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Commit 7d5d5525 authored by YOSHIFUJI Hideaki's avatar YOSHIFUJI Hideaki
Browse files

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



Signed-off-by: default avatarYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
parent 81b302a3

include/net/tcp.h

+2 −0
Original line number Diff line number Diff line
@@ -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

 */

net/ipv4/tcp_input.c

+40 −0
Original line number Diff line number Diff line
@@ -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);

net/ipv4/tcp_ipv4.c

+1 −41
Original line number Diff line number Diff line
@@ -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;

net/ipv6/tcp_ipv6.c

+1 −32
Original line number Diff line number Diff line
@@ -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)