diff options
| -rw-r--r-- | net/ipv4/tcp_input.c | 135 |
1 files changed, 67 insertions, 68 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 18e099c6fa62..fa2c85ca5bc3 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3278,81 +3278,80 @@ void tcp_parse_options(struct sk_buff *skb, struct tcp_options_received *opt_rx, int opsize; switch (opcode) { - case TCPOPT_EOL: + case TCPOPT_EOL: + return; + case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */ + length--; + continue; + default: + opsize = *ptr++; + if (opsize < 2) /* "silly options" */ return; - case TCPOPT_NOP: /* Ref: RFC 793 section 3.1 */ - length--; - continue; - default: - opsize=*ptr++; - if (opsize < 2) /* "silly options" */ - return; - if (opsize > length) - return; /* don't parse partial options */ - switch (opcode) { - case TCPOPT_MSS: - if (opsize==TCPOLEN_MSS && th->syn && !estab) { - u16 in_mss = ntohs(get_unaligned((__be16 *)ptr)); - if (in_mss) { - if (opt_rx->user_mss && opt_rx->user_mss < in_mss) - in_mss = opt_rx->user_mss; - opt_rx->mss_clamp = in_mss; - } - } - break; - case TCPOPT_WINDOW: - if (opsize==TCPOLEN_WINDOW && th->syn && !estab) - if (sysctl_tcp_window_scaling) { - __u8 snd_wscale = *(__u8 *) ptr; - opt_rx->wscale_ok = 1; - if (snd_wscale > 14) { - if (net_ratelimit()) - printk(KERN_INFO "tcp_parse_options: Illegal window " - "scaling value %d >14 received.\n", - snd_wscale); - snd_wscale = 14; - } - opt_rx->snd_wscale = snd_wscale; - } - break; - case TCPOPT_TIMESTAMP: - if (opsize==TCPOLEN_TIMESTAMP) { - if ((estab && opt_rx->tstamp_ok) || - (!estab && sysctl_tcp_timestamps)) { - opt_rx->saw_tstamp = 1; - opt_rx->rcv_tsval = ntohl(get_unaligned((__be32 *)ptr)); - opt_rx->rcv_tsecr = ntohl(get_unaligned((__be32 *)(ptr+4))); - } + if (opsize > length) + return; /* don't parse partial options */ + switch (opcode) { + case TCPOPT_MSS: + if (opsize == TCPOLEN_MSS && th->syn && !estab) { + u16 in_mss = ntohs(get_unaligned((__be16 *)ptr)); + if (in_mss) { + if (opt_rx->user_mss && + opt_rx->user_mss < in_mss) + in_mss = opt_rx->user_mss; + opt_rx->mss_clamp = in_mss; } - break; - case TCPOPT_SACK_PERM: - if (opsize==TCPOLEN_SACK_PERM && th->syn && !estab) { - if (sysctl_tcp_sack) { - opt_rx->sack_ok = 1; - tcp_sack_reset(opt_rx); - } + } + break; + case TCPOPT_WINDOW: + if (opsize == TCPOLEN_WINDOW && th->syn && + !estab && sysctl_tcp_window_scaling) { + __u8 snd_wscale = *(__u8 *)ptr; + opt_rx->wscale_ok = 1; + if (snd_wscale > 14) { + if (net_ratelimit()) + printk(KERN_INFO "tcp_parse_options: Illegal window " + "scaling value %d >14 received.\n", + snd_wscale); + snd_wscale = 14; } - break; + opt_rx->snd_wscale = snd_wscale; + } + break; + case TCPOPT_TIMESTAMP: + if ((opsize == TCPOLEN_TIMESTAMP) && + ((estab && opt_rx->tstamp_ok) || + (!estab && sysctl_tcp_timestamps))) { + opt_rx->saw_tstamp = 1; + opt_rx->rcv_tsval = ntohl(get_unaligned((__be32 *)ptr)); + opt_rx->rcv_tsecr = ntohl(get_unaligned((__be32 *)(ptr+4))); + } + break; + case TCPOPT_SACK_PERM: + if (opsize == TCPOLEN_SACK_PERM && th->syn && + !estab && sysctl_tcp_sack) { + opt_rx->sack_ok = 1; + tcp_sack_reset(opt_rx); + } + break; - case TCPOPT_SACK: - if ((opsize >= (TCPOLEN_SACK_BASE + TCPOLEN_SACK_PERBLOCK)) && - !((opsize - TCPOLEN_SACK_BASE) % TCPOLEN_SACK_PERBLOCK) && - opt_rx->sack_ok) { - TCP_SKB_CB(skb)->sacked = (ptr - 2) - (unsigned char *)th; - } - break; + case TCPOPT_SACK: + if ((opsize >= (TCPOLEN_SACK_BASE + TCPOLEN_SACK_PERBLOCK)) && + !((opsize - TCPOLEN_SACK_BASE) % TCPOLEN_SACK_PERBLOCK) && + opt_rx->sack_ok) { + TCP_SKB_CB(skb)->sacked = (ptr - 2) - (unsigned char *)th; + } + break; #ifdef CONFIG_TCP_MD5SIG - case TCPOPT_MD5SIG: - /* - * The MD5 Hash has already been - * checked (see tcp_v{4,6}_do_rcv()). - */ - break; + case TCPOPT_MD5SIG: + /* + * The MD5 Hash has already been + * checked (see tcp_v{4,6}_do_rcv()). + */ + break; #endif - } + } - ptr+=opsize-2; - length-=opsize; + ptr += opsize-2; + length -= opsize; } } } |