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ipv6: improve ipv6_find_hdr() to skip empty routing headers

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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 <aatteka@nicira.com>
Signed-off-by: Jesse Gross <jesse@nicira.com>
This commit is contained in:
Ansis Atteka 2012-11-09 17:11:31 -08:00 committed by Jesse Gross
parent f8f626754e
commit 9195bb8e38
2 changed files with 31 additions and 10 deletions
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5
include/net/ipv6.h
View File

@ -631,8 +631,9 @@ extern int ipv6_skip_exthdr(const struct sk_buff *, int start,
extern bool ipv6_ext_hdr(u8 nexthdr);
enum {
IP6_FH_F_FRAG = (1 << 0),
IP6_FH_F_AUTH = (1 << 1),
IP6_FH_F_FRAG = (1 << 0),
IP6_FH_F_AUTH = (1 << 1),
IP6_FH_F_SKIP_RH = (1 << 2),
};
/* find specified header and get offset to it */

36
net/ipv6/exthdrs_core.c
View File

@ -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;