From 9195bb8e381d81d5a315f911904cdf0cfcc919b8 Mon Sep 17 00:00:00 2001 From: Ansis Atteka Date: Fri, 9 Nov 2012 17:11:31 -0800 Subject: ipv6: improve ipv6_find_hdr() to skip empty routing headers This patch prepares ipv6_find_hdr() function so that it could be able to skip routing headers, where segements_left is 0. This is required to handle multiple routing header case correctly when changing IPv6 addresses. Signed-off-by: Ansis Atteka Signed-off-by: Jesse Gross --- net/ipv6/exthdrs_core.c | 36 ++++++++++++++++++++++++++++-------- 1 file changed, 28 insertions(+), 8 deletions(-) (limited to 'net/ipv6/exthdrs_core.c') diff --git a/net/ipv6/exthdrs_core.c b/net/ipv6/exthdrs_core.c index 8ea253ad35b1..11b4e29c8452 100644 --- a/net/ipv6/exthdrs_core.c +++ b/net/ipv6/exthdrs_core.c @@ -132,9 +132,11 @@ EXPORT_SYMBOL(ipv6_skip_exthdr); * *offset is meaningless and fragment offset is stored in *fragoff if fragoff * isn't NULL. * - * if flags is not NULL and it's a fragment, then the frag flag IP6_FH_F_FRAG - * will be set. If it's an AH header, the IP6_FH_F_AUTH flag is set and - * target < 0, then this function will stop at the AH header. + * if flags is not NULL and it's a fragment, then the frag flag + * IP6_FH_F_FRAG will be set. If it's an AH header, the + * IP6_FH_F_AUTH flag is set and target < 0, then this function will + * stop at the AH header. If IP6_FH_F_SKIP_RH flag was passed, then this + * function will skip all those routing headers, where segements_left was 0. */ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, int target, unsigned short *fragoff, int *flags) @@ -142,6 +144,7 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, unsigned int start = skb_network_offset(skb) + sizeof(struct ipv6hdr); u8 nexthdr = ipv6_hdr(skb)->nexthdr; unsigned int len; + bool found; if (fragoff) *fragoff = 0; @@ -159,9 +162,10 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, } len = skb->len - start; - while (nexthdr != target) { + do { struct ipv6_opt_hdr _hdr, *hp; unsigned int hdrlen; + found = (nexthdr == target); if ((!ipv6_ext_hdr(nexthdr)) || nexthdr == NEXTHDR_NONE) { if (target < 0) @@ -172,6 +176,20 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr); if (hp == NULL) return -EBADMSG; + + if (nexthdr == NEXTHDR_ROUTING) { + struct ipv6_rt_hdr _rh, *rh; + + rh = skb_header_pointer(skb, start, sizeof(_rh), + &_rh); + if (rh == NULL) + return -EBADMSG; + + if (flags && (*flags & IP6_FH_F_SKIP_RH) && + rh->segments_left == 0) + found = false; + } + if (nexthdr == NEXTHDR_FRAGMENT) { unsigned short _frag_off; __be16 *fp; @@ -205,10 +223,12 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, } else hdrlen = ipv6_optlen(hp); - nexthdr = hp->nexthdr; - len -= hdrlen; - start += hdrlen; - } + if (!found) { + nexthdr = hp->nexthdr; + len -= hdrlen; + start += hdrlen; + } + } while (!found); *offset = start; return nexthdr; -- cgit v1.2.3-59-g8ed1b