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tcp md5sig: Share MD5 Signature option parser between IPv4 and IPv6.

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Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
This commit is contained in:
YOSHIFUJI Hideaki 2008-04-17 12:29:53 +09:00
parent 81b302a321
commit 7d5d5525bd
4 changed files with 44 additions and 73 deletions
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2
include/net/tcp.h
View File

@ -399,6 +399,8 @@ extern void tcp_parse_options(struct sk_buff *skb,
struct tcp_options_received *opt_rx,
int estab);
extern u8 *tcp_parse_md5sig_option(struct tcphdr *th);
/*
* TCP v4 functions exported for the inet6 API
*/

40
net/ipv4/tcp_input.c
View File

@ -3450,6 +3450,43 @@ static int tcp_fast_parse_options(struct sk_buff *skb, struct tcphdr *th,
return 1;
}
#ifdef CONFIG_TCP_MD5SIG
/*
* Parse MD5 Signature option
*/
u8 *tcp_parse_md5sig_option(struct tcphdr *th)
{
int length = (th->doff << 2) - sizeof (*th);
u8 *ptr = (u8*)(th + 1);
/* If the TCP option is too short, we can short cut */
if (length < TCPOLEN_MD5SIG)
return NULL;
while (length > 0) {
int opcode = *ptr++;
int opsize;
switch(opcode) {
case TCPOPT_EOL:
return NULL;
case TCPOPT_NOP:
length--;
continue;
default:
opsize = *ptr++;
if (opsize < 2 || opsize > length)
return NULL;
if (opcode == TCPOPT_MD5SIG)
return ptr;
}
ptr += opsize - 2;
length -= opsize;
}
return NULL;
}
#endif
static inline void tcp_store_ts_recent(struct tcp_sock *tp)
{
tp->rx_opt.ts_recent = tp->rx_opt.rcv_tsval;
@ -5467,6 +5504,9 @@ EXPORT_SYMBOL(sysctl_tcp_ecn);
EXPORT_SYMBOL(sysctl_tcp_reordering);
EXPORT_SYMBOL(sysctl_tcp_adv_win_scale);
EXPORT_SYMBOL(tcp_parse_options);
#ifdef CONFIG_TCP_MD5SIG
EXPORT_SYMBOL(tcp_parse_md5sig_option);
#endif
EXPORT_SYMBOL(tcp_rcv_established);
EXPORT_SYMBOL(tcp_rcv_state_process);
EXPORT_SYMBOL(tcp_initialize_rcv_mss);

42
net/ipv4/tcp_ipv4.c
View File

@ -1134,52 +1134,12 @@ static int tcp_v4_inbound_md5_hash(struct sock *sk, struct sk_buff *skb)
struct tcp_md5sig_key *hash_expected;
const struct iphdr *iph = ip_hdr(skb);
struct tcphdr *th = tcp_hdr(skb);
int length = (th->doff << 2) - sizeof(struct tcphdr);
int genhash;
unsigned char *ptr;
unsigned char newhash[16];
hash_expected = tcp_v4_md5_do_lookup(sk, iph->saddr);
hash_location = tcp_parse_md5sig_option(th);
/*
* If the TCP option length is less than the TCP_MD5SIG
* option length, then we can shortcut
*/
if (length < TCPOLEN_MD5SIG) {
if (hash_expected)
return 1;
else
return 0;
}
/* Okay, we can't shortcut - we have to grub through the options */
ptr = (unsigned char *)(th + 1);
while (length > 0) {
int opcode = *ptr++;
int opsize;
switch (opcode) {
case TCPOPT_EOL:
goto done_opts;
case TCPOPT_NOP:
length--;
continue;
default:
opsize = *ptr++;
if (opsize < 2)
goto done_opts;
if (opsize > length)
goto done_opts;
if (opcode == TCPOPT_MD5SIG) {
hash_location = ptr;
goto done_opts;
}
}
ptr += opsize-2;
length -= opsize;
}
done_opts:
/* We've parsed the options - do we have a hash? */
if (!hash_expected && !hash_location)
return 0;

33
net/ipv6/tcp_ipv6.c
View File

@ -844,43 +844,12 @@ static int tcp_v6_inbound_md5_hash (struct sock *sk, struct sk_buff *skb)
struct tcp_md5sig_key *hash_expected;
struct ipv6hdr *ip6h = ipv6_hdr(skb);
struct tcphdr *th = tcp_hdr(skb);
int length = (th->doff << 2) - sizeof (*th);
int genhash;
u8 *ptr;
u8 newhash[16];
hash_expected = tcp_v6_md5_do_lookup(sk, &ip6h->saddr);
hash_location = tcp_parse_md5sig_option(th);
/* If the TCP option is too short, we can short cut */
if (length < TCPOLEN_MD5SIG)
return hash_expected ? 1 : 0;
/* parse options */
ptr = (u8*)(th + 1);
while (length > 0) {
int opcode = *ptr++;
int opsize;
switch(opcode) {
case TCPOPT_EOL:
goto done_opts;
case TCPOPT_NOP:
length--;
continue;
default:
opsize = *ptr++;
if (opsize < 2 || opsize > length)
goto done_opts;
if (opcode == TCPOPT_MD5SIG) {
hash_location = ptr;
goto done_opts;
}
}
ptr += opsize - 2;
length -= opsize;
}
done_opts:
/* do we have a hash as expected? */
if (!hash_expected) {
if (!hash_location)