -#endif - -/* - * The Utility stuff - */ - -#ifdef SIIT_DEBUG -/* print dump bytes (data point data area sizeof len and message - * before dump. - */ -static int siit_print_dump(char *data, int len, char *message) -{ - int i; - int j = 0, k = 1; - - len = len > BUFF_SIZE ? BUFF_SIZE : len; - printk("%s:\n", message); - for (i=0; i < len; i++, k++) { - if( i == len-1 || k == 16) { - printk("%02x\n", (~(~0 << 8) & *(data+i))); - j = 0; - k = 0; - } - else if (j) { - printk("%02x ", (~(~0 << 8) & *(data+i))); - j--; - } - else { - printk("%02x", (~(~0 << 8) & *(data+i))); - j++; - } - } - return 0; -} -#endif - -/* - * Open and close - */ -static int siit_open(struct net_device *dev) -{ - netif_start_queue(dev); - return 0; -} - - -static int siit_release(struct net_device *dev) -{ - netif_stop_queue(dev); /* can't transmit any more */ - return 0; -} - -/* - * Translation IPv4 to IPv6 stuff - * - * ip4_ip6 (src, len, dst, include_flag) - * - * where - * src - buffer with original IPv4 packet, - * len - size of original packet, - * dst - new buffer for IPv6 packet, - * include_flag - if = 1, dst point to IPv4 packet that is ICMP error - * included IP packet, else = 0 - */ - -static int ip4_ip6(char *src, int len, char *dst, int include_flag) -{ - struct iphdr *ih4 = (struct iphdr *) src; /* point to current IPv4 header struct */ - struct icmphdr *icmp_hdr; /* point to current ICMPv4 header struct */ - struct udphdr *udp_hdr; /* point to current IPv4 UDP header struct */ - - struct ipv6hdr *ih6 = (struct ipv6hdr *) dst; /* point to current IPv6 header struct */ - struct frag_hdr *ih6_frag = (struct frag_hdr *)(dst+sizeof(struct ipv6hdr)); - /* point to current IPv6 fragment header struct */ - struct icmp6hdr *icmp6_hdr; /* point to current ICMPv6 header */ - - int hdr_len = (int)(ih4->ihl * 4); /* IPv4 header length */ - int icmp_len; /* ICMPv4 packet length */ - int plen; /* payload length */ - - unsigned int csum; /* need to calculate ICMPv6 and UDP checksum */ - int fl_csum = 0; /* flag to calculate UDP checksum */ - int icmperr = 1; /* flag to indicate ICMP error message and to need - translate ICMP included IP packet */ - int fr_flag = 0; /* fragment flag, if = 0 - don't add - fragment header */ - __u16 new_tot_len; /* need to calculate IPv6 total length */ - __u8 new_nexthdr; /* next header code */ - __u16 icmp_ptr = 0; /* Pointer field in ICMP_PARAMETERPROB */ - -#ifdef SIIT_DEBUG /* print IPv4 header dump */ - siit_print_dump(src, hdr_len, "siit: ip4_ip6() (in) ip4 header dump"); -#endif - - /* If DF == 1 && MF == 0 && Fragment Offset == 0 - * or this packet is ICMP included IP packet - * we don't need fragment header */ - if (ntohs(ih4->frag_off) == IP_DF || include_flag ) { - /* not fragment and we need not to add Fragment - * Header to IPv6 packet. */ - /* total length = total length from IPv4 packet */ - new_tot_len = ntohs(ih4->tot_len); - - if (ih4->protocol == IPPROTO_ICMP) - new_nexthdr = NEXTHDR_ICMP; - else - new_nexthdr = ih4->protocol; - } - else { - /* need to add Fragment Header */ - fr_flag = 1; - /* total length = total length from IPv4 packet + - length of Fragment Header */ - new_tot_len = ntohs(ih4->tot_len) + sizeof(struct frag_hdr); - /* IPv6 Header NextHeader = NEXTHDR_FRAGMENT */ - new_nexthdr = NEXTHDR_FRAGMENT; - /* Fragment Header NextHeader copy from IPv4 packet */ - if (ih4->protocol == IPPROTO_ICMP) - ih6_frag->nexthdr = NEXTHDR_ICMP; - else - ih6_frag->nexthdr = ih4->protocol; - - /* copy frag offset from IPv4 packet */ - ih6_frag->frag_off = htons((ntohs(ih4->frag_off) & IP_OFFSET) << 3); - /* copy MF flag from IPv4 packet */ - ih6_frag->frag_off = htons((ntohs(ih6_frag->frag_off) | - ((ntohs(ih4->frag_off) & IP_MF) >> 13))); - /* copy Identification field from IPv4 packet */ - ih6_frag->identification = htonl(ntohs(ih4->id)); - /* reserved field initialized to zero */ - ih6_frag->reserved = 0; - } - - /* Form rest IPv6 fields */ - - /* - * At this point we need to add checking of unxpired source - * route optin and if it is, send ICMPv4 "destination - * unreacheble/source route failes" Type 3/Code 5 and - * drop packet. (NOT RELEASED YET) - */ - - /* IP version = 6 */ - ih6->version = 6; - - if (tos_ignore_flag) { - ih6->priority = 0; - ih6->flow_lbl[0] = 0; - } else { - ih6->priority = (ih4->tos & 0xf0) >> 4; - ih6->flow_lbl[0] = (ih4->tos & 0x0f) << 4; - } - ih6->flow_lbl[1] = 0; - ih6->flow_lbl[2] = 0; - - /* Hop Limit = IPv4 TTL */ - ih6->hop_limit = ih4->ttl; - - /* Translate source destination addresses, - for IPv6 host it's IPv4-translated IPv6 address, - for IPv4 host it's IPv4-mapped IPv6 address - - !!WARNING!! Instead IPv4-mapped IPv6 addresses we use addreesses - with unused prefix ::ffff:ffff:0:0/96, because KAME implementation - doesn't support IPv4-mapped addresses in IPv6 packets and discard them. - - */ - - if (include_flag) { - /* - It's ICMP included IP packet and there is a diffirence - in src/dst addresses then src/dst in normal direction - */ - - /* - Source address - is IPv4-translated IPv6 address because packet traveled - from IPv6 to IPv4 area - */ - ih6->saddr.in6_u.u6_addr32[0] = 0; - ih6->saddr.in6_u.u6_addr32[1] = 0; - ih6->saddr.in6_u.u6_addr32[2] = htonl(TRANSLATED_PREFIX); /* to network order bytes */ - ih6->saddr.in6_u.u6_addr32[3] = ih4->saddr; - - /* - Destination address - is IPv4-mapped address (but it's not IPv4- mapped, we use - prefix ::ffff:ffff:0:0/96 - */ - ih6->daddr.in6_u.u6_addr32[0] = 0; - ih6->daddr.in6_u.u6_addr32[1] = 0; - ih6->daddr.in6_u.u6_addr32[2] = htonl(MAPPED_PREFIX); /* to network order bytes */ - ih6->daddr.in6_u.u6_addr32[3] = ih4->daddr; - } - else { - - /* - This is normal case (packet isn't included IP packet) - - Source address - is IPv4-mapped address (but it's not IPv4- mapped, we use - prefix ::ffff:ffff:0:0/96) - */ - ih6->saddr.in6_u.u6_addr32[0] = 0; - ih6->saddr.in6_u.u6_addr32[1] = 0; - ih6->saddr.in6_u.u6_addr32[2] = htonl(MAPPED_PREFIX); /* to network order bytes */ - ih6->saddr.in6_u.u6_addr32[3] = ih4->saddr; - - /* Destination address - is is IPv4-translated IPv6 address - */ - ih6->daddr.in6_u.u6_addr32[0] = 0; - ih6->daddr.in6_u.u6_addr32[1] = 0; - ih6->daddr.in6_u.u6_addr32[2] = htonl(TRANSLATED_PREFIX); /* to network order bytes */ - ih6->daddr.in6_u.u6_addr32[3] = ih4->daddr; - } - - /* Payload Length */ - plen = new_tot_len - hdr_len; /* Payload length = IPv4 total len - IPv4 header len */ - ih6->payload_len = htons(plen); - - /* Next Header */ - ih6->nexthdr = new_nexthdr; /* Next Header */ - - /* Process ICMP protocols data */ - - switch (ih4->protocol) { - case IPPROTO_ICMP: - if ( (ntohs(ih4->frag_off) & IP_OFFSET) != 0 || (ntohs(ih4->frag_off) & IP_MF) != 0 ) { - PDEBUG("ip4_ip6(): don't translate ICMPv4 fragments - packet dropped.\n"); - return -1; - } - - icmp_hdr = (struct icmphdr *) (src+hdr_len); /* point to ICMPv4 header */ - csum = 0; - icmp_len = ntohs(ih4->tot_len) - hdr_len; /* ICMPv4 packet length */ - icmp6_hdr = (struct icmp6hdr *)(dst+sizeof(struct ipv6hdr) - +fr_flag*sizeof(struct frag_hdr)); /* point to ICMPv6 header */ - - if (include_flag) { - /* ICMPv4 packet cannot be included in ICMPv4 Error message */ - /* !!! May be it's WRONG !!! ICMPv4 QUERY packet can be included - in ICMPv4 Error message */ - PDEBUG("ip4_ip6(): It's included ICMPv4 in ICMPv4 Error message - packet dropped.\n"); - return -1; - } - - /* Check ICMPv4 Type field */ - switch (icmp_hdr->type) { - /* ICMP Error messages */ - /* Destination Unreachable (Type 3) */ - case ICMP_DEST_UNREACH: - icmp6_hdr->icmp6_type = ICMPV6_DEST_UNREACH; /* to Type 1 */ - icmp6_hdr->icmp6_unused = 0; - switch (icmp_hdr->code) - { - case ICMP_NET_UNREACH: /* Code 0 */ - case ICMP_HOST_UNREACH: /* Code 1 */ - case ICMP_SR_FAILED: /* Code 5 */ - case ICMP_NET_UNKNOWN: /* Code 6 */ - case ICMP_HOST_UNKNOWN: /* Code 7 */ - case ICMP_HOST_ISOLATED: /* Code 8 */ - case ICMP_NET_UNR_TOS: /* Code 11 */ - case ICMP_HOST_UNR_TOS: /* Code 12 */ - icmp6_hdr->icmp6_code = ICMPV6_NOROUTE; /* to Code 0 */ - break; - case ICMP_PROT_UNREACH: /* Code 2 */ - icmp6_hdr->icmp6_type = ICMPV6_PARAMPROB; /* to Type 4 */ - icmp6_hdr->icmp6_code = ICMPV6_UNK_NEXTHDR; /* to Code 1 */ - /* Set pointer filed to 6, it's octet offset IPv6 Next Header field */ - icmp6_hdr->icmp6_pointer = htonl(6); - break; - case ICMP_PORT_UNREACH: /* Code 3 */ - icmp6_hdr->icmp6_code = ICMPV6_PORT_UNREACH; /* to Code 4 */ - break; - case ICMP_FRAG_NEEDED: /* Code 4 */ - icmp6_hdr->icmp6_type = ICMPV6_PKT_TOOBIG; /* to Type 2 */ - icmp6_hdr->icmp6_code = 0; - /* Correct MTU */ - if (icmp_hdr->un.frag.mtu == 0) - /* we use minimum MTU for IPv4 PMTUv4 RFC1191, section 5; - IPv6 implementation wouldn't accept Path MTU < 1280, - but it records info correctly to always include - a fragment header */ - icmp6_hdr->icmp6_mtu = htonl(576); - else - /* needs to adjusted for difference between IPv4/IPv6 headers - * SIIT RFC2765, section 3.3, - * we assume that difference is 20 bytes */ - icmp6_hdr->icmp6_mtu = htonl(ntohs(icmp_hdr->un.frag.mtu)+IP4_IP6_HDR_DIFF); - - break; - case ICMP_NET_ANO: /* Code 9 */ - case ICMP_HOST_ANO: /* Code 10 */ - icmp6_hdr->icmp6_code = ICMPV6_ADM_PROHIBITED; /* to Code 1 */ - break; - default: /* discard any other Code */ - PDEBUG("ip4_ip6(): Unknown ICMPv4 Type %d Code %d - packet dropped.\n", - ICMP_DEST_UNREACH, icmp_hdr->code); - return -1; - } - break; - /* Time Exceeded (Type 11) */ - case ICMP_TIME_EXCEEDED: - icmp6_hdr->icmp6_type = ICMPV6_TIME_EXCEED; - icmp6_hdr->icmp6_code = icmp_hdr->code; - break; - /* Parameter Problem (Type 12) */ - case ICMP_PARAMETERPROB: - icmp6_hdr->icmp6_type = ICMPV6_PARAMPROB; - icmp6_hdr->icmp6_code = icmp_hdr->code; - - icmp_ptr = ntohs(icmp_hdr->un.echo.id) >> 8; - switch (icmp_ptr) { - case 0: - icmp6_hdr->icmp6_pointer = 0; /* IPv4 Version -> IPv6 Version */ - break; - case 2: - icmp6_hdr->icmp6_pointer = __constant_htonl(4); /* IPv4 length -> IPv6 Payload Length */ - break; - case 8: - icmp6_hdr->icmp6_pointer = __constant_htonl(7); /* IPv4 TTL -> IPv6 Hop Limit */ - break; - case 9: - icmp6_hdr->icmp6_pointer = __constant_htonl(6); /* IPv4 Protocol -> IPv6 Next Header */ - break; - case 12: - icmp6_hdr->icmp6_pointer = __constant_htonl(8); /* IPv4 Src Addr -> IPv6 Src Addr */ - break; - case 16: - icmp6_hdr->icmp6_pointer = __constant_htonl(24); /* IPv4 Dst Addr -> IPv6 Dst Addr */ - break; - default: - icmp6_hdr->icmp6_pointer = 0xffffffff; /* set to all ones in any other cases */ - break; - } - break; - case ICMP_ECHO: - icmperr = 0; - icmp6_hdr->icmp6_type = ICMPV6_ECHO_REQUEST; - icmp6_hdr->icmp6_code = 0; - /* Copy rest ICMP data to new IPv6 packet without changing */ - memcpy(((char *)icmp6_hdr)+4, ((char *)icmp_hdr)+4, len - hdr_len - 4); - break; - - case ICMP_ECHOREPLY: - icmperr = 0; - icmp6_hdr->icmp6_type = ICMPV6_ECHO_REPLY; - icmp6_hdr->icmp6_code = 0; - /* Copy rest ICMP data to new IPv6 packet without changing */ - memcpy(((char *)icmp6_hdr)+4, ((char *)icmp_hdr)+4, len - hdr_len - 4); - break; - - /* Discard any other ICMP messages */ - default: - PDEBUG("ip4_ip6(): Unknown ICMPv4 packet Type %x - packet dropped.\n", icmp_hdr->type); - return -1; - } - - /* Now if it's ICMPv4 Error message we must translate included IP packet */ - - if (icmperr) { - /* Call our ip4_ip6() to translate included IP packet */ - if (ip4_ip6(src+hdr_len+sizeof(struct icmphdr), len - hdr_len - sizeof(struct icmphdr), - dst+sizeof(struct ipv6hdr)+fr_flag*sizeof(struct frag_hdr) - +sizeof(struct icmp6hdr), 1) == -1) { - PDEBUG("ip4_ip6(): Uncorrect translation of ICMPv4 Error message - packet dropped.\n"); - return -1; - } - /* correct ICMPv6 packet length for diffirence between IPv4 and IPv6 headers - in included IP packet - */ - icmp_len += 20; - /* and correct Payload length for diffirence between IPv4 and IPv6 headers */ - plen += 20; - ih6->payload_len = htons(plen); - } - - /* Calculate ICMPv6 checksum */ - - icmp6_hdr->icmp6_cksum = 0; - csum = 0; - - csum = csum_partial((u_char *)icmp6_hdr, icmp_len, csum); - icmp6_hdr->icmp6_cksum = csum_ipv6_magic(&ih6->saddr, &ih6->daddr, icmp_len, - IPPROTO_ICMPV6, csum); - break; - - /* Process TCP protocols data */ - case IPPROTO_TCP: - /* Copy TCP data to new IPv6 packet without changing */ - memcpy(dst+sizeof(struct ipv6hdr)+fr_flag*sizeof(struct frag_hdr), - src+hdr_len, len - hdr_len); - break; - - /* Process UDP protocols data */ - case IPPROTO_UDP: - udp_hdr = (struct udphdr *)(src+hdr_len); - if ((ntohs(ih4->frag_off) & IP_OFFSET) == 0) { - if ((ntohs(ih4->frag_off) & IP_MF) != 0) { - /* It's a first fragment */ - if (udp_hdr->check == 0) { - /* System management event */ - printk("siit: First fragment of UDP with zero checksum - packet droped\n"); - printk("siit: addr: %x src port: %d dst port: %d\n", - htonl(ih4->saddr), htons(udp_hdr->source), htons(udp_hdr->dest)); - return -1; - } - } - else if (udp_hdr->check == 0) - fl_csum = 1; - } - - /* Copy UDP data to new IPv6 packet */ - udp_hdr = (struct udphdr *)(dst+sizeof(struct ipv6hdr) - + fr_flag*sizeof(struct frag_hdr)); - memcpy((char *)udp_hdr, src+hdr_len, len - hdr_len); - - /* Calculate UDP checksum if UDP checksum in IPv4 packet was ZERO - and if it isn't included IP packet - */ - if (fl_csum && (!include_flag)) { - udp_hdr->check = 0; - csum = 0; - csum = csum_partial((unsigned char *)udp_hdr, plen - fr_flag*sizeof(struct frag_hdr), csum); - udp_hdr->check = csum_ipv6_magic(&ih6->saddr, &ih6->daddr, plen - - fr_flag*sizeof(struct frag_hdr), IPPROTO_UDP, csum); - } - break; - - /* Discard packets with any other protocol */ - default: - PDEBUG("ip4_ip6(): Unknown upper protocol - packet dropped.\n"); - return -1; - } - -#ifdef SIIT_DEBUG - siit_print_dump(dst, sizeof(struct ipv6hdr), "siit: ip4_ip6(): (out) ipv6 header dump"); -#endif - - return 0; -} - -/* - * Translation IPv6 to IPv4 stuff - * - * ip6_ip4(src, len, dst, include_flag) - * - * where - * src - buffer with original IPv6 packet, - * len - size of original packet, - * dst - new buffer for IPv4 packet, - * include_flag - if = 1, dst point to IPv6 packet that is ICMP error - * included IP packet, else = 0 - * - */ - -static int ip6_ip4(char *src, int len, char *dst, int include_flag) -{ - struct ipv6hdr *ip6_hdr; /* point to current IPv6 header struct */ - struct iphdr *ip_hdr; /* point to current IPv4 header struct */ - int opts_len = 0; /* to sum Option Headers length */ - int icmperr = 1; /* if = 1, indicate that packet is ICMP Error message, else = 0 */ - int ntot_len = 0; /* to calculate IPv6 Total Length field */ - int real_len; - int len_delta; - int ip6_payload_len; - int inc_opts_len = 0; /* to sum Option Headers length in ICMP included IP packet */ - __u8 next_hdr; /* Next Header */ - -#ifdef SIIT_DEBUG - siit_print_dump(src, sizeof(struct ipv6hdr), "siit: ip6_ip4(): (in) ipv6 header dump"); -#endif - - if ( (len_delta = len - sizeof(struct ipv6hdr)) >= 0) - { - ip6_hdr = (struct ipv6hdr *)src; - ip_hdr = (struct iphdr *)dst; - - real_len = sizeof(struct iphdr); - - /* Check validation of Saddr & Daddr? is a packet to fall under our translation? */ - if (include_flag) { /* It's ICMP included IP packet, - about process include_flag see comment in ip4_ip6() */ - if (ip6_hdr->saddr.s6_addr32[2] != htonl(MAPPED_PREFIX)) { - PDEBUG("ip6_ip4(): Included IP packet Src addr isn't mapped addr: %x%x%x%x, packet dropped.\n", - ip6_hdr->saddr.s6_addr32[0], ip6_hdr->saddr.s6_addr32[1], - ip6_hdr->saddr.s6_addr32[2], ip6_hdr->saddr.s6_addr32[3]); - return -1; - } - if ( ip6_hdr->daddr.s6_addr32[2] != htonl(TRANSLATED_PREFIX)) { - PDEBUG("ip6_ip4(): Included IP packet Dst addr isn't translated addr: %x%x%x%x, packet dropped.\n", - ip6_hdr->daddr.s6_addr32[0], ip6_hdr->daddr.s6_addr32[1], - ip6_hdr->daddr.s6_addr32[2], ip6_hdr->daddr.s6_addr32[3]); - return -1; - } - } - else { /* It's normal IP packet (not included in ICMP) */ - if (ip6_hdr->saddr.s6_addr32[2] != htonl(TRANSLATED_PREFIX)) { - PDEBUG("ip6_ip4(): Src addr isn't translated addr: %x%x%x%x, packet dropped.\n", - ip6_hdr->saddr.s6_addr32[0], ip6_hdr->saddr.s6_addr32[1], - ip6_hdr->saddr.s6_addr32[2], ip6_hdr->saddr.s6_addr32[3]); - return -1; - } - if ( ip6_hdr->daddr.s6_addr32[2] != htonl(MAPPED_PREFIX)) { - PDEBUG("ip6_ip4(): Dst addr isn't mapped addr: %x%x%x%x, packet dropped.\n", - ip6_hdr->daddr.s6_addr32[0], ip6_hdr->daddr.s6_addr32[1], - ip6_hdr->daddr.s6_addr32[2], ip6_hdr->daddr.s6_addr32[3]); - return -1; - } - } - - /* Set IPv4 Fragment Offset and ID to 0 - before process any Option Headers */ - ip_hdr->frag_off = 0; - ip_hdr->id = 0; - - /* - * We process only Fragment Header. Any other options headers - * are ignored, i.e. there is no attempt to translate them. - * However, the Total Length field and the Protocol field would - * have to be adjusted to "skip" these extension headers. - */ - - next_hdr = ip6_hdr->nexthdr; - - /* Hop_by_Hop options header (ip6_hdr->nexthdr = 0). It must - * appear only in IPv6 header's Next Header field. - */ - if (next_hdr == NEXTHDR_HOP) { - if ( (len_delta - sizeof(struct ipv6_opt_hdr)) >= 0) - { - struct ipv6_opt_hdr *ip6h = - (struct ipv6_opt_hdr *)(src+sizeof(struct ipv6hdr) + opts_len); - if ( (len_delta -= ip6h->hdrlen*8 + 8) >= 0) - { - opts_len += ip6h->hdrlen*8 + 8; /* See RFC 2460 page 11: - Hdr Ext Len 8-bit unsigned integer. Length of the Hop-by- - Hop Options header in 8-octet units, not - including the first 8 octets. - */ - next_hdr = ip6h->nexthdr; - } - else - { - PDEBUG("ip6_ip4(): hop_by_hop header error, packet droped"); - /* Generate ICMP Parameter Problem */ - return -1; - } - } - } - - if (len_delta > 0) - { - while(next_hdr != NEXTHDR_ICMP && next_hdr != NEXTHDR_TCP - && next_hdr != NEXTHDR_UDP) - { - /* Destination options header */ - if (next_hdr == NEXTHDR_DEST) - { - if ( (len_delta - sizeof(struct ipv6_opt_hdr)) >= 0) - { - struct ipv6_opt_hdr *ip6d = - (struct ipv6_opt_hdr *)(src + sizeof(struct ipv6hdr) + opts_len); - if ( (len_delta -= ip6d->hdrlen*8 + 8) >= 0) - { - opts_len += ip6d->hdrlen*8 + 8; - next_hdr = ip6d->nexthdr; - } - } - else - { - PDEBUG("ip6_ip4(): destination header error, packet droped"); - /* Generate ICMP Parameter Problem */ - return -1; - } - } - /* Routing options header */ - else if (next_hdr == NEXTHDR_ROUTING) - { - if ( (len_delta - sizeof(struct ipv6_rt_hdr)) >= 0) - { - struct ipv6_rt_hdr *ip6rt = - (struct ipv6_rt_hdr *)(src+sizeof(struct ipv6hdr) + opts_len); - /* RFC 2765 SIIT, 4.1: - If a routing header with a non-zero Segments Left field is present - then the packet MUST NOT be translated, and an ICMPv6 "parameter - problem/ erroneous header field encountered" (Type 4/Code 0) error - message, with the Pointer field indicating the first byte of the - Segments Left field, SHOULD be returned to the sender. - */ - if (ip6rt->segments_left != 0) { - /* Build ICMPv6 "Parameter Problem/Erroneous Header - Field Encountered" & drop the packet */ - /* !!! We don't send ICMPv6 "Parameter Problem" !!! */ - PDEBUG("ip6_ip4(): routing header type != 0\n"); - return -1; - } - if ( (len_delta -= ip6rt->hdrlen*8 + 8) >= 0) - { - opts_len += ip6rt->hdrlen*8 + 8; - next_hdr = ip6rt->nexthdr; - } - else - { - PDEBUG("ip6_ip4(): routing header error, packet droped"); - /* Generate ICMP Parameter Problem */ - return -1; - } - } - } - /* Fragment options header */ - else if (next_hdr == NEXTHDR_FRAGMENT) - { - if ( (len_delta -= sizeof(struct frag_hdr)) >= 0) - { - struct frag_hdr *ip6f = - (struct frag_hdr *)(src+sizeof(struct ipv6hdr)+opts_len); - - opts_len += sizeof(struct frag_hdr); /* Frag Header Length = 8 */ - ip_hdr->id = htons(ntohl(ip6f->identification)); /* ID field */ - ip_hdr->frag_off = htons((ntohs(ip6f->frag_off) & IP6F_OFF_MASK) >> 3); - /* fragment offset */ - ip_hdr->frag_off = htons(ntohs(ip_hdr->frag_off) | - ((ntohs(ip6f->frag_off) & IP6F_MORE_FRAG) << 13)); - /* more fragments flag */ - next_hdr = ip6f->nexthdr; - } - else - { - PDEBUG("ip6_ip4(): fragment header error, packet droped"); - /* Generate ICMP Parameter Problem */ - return -1; - } - } - /* No Next Header */ - else if (next_hdr == NEXTHDR_NONE) - { - /* RFC 2460 IPv6 Specification, 4.7 - 4.7 No Next Header - - The value 59 in the Next Header field of an IPv6 header or any - extension header indicates that there is nothing following that - header. If the Payload Length field of the IPv6 header indicates the - presence of octets past the end of a header whose Next Header field - contains 59, those octets must be ignored, and passed on unchanged if - the packet is forwarded. - */ - break; - } - else if (next_hdr == NEXTHDR_ESP || next_hdr == NEXTHDR_AUTH) - { - PDEBUG("ip6_ip4(): cannot translate AUTH or ESP extention header, packet dropped\n"); - return -1; - } - else if (next_hdr == NEXTHDR_IPV6) - { - PDEBUG("ip6_ip4(): cannot translate IPv6-IPv6 packet, packet dropped\n"); - return -1; - } - else if (next_hdr == 0) - { - /* As say RFC 2460 (IPv6 Spec) we should discard the packet and send an - ICMP Parameter Problem message to the source of the packet, with an - ICMP Code value of 1 ("unrecognized Next Header type encountered") - and the ICMP Pointer field containing the offset of the unrecognized - value within the original packet - */ - /* NOT IMPLEMENTED */ - PDEBUG("ip6_ip4(): NEXTHDR in extention header = 0, packet dropped\n"); - return -1; - } - else - { - PDEBUG("ip6_ip4(): cannot translate extention header = %d, packet dropped\n", next_hdr); - return -1; - } - } - } - } - else - { - PDEBUG("ip6_ip4(): error packet len, packet dropped.\n"); - return -1; - } - - /* Building ipv4 packet */ - - ip_hdr->version = IPVERSION; - ip_hdr->ihl = 5; - - /* TOS see comment about TOS in ip4_ip6() */ - if (tos_ignore_flag) - ip_hdr->tos = 0; - else { - ip_hdr->tos = ip6_hdr->priority << 4; - ip_hdr->tos = ip_hdr->tos | (ip6_hdr->flow_lbl[0] >> 4); - } - - /* IPv4 Total Len = IPv6 Payload Len + - IPv4 Header Len (without options) - Options Headers Len */ - ip6_payload_len = ntohs(ip6_hdr->payload_len); - - if (ip6_payload_len == 0) - ntot_len = 0; - else - ntot_len = ip6_payload_len + IP4_IP6_HDR_DIFF - opts_len; - - ip_hdr->tot_len = htons(ntot_len); - - /* IPv4 TTL = IPv6 Hop Limit */ - ip_hdr->ttl = ip6_hdr->hop_limit; - - /* IPv4 Protocol = Next Header that will point to upper layer protocol */ - ip_hdr->protocol = next_hdr; - - /* IPv4 Src addr = last 4 bytes from IPv6 Src addr */ - ip_hdr->saddr = ip6_hdr->saddr.s6_addr32[3]; - /* IPv4 Dst addr = last 4 bytes from IPv6 Dst addr */ - ip_hdr->daddr = ip6_hdr->daddr.s6_addr32[3]; - - /* Calculate IPv4 header checksum */ - ip_hdr->check = 0; - ip_hdr->check = ip_fast_csum((unsigned char *)ip_hdr, ip_hdr->ihl); - - if (len_delta > 0) - { - /* PROCESS ICMP */ - - if (next_hdr == NEXTHDR_ICMP) - { - struct icmp6hdr *icmp6_hdr; - struct icmphdr *icmp_hdr; - - if ((len_delta -= sizeof(struct icmp6hdr)) >= 0) - { - icmp6_hdr = (struct icmp6hdr *)(src + sizeof(struct ipv6hdr) + opts_len); - icmp_hdr = (struct icmphdr *)(dst + sizeof(struct iphdr)); - - real_len += len_delta + sizeof(struct icmphdr); - - /* There is diffirent between ICMPv4/ICMPv6 protocol codes - IPPROTO_ICMP = 1 - IPPROTO_ICMPV6 = 58 */ - ip_hdr->protocol = IPPROTO_ICMP; - - if (include_flag) { - /* !!! Warnig !!! We discard ICMP packets with any ICMP as included - in ICMP Error. But ICMP Error messages can include ICMP Query message - */ - if (icmp6_hdr->icmp6_type != ICMPV6_ECHO_REQUEST) - { - PDEBUG("ip6_ip4(): included ICMPv6 in ICMPv6 Error message, packet dropped\n"); - return -1; - } - } - - /* Translate ICMPv6 to ICMPv4 */ - switch (icmp6_hdr->icmp6_type) - { -/* ICMP Error messages */ - /* Destination Unreachable (Type 1) */ - case ICMPV6_DEST_UNREACH: /* Type 1 */ - icmp_hdr->type = ICMP_DEST_UNREACH; /* to Type 3 */ - icmp_hdr->un.echo.id = 0; - icmp_hdr->un.echo.sequence = 0; - switch (icmp6_hdr->icmp6_code) - { - case ICMPV6_NOROUTE: /* Code 0 */ - case ICMPV6_NOT_NEIGHBOUR: /* Code 2 */ - case ICMPV6_ADDR_UNREACH: /* Code 3 */ - icmp_hdr->code = ICMP_HOST_UNREACH; /* To Code 1 */ - break; - case ICMPV6_ADM_PROHIBITED: /* Code 1 */ - icmp_hdr->code = ICMP_HOST_ANO; /* To Code 10 */ - break; - case ICMPV6_PORT_UNREACH: /* Code 4 */ - icmp_hdr->code = ICMP_PORT_UNREACH; /* To Code 3 */ - - break; - default: /* discard any other codes */ - PDEBUG("ip6_ip4(): Unknown ICMPv6 Type %d Code %d - packet dropped.\n", - ICMPV6_DEST_UNREACH, icmp6_hdr->icmp6_code); - return -1; - } - break; - /* Packet Too Big (Type 2) */ - case ICMPV6_PKT_TOOBIG: /* Type 2 */ - icmp_hdr->type = ICMP_DEST_UNREACH; /* to Type 3 */ - icmp_hdr->code = ICMP_FRAG_NEEDED; /* to Code 4 */ - /* Change MTU, RFC 2765 (SIIT), 4.2: - The MTU field needs to be adjusted for the difference between - the IPv4 and IPv6 header sizes taking into account whether or - not the packet in error includes a Fragment header. - */ - /* !!! Don't implement !!! */ - icmp_hdr->un.frag.mtu = (__u16) icmp6_hdr->icmp6_mtu; - break; - /* Time Exceeded (Type 3) */ - case ICMPV6_TIME_EXCEED: - icmp_hdr->type = ICMP_TIME_EXCEEDED; /* to Type 11 */ - icmp_hdr->code = icmp6_hdr->icmp6_code; /* Code unchanged */ - break; - /* Parameter Problem (Type 4) */ - case ICMPV6_PARAMPROB: - switch (icmp6_hdr->icmp6_code) { - case ICMPV6_UNK_NEXTHDR: /* Code 1 */ - icmp_hdr->type = ICMP_DEST_UNREACH; /* to Type 3 */ - icmp_hdr->code = ICMP_PROT_UNREACH; /* to Code 2 */ - break; - default: /* if Code != 1 */ - icmp_hdr->type = ICMP_PARAMETERPROB; /* to Type 12 */ - icmp_hdr->code = 0; /* to Code 0 */ - /* Update Pointer field - RFC 2765 (SIIT), 4.2: - The Pointer needs to be updated to point to the corresponding - field in the translated include IP header. - */ - switch (ntohl(icmp6_hdr->icmp6_pointer)) - { - case 0: /* IPv6 Version -> IPv4 Version */ - icmp_hdr->un.echo.id = 0; - break; - case 4: /* IPv6 PayloadLength -> IPv4 Total Length */ - icmp_hdr->un.echo.id = 0x0002; /* 2 */ - break; - case 6: /* IPv6 Next Header-> IPv4 Protocol */ - icmp_hdr->un.echo.id = 0x0009; /* 9 */ - break; - case 7: /* IPv6 Hop Limit -> IPv4 TTL */ - icmp_hdr->un.echo.id = 0x0008; /* 8 */ - break; - case 8: /* IPv6 Src addr -> IPv4 Src addr */ - icmp_hdr->un.echo.id = 0x000c; /* 12 */ - break; - case 24: /* IPv6 Dst addr -> IPv4 Dst addr*/ - icmp_hdr->un.echo.id = 0x0010; /* 16 */ - break; - default: /* set all ones in other cases */ - icmp_hdr->un.echo.id = 0xff; - break; - } - break; - } - break; - -/* End of ICMP Error messages */ - - /* Echo Request and Echo Reply (Type 128 and 129) */ - case ICMPV6_ECHO_REQUEST: - icmperr = 0; /* not error ICMP message */ - icmp_hdr->type = ICMP_ECHO; /* to Type 8 */ - icmp_hdr->code = 0; /* to Code 0 */ - icmp_hdr->un.echo.id = icmp6_hdr->icmp6_identifier; - icmp_hdr->un.echo.sequence = icmp6_hdr->icmp6_sequence; - /* copy rest of ICMP data to result packet */ - if (len_delta > 0) - memcpy(((char *)icmp_hdr) + sizeof(struct icmphdr), - ((char *)icmp6_hdr) + sizeof(struct icmp6hdr), len_delta); - break; - case ICMPV6_ECHO_REPLY: - icmperr = 0; /* not error ICMP message */ - icmp_hdr->type = ICMP_ECHOREPLY; /* to Type 0 */ - icmp_hdr->code = 0; /* to Code 0 */ - icmp_hdr->un.echo.id = icmp6_hdr->icmp6_identifier; - icmp_hdr->un.echo.sequence = icmp6_hdr->icmp6_sequence; - /* copy rest of ICMP data */ - if (len_delta > 0) - memcpy(((char *)icmp_hdr) + sizeof(struct icmphdr), - ((char *)icmp6_hdr) + sizeof(struct icmp6hdr), len_delta); - break; - default: - /* Unknown error messages. Silently drop. */ - PDEBUG("ip6_ip4(): unknown ICMPv6 Type %d, packet dropped.\n", icmp6_hdr->icmp6_type); - return -1; - } - - if (icmperr) - { - /* If ICMP Error message, we translate IP included packet*/ - if (len_delta >= sizeof(struct ipv6hdr)) - { - if((inc_opts_len = ip6_ip4((char *)icmp6_hdr + sizeof(struct icmp6hdr), len_delta, - (char *)icmp_hdr + sizeof(struct icmphdr), 1)) == -1) { - PDEBUG("ip6_ip4(): incorrect translation of ICMPv6 Error message, packet dropped\n"); - return -1; - } - /* correct IPv4 Total Len that = old Total Len - - Options Headers Len in included IP packet - - diffirence between IPv6 Header Len and IPv4 Header Len - */ - if (ntot_len != 0) - ip_hdr->tot_len = htons(ntot_len - inc_opts_len - IP4_IP6_HDR_DIFF); - real_len = real_len - inc_opts_len - IP4_IP6_HDR_DIFF; - } - else if (len_delta > 0) - { - /* May be it need set 0x0 to rest area in result IPv4 packet, - * but we copy rest data unchanged - */ - memcpy(((char *)icmp_hdr) + sizeof(struct icmphdr), - ((char *)icmp6_hdr) + sizeof(struct icmp6hdr), len_delta); - } - } - - /* Calculate IPv4 Header checksum */ - ip_hdr->check = 0; - ip_hdr->check = ip_fast_csum((unsigned char *)ip_hdr, ip_hdr->ihl); - - /* Calculate ICMPv4 checksum */ - if (ntot_len != 0) - { - icmp_hdr->checksum = 0; - icmp_hdr->checksum = ip_compute_csum((unsigned char *)icmp_hdr, ntohs(ip_hdr->tot_len) - - sizeof(struct iphdr)); - } - } - else - { - PDEBUG("ip6_ip4(): error length ICMP packet, packet dropped.\n"); - return -1; - } - - } - /* PROCESS TCP and UDP (and rest data) */ - - else { - real_len += len_delta; - /* we copy rest data to IPv4 packet without changing */ - memcpy(dst+sizeof(struct iphdr), src + sizeof(struct ipv6hdr) + opts_len, len_delta); - } - } - - if (include_flag) /* if it's included IP packet */ - return opts_len; /* return options headers length */ - else - return real_len; /* result packet len */ -} - -/* - * ip4_fragment(skb, len, hdr_len, dev, eth_h) - * to fragment original IPv4 packet if result IPv6 packet will be > 1280 - */ - -static int ip4_fragment(struct sk_buff *skb, int len, int hdr_len, struct net_device *dev, struct ethhdr *eth_h) -{ - struct sk_buff *skb2 = NULL; /* pointer to new struct sk_buff for transleded packet */ - char buff[FRAG_BUFF_SIZE+hdr_len]; /* buffer to form new fragment packet */ - char *cur_ptr = skb->data+hdr_len; /* pointter to current packet data with len = frag_len */ - struct iphdr *ih4 = (struct iphdr *) skb->data; - struct iphdr *new_ih4 = (struct iphdr *) buff; /* point to new IPv4 hdr */ - struct ethhdr *new_eth_h; /* point to ether hdr, need to set hard header data in fragment */ - int data_len = len - hdr_len; /* origin packet data len */ - int rest_len = data_len; /* rest data to fragment */ - int frag_len = 0; /* current fragment len */ - int last_frag = 0; /* last fragment flag, if = 1, it's last fragment */ - int flag_last_mf = 0; - __u16 new_id = 0; /* to generate identification field */ - __u16 frag_offset = 0; /* fragment offset */ - unsigned int csum; - unsigned short udp_len; - -#ifdef SIIT_DEBUG - printk("siit: it's DF == 0 and result IPv6 packet will be > 1280\n"); - siit_print_dump(skb->data, hdr_len, "siit: (orig) ipv4_hdr dump"); -#endif - - if ((ntohs(ih4->frag_off) & IP_MF) == 0 ) - /* it's a case we'll clear MF flag in our last packet */ - flag_last_mf = 1; - - if (ih4->protocol == IPPROTO_UDP) { - if ( (ntohs(ih4->frag_off) & IP_OFFSET) == 0) { - struct udphdr *udp_hdr = (struct udphdr *)((char *)ih4 + hdr_len); - if (!flag_last_mf) { - if (udp_hdr->check == 0) { - /* it's a first fragment with ZERO checksum and we drop packet */ - printk("siit: First fragment of UDP with zero checksum - packet droped\n"); - printk("siit: addr: %x src port: %d dst port: %d\n", - htonl(ih4->saddr), htons(udp_hdr->source), htons(udp_hdr->dest)); - return -1; - } - } - else if (udp_hdr->check == 0) { - /* Calculate UDP checksum only if it's not fragment */ - udp_len = ntohs(udp_hdr->len); - csum = 0; - csum = csum_partial((unsigned char *)udp_hdr, udp_len, csum); - udp_hdr->check = csum_tcpudp_magic(ih4->saddr, ih4->daddr, udp_len, IPPROTO_UDP, csum); - } - } - } - - frag_offset = ntohs(ih4->frag_off) & IP_OFFSET; - - new_id = ih4->id; - - while(1) { - if (rest_len <= FRAG_BUFF_SIZE) { - /* it's last fragmen */ - frag_len = rest_len; /* rest data */ - last_frag = 1; - } - else - frag_len = FRAG_BUFF_SIZE; - - /* copy IP header to buffer */ - memcpy(buff, skb->data, hdr_len); - /* copy data to buffer with len = frag_len */ - memcpy(buff + hdr_len, cur_ptr, frag_len); - - /* set id field in new IPv4 header*/ - new_ih4->id = new_id; - - /* is it last fragmet */ - if(last_frag && flag_last_mf) - /* clear MF flag */ - new_ih4->frag_off = htons(frag_offset & (~IP_MF)); - else - /* set MF flag */ - new_ih4->frag_off = htons(frag_offset | IP_MF); - - /* change packet total length */ - new_ih4->tot_len = htons(frag_len+hdr_len); - - /* rebuild the header checksum (IP needs it) */ - new_ih4->check = 0; - new_ih4->check = ip_fast_csum((unsigned char *)new_ih4,new_ih4->ihl); - - /* Allocate new sk_buff to compose translated packet */ - skb2 = dev_alloc_skb(frag_len+hdr_len+dev->hard_header_len+IP4_IP6_HDR_DIFF+IP6_FRAGMENT_SIZE); - if (!skb2) { - printk(KERN_DEBUG "%s: alloc_skb failure - packet dropped.\n", dev->name); - dev_kfree_skb(skb2); - return -1; - } - /* allocate skb->data portion for IP header len, fragment data len and ether header len - * and copy to head ether header from origin skb - */ - memcpy(skb_put(skb2, frag_len+hdr_len+dev->hard_header_len+IP4_IP6_HDR_DIFF+IP6_FRAGMENT_SIZE), (char *) eth_h, - dev->hard_header_len); - /* correct ether header data, ether protocol field to ETH_P_IPV6 */ - new_eth_h = (struct ethhdr *)skb2->data; - new_eth_h->h_proto = htons(ETH_P_IPV6); - - /* reset the mac header */ - skb_reset_mac_header(skb2); - - /* pull ether header from new skb->data */ - skb_pull(skb2, dev->hard_header_len); - /* set skb protocol to IPV6 */ - skb2->protocol = htons(ETH_P_IPV6); - - /* call translation function */ - if ( ip4_ip6(buff, frag_len+hdr_len, skb2->data, 0) == -1) { - dev_kfree_skb(skb2); - return -1; - } - - /* - * Set needed fields in new sk_buff - */ - skb2->dev = dev; - skb2->ip_summed = CHECKSUM_UNNECESSARY; - skb2->pkt_type = PACKET_HOST; - - /* Add transmit statistic */ - siit_stats(dev)->tx_packets++; - siit_stats(dev)->tx_bytes += skb2->len; - - /* send packet to upper layer */ - netif_rx(skb2); - - /* exit if it was last fragment */ - if (last_frag) - break; - - /* correct current data pointer */ - cur_ptr += frag_len; - /* rest data len */ - rest_len -= frag_len; - /* current fragment offset */ - frag_offset = (frag_offset*8 + frag_len)/8; - } - - return 0; -} -/* - * Transmit a packet (called by the kernel) - * - * siit_xmit(skb, dev) - * - * where - * skb - pointer to struct sk_buff with incomed packet - * dev - pointer to struct device on which packet revieved - * - * Statistic: - * for all incoming packes: - * stats.rx_bytes+=skb->len - * stats.rx_packets++ - * for packets we can't transle: - * stats.tx_errors++ - * device busy: - * stats.tx_errors++ - * for packets we can't allocate sk_buff: - * stats.tx_dropped++ - * for outgoing packes: - * stats.tx_packets++ - * stats.tx_bytes+=skb2->len !!! But we don't set skb2->len !!! - */ - -static int siit_xmit(struct sk_buff *skb, struct net_device *dev) -{ - struct sk_buff *skb2 = NULL;/* pointer to new struct sk_buff for transleded packet */ - struct ethhdr *eth_h; /* pointer to incoming Ether header */ - int len; /* original packets length */ - int new_packet_len; - int skb_delta = 0; /* delta size for allocate new skb */ - char new_packet_buff[2048]; - - /* Check pointer to sk_buff and device structs */ - if (skb == NULL || dev == NULL) - return -EINVAL; - - /* Add receive statistic */ - siit_stats(dev)->rx_bytes += skb->len; - siit_stats(dev)->rx_packets++; - - dev->trans_start = jiffies; - - /* Upper layer (IP) protocol forms sk_buff for outgoing packet - * and sets IP header + Ether header too. IP layer sets outgoing - * device in sk_buff->dev. - * In function (from linux/net/core/dev.c) ther is a call to - * device transmit function (dev->hard_start_xmit): - * - * dev_queue_xmit(struct sk_buff *skb) - * { - * ... - * device *dev = skb->dev; - * ... - * dev->hard_start_xmit(skb, dev); - * ... - * } - * We save pointer to ether header in eth_h and skb_pull ether header - * from data field of skb_buff - */ - - eth_h = (struct ethhdr *)skb->data; /* point to incoming packet Ether Header */ - -#ifdef SIIT_DEBUG - siit_print_dump(skb->data, ETH_HLEN, "siit: eth_hdr dump"); -#endif - - /* Remove hardware header from origin sk_buff */ - skb_pull(skb,dev->hard_header_len); - - /* - * Process IPv4 paket - */ - if (ntohs(skb->protocol) == ETH_P_IP) { - int hdr_len; /* IPv4 header length */ - int data_len; /* IPv4 data length */ - struct iphdr *ih4; /* pointer to IPv4 header */ - struct icmphdr *icmp_hdr; /* point to current ICMPv4 header struct */ - - ih4 = (struct iphdr *)skb->data; /* point to incoming packet's IPv4 header */ - - /* Check IPv4 Total Length */ - if (skb->len != ntohs(ih4->tot_len)) { - PDEBUG("siit_xmit(): Different skb_len %x and ip4 tot_len %x - packet dropped.\n", - skb->len, ih4->tot_len); - siit_stats(dev)->tx_errors++; - dev_kfree_skb(skb); - return 0; - } - - len = skb->len; /* packet's total len */ - hdr_len = (int)(ih4->ihl * 4); /* packet's header len */ - data_len = len - hdr_len; /* packet's data len */ - - /* If DF == 0 */ - if ( (ntohs(ih4->frag_off) & IP_DF) == 0 ) { - /* If result IPv6 packet will be > 1280 - we need to fragment original IPv4 packet - */ - if ( data_len > FRAG_BUFF_SIZE ) { - /* call function that fragment packet and translate to IPv6 each fragment - * and send to upper layer - */ - if ( ip4_fragment(skb, len, hdr_len, dev, eth_h) == -1) { - siit_stats(dev)->tx_errors++; - } - /* Free incoming skb */ - dev_kfree_skb(skb); - /* Device can accept a new packet */ - - return 0; - - } - } - /* If DF == 1 && MF == 0 && Fragment Offset == 0 - * we don't include fragment header - */ - if ( ntohs(ih4->frag_off) == IP_DF ) - skb_delta = IP4_IP6_HDR_DIFF; /* delta is +20 */ - else - skb_delta = IP4_IP6_HDR_DIFF + IP6_FRAGMENT_SIZE; /* delta is +20 and +8 */ - - /* If it's ICMP, check is it included IP packet in it */ - if ( ih4->protocol == IPPROTO_ICMP) { - icmp_hdr = (struct icmphdr *) (skb->data+hdr_len); /* point to ICMPv4 header */ - if ( icmp_hdr->type != ICMP_ECHO && icmp_hdr->type != ICMP_ECHOREPLY) { - /* - * It's ICMP Error that has included IP packet - * we'll add only +20 because we don't include Fragment Header - * into translated included IP packet - */ - skb_delta += IP4_IP6_HDR_DIFF; - } - } - - /* Allocate new sk_buff to compose translated packet */ - skb2 = dev_alloc_skb(len+dev->hard_header_len+skb_delta); - if (!skb2) { - printk(KERN_DEBUG "%s: alloc_skb failure - packet dropped.\n", dev->name); - dev_kfree_skb(skb); - siit_stats(dev)->rx_dropped++; - - return 0; - } - /* allocate skb->data portion = IPv4 packet len + ether header len - * + skb_delta (max = two times (diffirence between IPv4 header and - * IPv6 header + Frag Header), second for included packet, - * and copy to head of skb->data ether header from origin skb - */ - memcpy(skb_put(skb2, len+dev->hard_header_len+skb_delta), (char *)eth_h, dev->hard_header_len); - /* correct ether header data, ether protocol field to ETH_P_IPV6 */ - eth_h = (struct ethhdr *)skb2->data; - eth_h->h_proto = htons(ETH_P_IPV6); - skb_reset_mac_header(skb2); - /* remove ether header from new skb->data, - * NOTE! data will rest, pointer to data and data len will change - */ - skb_pull(skb2,dev->hard_header_len); - /* set skb protocol to IPV6 */ - skb2->protocol = htons(ETH_P_IPV6); - - /* call translation function */ - if (ip4_ip6(skb->data, len, skb2->data, 0) == -1 ) { - dev_kfree_skb(skb); - dev_kfree_skb(skb2); - siit_stats(dev)->rx_errors++; - - return 0; - } - } - /* - * IPv6 paket - */ - else if (ntohs(skb->protocol) == ETH_P_IPV6) { - -#ifdef SIIT_DEBUG - siit_print_dump(skb->data, sizeof(struct ipv6hdr), "siit: (in) ip6_hdr dump"); -#endif - /* packet len = skb->data len*/ - len = skb->len; - - /* call translation function */ - if ((new_packet_len = ip6_ip4(skb->data, len, new_packet_buff, 0)) == -1 ) - { - PDEBUG("siit_xmit(): error translation ipv6->ipv4, packet dropped.\n"); - siit_stats(dev)->rx_dropped++; - goto end; - } - - /* Allocate new sk_buff to compose translated packet */ - skb2 = dev_alloc_skb(new_packet_len + dev->hard_header_len); - if (!skb2) { - printk(KERN_DEBUG "%s: alloc_skb failure, packet dropped.\n", dev->name); - siit_stats(dev)->rx_dropped++; - goto end; - } - memcpy(skb_put(skb2, new_packet_len + dev->hard_header_len), (char *)eth_h, dev->hard_header_len); - eth_h = (struct ethhdr *)skb2->data; - eth_h->h_proto = htons(ETH_P_IP); - skb_reset_mac_header(skb2); - skb_pull(skb2, dev->hard_header_len); - memcpy(skb2->data, new_packet_buff, new_packet_len); - skb2->protocol = htons(ETH_P_IP); - } - else { - PDEBUG("siit_xmit(): unsupported protocol family %x, packet dropped.\n", skb->protocol); - goto end; - } - - /* - * Set needed fields in new sk_buff - */ - skb2->pkt_type = PACKET_HOST; - skb2->dev = dev; - skb2->ip_summed = CHECKSUM_UNNECESSARY; - - /* Add transmit statistic */ - siit_stats(dev)->tx_packets++; - siit_stats(dev)->tx_bytes += skb2->len; - - /* Send packet to upper layer protocol */ - netif_rx(skb2); - -end: - dev_kfree_skb(skb); - - return 0; -} - -#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,0) -static bool header_ops_init = false; -static struct header_ops siit_header_ops ____cacheline_aligned; -#endif - -#if !(defined CONFIG_COMPAT_NET_DEV_OPS) && LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,30) -static const struct net_device_ops siit_netdev_ops = { - .ndo_open = siit_open, - .ndo_stop = siit_release, - .ndo_start_xmit = siit_xmit, -}; -#endif - -/* - * The init function initialize of the SIIT device.. - * It is invoked by register_netdev() - */ - -static void -siit_init(struct net_device *dev) -{ - ether_setup(dev); /* assign some of the fields */ - random_ether_addr(dev->dev_addr); - - /* - * Assign device function. - */ -#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,30) - dev->open = siit_open; - dev->stop = siit_release; - dev->hard_start_xmit = siit_xmit; -#else -#if !(defined CONFIG_COMPAT_NET_DEV_OPS) && LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,30) - dev->netdev_ops = &siit_netdev_ops; -#endif -#endif - dev->flags |= IFF_NOARP; /* ARP not used */ - dev->tx_queue_len = 10; - -#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0) - dev->hard_header_cache = NULL; /* Disable caching */ - memset(netdev_priv(dev), 0, sizeof(struct net_device_stats)); - dev->get_stats = siit_get_stats; -#else - if (!header_ops_init) { - memcpy(&siit_header_ops, dev->header_ops, sizeof(struct header_ops)); - siit_header_ops.cache = NULL; - } - dev->header_ops = &siit_header_ops; -#endif -} - -/* - * Finally, the module stuff - */ -static struct net_device *siit_dev = NULL; - -int init_module(void) -{ - int res = -ENOMEM; - int priv_size; - -#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0) - priv_size = sizeof(struct net_device_stats); -#else - priv_size = sizeof(struct header_ops); -#endif - siit_dev = alloc_netdev(priv_size, "siit%d", siit_init); - if (!siit_dev) - goto err_alloc; - - res = register_netdev(siit_dev); - if (res) - goto err_register; - - return 0; - -err_register: - free_netdev(siit_dev); -err_alloc: - printk(KERN_ERR "Error creating siit device: %d\n", res); - return res; -} - -void cleanup_module(void) -{ - unregister_netdev(siit_dev); - free_netdev(siit_dev); -} - - |