From mboxrd@z Thu Jan 1 00:00:00 1970 From: Patrick McHardy Subject: [PATCH 2.6 4/19]: Enable ip6t_LOG.c to work without skb_linearize() Date: Mon, 25 Oct 2004 02:48:58 +0200 Sender: netfilter-devel-bounces@lists.netfilter.org Message-ID: <417C4D7A.8090508@trash.net> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="------------070607040905090101040407" Cc: Netfilter Development Mailinglist Return-path: To: "David S. Miller" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: netfilter-devel-bounces@lists.netfilter.org List-Id: netfilter-devel.vger.kernel.org This is a multi-part message in MIME format. --------------070607040905090101040407 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Convert ip6t_LOG to skb_header_pointer, fix multiple bugs. --------------070607040905090101040407 Content-Type: text/x-patch; name="04.diff" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="04.diff" # This is a BitKeeper generated diff -Nru style patch. # # ChangeSet # 2004/10/19 02:15:21+02:00 yasuyuki.kozakai@toshiba.co.jp # [NETFILTER]: Enable ip6t_LOG.c to work without skb_linearize() # # This patch enables ip6t_LOG.c to work without skb_linearize(). # # I changed a large part of this file. At first, ip6_nexthdr() is deleted # to prevent multiple call of skb_header_pointer() at dump_packet() and # ip6_nexthdr(). # # And the following bugs are fixed. The first bug is fixed by introducing # skb_header_pointer(), then I didn't separate patches. # # - No check with skb->len. Then invalid memory access may occur. # # - If packet is fragmented and it's not first fragment, nonexistent # extension headers is tried to parse. # # - All headers which aren't TCP/UDP/ICMPv6 are treated as IPv6 # extension header. # # - The encrypted data after ESP is tried to parse. # # - ntohl() for ID in Fragment header is missing. # # - If doff*4 of TCP header is less than sizeof(struct tcphdr), # TCP options are tried to parse. # # Signed-off-by: Yasuyuki KOZAKAI # Signed-off-by: Patrick McHardy # # net/ipv6/netfilter/ip6t_LOG.c # 2004/10/19 02:14:54+02:00 yasuyuki.kozakai@toshiba.co.jp +178 -99 # [NETFILTER]: Enable ip6t_LOG.c to work without skb_linearize() # # This patch enables ip6t_LOG.c to work without skb_linearize(). # # I changed a large part of this file. At first, ip6_nexthdr() is deleted # to prevent multiple call of skb_header_pointer() at dump_packet() and # ip6_nexthdr(). # # And the following bugs are fixed. The first bug is fixed by introducing # skb_header_pointer(), then I didn't separate patches. # # - No check with skb->len. Then invalid memory access may occur. # # - If packet is fragmented and it's not first fragment, nonexistent # extension headers is tried to parse. # # - All headers which aren't TCP/UDP/ICMPv6 are treated as IPv6 # extension header. # # - The encrypted data after ESP is tried to parse. # # - ntohl() for ID in Fragment header is missing. # # - If doff*4 of TCP header is less than sizeof(struct tcphdr), # TCP options are tried to parse. # # Signed-off-by: Yasuyuki KOZAKAI # Signed-off-by: Patrick McHardy # diff -Nru a/net/ipv6/netfilter/ip6t_LOG.c b/net/ipv6/netfilter/ip6t_LOG.c --- a/net/ipv6/netfilter/ip6t_LOG.c 2004-10-22 03:37:43 +02:00 +++ b/net/ipv6/netfilter/ip6t_LOG.c 2004-10-22 03:37:43 +02:00 @@ -40,120 +40,166 @@ #define DEBUGP(format, args...) #endif -struct esphdr { - __u32 spi; -}; /* FIXME evil kludge */ - /* Use lock to serialize, so printks don't overlap */ static spinlock_t log_lock = SPIN_LOCK_UNLOCKED; -/* takes in current header and pointer to the header */ -/* if another header exists, sets hdrptr to the next header - and returns the new header value, else returns IPPROTO_NONE */ -static u_int8_t ip6_nexthdr(u_int8_t currenthdr, u_int8_t **hdrptr) -{ - u_int8_t hdrlen, nexthdr = IPPROTO_NONE; - - switch(currenthdr){ - case IPPROTO_AH: - /* whoever decided to do the length of AUTH for ipv6 - in 32bit units unlike other headers should be beaten... - repeatedly...with a large stick...no, an even LARGER - stick...no, you're still not thinking big enough */ - nexthdr = **hdrptr; - hdrlen = (*hdrptr)[1] * 4 + 8; - *hdrptr = *hdrptr + hdrlen; - break; - /*stupid rfc2402 */ - case IPPROTO_DSTOPTS: - case IPPROTO_ROUTING: - case IPPROTO_HOPOPTS: - nexthdr = **hdrptr; - hdrlen = (*hdrptr)[1] * 8 + 8; - *hdrptr = *hdrptr + hdrlen; - break; - case IPPROTO_FRAGMENT: - nexthdr = **hdrptr; - *hdrptr = *hdrptr + 8; - break; - } - return nexthdr; -} - /* One level of recursion won't kill us */ static void dump_packet(const struct ip6t_log_info *info, - struct ipv6hdr *ipv6h, int recurse) + const struct sk_buff *skb, unsigned int ip6hoff, + int recurse) { - u_int8_t currenthdr = ipv6h->nexthdr; - u_int8_t *hdrptr; + u_int8_t currenthdr; int fragment; + struct ipv6hdr _ip6h, *ih; + unsigned int ptr; + unsigned int hdrlen = 0; + + ih = skb_header_pointer(skb, ip6hoff, sizeof(_ip6h), &_ip6h); + if (ih == NULL) { + printk("TRUNCATED"); + return; + } /* Max length: 88 "SRC=0000.0000.0000.0000.0000.0000.0000.0000 DST=0000.0000.0000.0000.0000.0000.0000.0000" */ - printk("SRC=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(ipv6h->saddr)); - printk("DST=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(ipv6h->daddr)); + printk("SRC=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(ih->saddr)); + printk("DST=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(ih->daddr)); /* Max length: 44 "LEN=65535 TC=255 HOPLIMIT=255 FLOWLBL=FFFFF " */ printk("LEN=%Zu TC=%u HOPLIMIT=%u FLOWLBL=%u ", - ntohs(ipv6h->payload_len) + sizeof(struct ipv6hdr), - (ntohl(*(u_int32_t *)ipv6h) & 0x0ff00000) >> 20, - ipv6h->hop_limit, - (ntohl(*(u_int32_t *)ipv6h) & 0x000fffff)); + ntohs(ih->payload_len) + sizeof(struct ipv6hdr), + (ntohl(*(u_int32_t *)ih) & 0x0ff00000) >> 20, + ih->hop_limit, + (ntohl(*(u_int32_t *)ih) & 0x000fffff)); fragment = 0; - hdrptr = (u_int8_t *)(ipv6h + 1); - while (currenthdr != IPPROTO_NONE) { - if ((currenthdr == IPPROTO_TCP) || - (currenthdr == IPPROTO_UDP) || - (currenthdr == IPPROTO_ICMPV6)) - break; + ptr = ip6hoff + sizeof(struct ipv6hdr); + currenthdr = ih->nexthdr; + while (currenthdr != NEXTHDR_NONE && ip6t_ext_hdr(currenthdr)) { + struct ipv6_opt_hdr _hdr, *hp; + + hp = skb_header_pointer(skb, ptr, sizeof(_hdr), &_hdr); + if (hp == NULL) { + printk("TRUNCATED"); + return; + } + /* Max length: 48 "OPT (...) " */ - printk("OPT ( "); + if (info->logflags & IP6T_LOG_IPOPT) + printk("OPT ( "); + switch (currenthdr) { case IPPROTO_FRAGMENT: { - struct frag_hdr *fhdr = (struct frag_hdr *)hdrptr; + struct frag_hdr _fhdr, *fh; - /* Max length: 11 "FRAG:65535 " */ - printk("FRAG:%u ", ntohs(fhdr->frag_off) & 0xFFF8); + printk("FRAG:"); + fh = skb_header_pointer(skb, ptr, sizeof(_fhdr), + &_fhdr); + if (fh == NULL) { + printk("TRUNCATED "); + return; + } + + /* Max length: 6 "65535 " */ + printk("%u ", ntohs(fh->frag_off) & 0xFFF8); /* Max length: 11 "INCOMPLETE " */ - if (fhdr->frag_off & htons(0x0001)) + if (fh->frag_off & htons(0x0001)) printk("INCOMPLETE "); - printk("ID:%08x ", fhdr->identification); + printk("ID:%08x ", ntohl(fh->identification)); - if (ntohs(fhdr->frag_off) & 0xFFF8) + if (ntohs(fh->frag_off) & 0xFFF8) fragment = 1; + hdrlen = 8; + break; } case IPPROTO_DSTOPTS: case IPPROTO_ROUTING: case IPPROTO_HOPOPTS: + if (fragment) { + if (info->logflags & IP6T_LOG_IPOPT) + printk(")"); + return; + } + hdrlen = ipv6_optlen(hp); break; /* Max Length */ case IPPROTO_AH: + if (info->logflags & IP6T_LOG_IPOPT) { + struct ip_auth_hdr _ahdr, *ah; + + /* Max length: 3 "AH " */ + printk("AH "); + + if (fragment) { + printk(")"); + return; + } + + ah = skb_header_pointer(skb, ptr, sizeof(_ahdr), + &_ahdr); + if (ah == NULL) { + /* + * Max length: 26 "INCOMPLETE [65535 + * bytes] )" + */ + printk("INCOMPLETE [%u bytes] )", + skb->len - ptr); + return; + } + + /* Length: 15 "SPI=0xF1234567 */ + printk("SPI=0x%x ", ntohl(ah->spi)); + + } + + hdrlen = (hp->hdrlen+2)<<2; + break; case IPPROTO_ESP: if (info->logflags & IP6T_LOG_IPOPT) { - struct esphdr *esph = (struct esphdr *)hdrptr; - int esp = (currenthdr == IPPROTO_ESP); + struct ip_esp_hdr _esph, *eh; /* Max length: 4 "ESP " */ - printk("%s ",esp ? "ESP" : "AH"); + printk("ESP "); + + if (fragment) { + printk(")"); + return; + } + + /* + * Max length: 26 "INCOMPLETE [65535 bytes] )" + */ + eh = skb_header_pointer(skb, ptr, sizeof(_esph), + &_esph); + if (eh == NULL) { + printk("INCOMPLETE [%u bytes] )", + skb->len - ptr); + return; + } + + /* Length: 16 "SPI=0xF1234567 )" */ + printk("SPI=0x%x )", ntohl(eh->spi) ); - /* Length: 15 "SPI=0xF1234567 " */ - printk("SPI=0x%x ", ntohl(esph->spi) ); - break; } + return; default: - break; + /* Max length: 20 "Unknown Ext Hdr 255" */ + printk("Unknown Ext Hdr %u", currenthdr); + return; } - printk(") "); - currenthdr = ip6_nexthdr(currenthdr, &hdrptr); + if (info->logflags & IP6T_LOG_IPOPT) + printk(") "); + + currenthdr = hp->nexthdr; + ptr += hdrlen; } switch (currenthdr) { case IPPROTO_TCP: { - struct tcphdr *tcph = (struct tcphdr *)hdrptr; + struct tcphdr _tcph, *th; /* Max length: 10 "PROTO=TCP " */ printk("PROTO=TCP "); @@ -161,51 +207,69 @@ if (fragment) break; + /* Max length: 25 "INCOMPLETE [65535 bytes] " */ + th = skb_header_pointer(skb, ptr, sizeof(_tcph), &_tcph); + if (th == NULL) { + printk("INCOMPLETE [%u bytes] ", skb->len - ptr); + return; + } + /* Max length: 20 "SPT=65535 DPT=65535 " */ printk("SPT=%u DPT=%u ", - ntohs(tcph->source), ntohs(tcph->dest)); + ntohs(th->source), ntohs(th->dest)); /* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */ if (info->logflags & IP6T_LOG_TCPSEQ) printk("SEQ=%u ACK=%u ", - ntohl(tcph->seq), ntohl(tcph->ack_seq)); + ntohl(th->seq), ntohl(th->ack_seq)); /* Max length: 13 "WINDOW=65535 " */ - printk("WINDOW=%u ", ntohs(tcph->window)); - /* Max length: 9 "RES=0x3F " */ - printk("RES=0x%02x ", (u_int8_t)(ntohl(tcp_flag_word(tcph) & TCP_RESERVED_BITS) >> 22)); + printk("WINDOW=%u ", ntohs(th->window)); + /* Max length: 9 "RES=0x3C " */ + printk("RES=0x%02x ", (u_int8_t)(ntohl(tcp_flag_word(th) & TCP_RESERVED_BITS) >> 22)); /* Max length: 32 "CWR ECE URG ACK PSH RST SYN FIN " */ - if (tcph->cwr) + if (th->cwr) printk("CWR "); - if (tcph->ece) + if (th->ece) printk("ECE "); - if (tcph->urg) + if (th->urg) printk("URG "); - if (tcph->ack) + if (th->ack) printk("ACK "); - if (tcph->psh) + if (th->psh) printk("PSH "); - if (tcph->rst) + if (th->rst) printk("RST "); - if (tcph->syn) + if (th->syn) printk("SYN "); - if (tcph->fin) + if (th->fin) printk("FIN "); /* Max length: 11 "URGP=65535 " */ - printk("URGP=%u ", ntohs(tcph->urg_ptr)); + printk("URGP=%u ", ntohs(th->urg_ptr)); if ((info->logflags & IP6T_LOG_TCPOPT) - && tcph->doff * 4 != sizeof(struct tcphdr)) { + && th->doff * 4 > sizeof(struct tcphdr)) { + u_int8_t _opt[60 - sizeof(struct tcphdr)], *op; unsigned int i; + unsigned int optsize = th->doff * 4 + - sizeof(struct tcphdr); + + op = skb_header_pointer(skb, + ptr + sizeof(struct tcphdr), + optsize, _opt); + if (op == NULL) { + printk("OPT (TRUNCATED)"); + return; + } /* Max length: 127 "OPT (" 15*4*2chars ") " */ printk("OPT ("); - for (i =sizeof(struct tcphdr); i < tcph->doff * 4; i++) - printk("%02X", ((u_int8_t *)tcph)[i]); + for (i =0; i < optsize; i++) + printk("%02X", op[i]); printk(") "); } break; } case IPPROTO_UDP: { - struct udphdr *udph = (struct udphdr *)hdrptr; + struct udphdr _udph, *uh; /* Max length: 10 "PROTO=UDP " */ printk("PROTO=UDP "); @@ -213,14 +277,21 @@ if (fragment) break; + /* Max length: 25 "INCOMPLETE [65535 bytes] " */ + uh = skb_header_pointer(skb, ptr, sizeof(_udph), &_udph); + if (uh == NULL) { + printk("INCOMPLETE [%u bytes] ", skb->len - ptr); + return; + } + /* Max length: 20 "SPT=65535 DPT=65535 " */ printk("SPT=%u DPT=%u LEN=%u ", - ntohs(udph->source), ntohs(udph->dest), - ntohs(udph->len)); + ntohs(uh->source), ntohs(uh->dest), + ntohs(uh->len)); break; } case IPPROTO_ICMPV6: { - struct icmp6hdr *icmp6h = (struct icmp6hdr *)hdrptr; + struct icmp6hdr _icmp6h, *ic; /* Max length: 13 "PROTO=ICMPv6 " */ printk("PROTO=ICMPv6 "); @@ -228,16 +299,23 @@ if (fragment) break; + /* Max length: 25 "INCOMPLETE [65535 bytes] " */ + ic = skb_header_pointer(skb, ptr, sizeof(_icmp6h), &_icmp6h); + if (ic == NULL) { + printk("INCOMPLETE [%u bytes] ", skb->len - ptr); + return; + } + /* Max length: 18 "TYPE=255 CODE=255 " */ - printk("TYPE=%u CODE=%u ", icmp6h->icmp6_type, icmp6h->icmp6_code); + printk("TYPE=%u CODE=%u ", ic->icmp6_type, ic->icmp6_code); - switch (icmp6h->icmp6_type) { + switch (ic->icmp6_type) { case ICMPV6_ECHO_REQUEST: case ICMPV6_ECHO_REPLY: /* Max length: 19 "ID=65535 SEQ=65535 " */ printk("ID=%u SEQ=%u ", - ntohs(icmp6h->icmp6_identifier), - ntohs(icmp6h->icmp6_sequence)); + ntohs(ic->icmp6_identifier), + ntohs(ic->icmp6_sequence)); break; case ICMPV6_MGM_QUERY: case ICMPV6_MGM_REPORT: @@ -246,7 +324,7 @@ case ICMPV6_PARAMPROB: /* Max length: 17 "POINTER=ffffffff " */ - printk("POINTER=%08x ", ntohl(icmp6h->icmp6_pointer)); + printk("POINTER=%08x ", ntohl(ic->icmp6_pointer)); /* Fall through */ case ICMPV6_DEST_UNREACH: case ICMPV6_PKT_TOOBIG: @@ -254,13 +332,14 @@ /* Max length: 3+maxlen */ if (recurse) { printk("["); - dump_packet(info, (struct ipv6hdr *)(icmp6h + 1), 0); + dump_packet(info, skb, ptr + sizeof(_icmp6h), + 0); printk("] "); } /* Max length: 10 "MTU=65535 " */ - if (icmp6h->icmp6_type == ICMPV6_PKT_TOOBIG) - printk("MTU=%u ", ntohl(icmp6h->icmp6_mtu)); + if (ic->icmp6_type == ICMPV6_PKT_TOOBIG) + printk("MTU=%u ", ntohl(ic->icmp6_mtu)); } break; } @@ -328,7 +407,7 @@ printk(" "); } - dump_packet(loginfo, ipv6h, 1); + dump_packet(loginfo, skb, (u8*)skb->nh.ipv6h - skb->data, 1); printk("\n"); spin_unlock_bh(&log_lock); } --------------070607040905090101040407--