Skip to content

L
linux
Commit 8bd22e22 authored by Yasuyuki Kozakai's avatar Yasuyuki Kozakai Committed by Patrick McHardy
Browse files
Options

[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: default avatarYasuyuki KOZAKAI <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
parent 5c1ee973
Hide whitespace changes
Inline Side-by-side
Showing with 178 additions and 99 deletions
net/ipv6/netfilter/ip6t_LOG.c
View file @ 8bd22e22
......@@ -40,120 +40,166 @@ struct in_device;
#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;
printk("FRAG:");
fh = skb_header_pointer(skb, ptr, sizeof(_fhdr),
&_fhdr);
if (fh == NULL) {
printk("TRUNCATED ");
return;
}
/* Max length: 11 "FRAG:65535 " */
printk("FRAG:%u ", ntohs(fhdr->frag_off) & 0xFFF8);
/* 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 @@ static void dump_packet(const struct ip6t_log_info *info,
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 @@ static void dump_packet(const struct ip6t_log_info *info,
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 @@ static void dump_packet(const struct ip6t_log_info *info,
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 @@ static void dump_packet(const struct ip6t_log_info *info,
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 @@ static void dump_packet(const struct ip6t_log_info *info,
/* 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 @@ ip6t_log_packet(unsigned int hooknum,
printk(" ");
}
dump_packet(loginfo, ipv6h, 1);
dump_packet(loginfo, skb, (u8*)skb->nh.ipv6h - skb->data, 1);
printk("\n");
spin_unlock_bh(&log_lock);
}
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7