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Release 4.8 net/ipv6/exthdrs_core.c

Directory: net/ipv6
 * IPv6 library code, needed by static components when full IPv6 support is
 * not configured or static.
#include <linux/export.h>
#include <net/ipv6.h>

 * find out if nexthdr is a well-known extension header or a protocol

bool ipv6_ext_hdr(u8 nexthdr) { /* * find out if nexthdr is an extension header or a protocol */ return (nexthdr == NEXTHDR_HOP) || (nexthdr == NEXTHDR_ROUTING) || (nexthdr == NEXTHDR_FRAGMENT) || (nexthdr == NEXTHDR_AUTH) || (nexthdr == NEXTHDR_NONE) || (nexthdr == NEXTHDR_DEST); }


james morrisjames morris4495.65%133.33%
eric dumazeteric dumazet12.17%133.33%
hideaki yoshifujihideaki yoshifuji12.17%133.33%

EXPORT_SYMBOL(ipv6_ext_hdr); /* * Skip any extension headers. This is used by the ICMP module. * * Note that strictly speaking this conflicts with RFC 2460 4.0: * ...The contents and semantics of each extension header determine whether * or not to proceed to the next header. Therefore, extension headers must * be processed strictly in the order they appear in the packet; a * receiver must not, for example, scan through a packet looking for a * particular kind of extension header and process that header prior to * processing all preceding ones. * * We do exactly this. This is a protocol bug. We can't decide after a * seeing an unknown discard-with-error flavour TLV option if it's a * ICMP error message or not (errors should never be send in reply to * ICMP error messages). * * But I see no other way to do this. This might need to be reexamined * when Linux implements ESP (and maybe AUTH) headers. * --AK * * This function parses (probably truncated) exthdr set "hdr". * "nexthdrp" initially points to some place, * where type of the first header can be found. * * It skips all well-known exthdrs, and returns pointer to the start * of unparsable area i.e. the first header with unknown type. * If it is not NULL *nexthdr is updated by type/protocol of this header. * * NOTES: - if packet terminated with NEXTHDR_NONE it returns NULL. * - it may return pointer pointing beyond end of packet, * if the last recognized header is truncated in the middle. * - if packet is truncated, so that all parsed headers are skipped, * it returns NULL. * - First fragment header is skipped, not-first ones * are considered as unparsable. * - Reports the offset field of the final fragment header so it is * possible to tell whether this is a first fragment, later fragment, * or not fragmented. * - ESP is unparsable for now and considered like * normal payload protocol. * - Note also special handling of AUTH header. Thanks to IPsec wizards. * * --ANK (980726) */
int ipv6_skip_exthdr(const struct sk_buff *skb, int start, u8 *nexthdrp, __be16 *frag_offp) { u8 nexthdr = *nexthdrp; *frag_offp = 0; while (ipv6_ext_hdr(nexthdr)) { struct ipv6_opt_hdr _hdr, *hp; int hdrlen; if (nexthdr == NEXTHDR_NONE) return -1; hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr); if (!hp) return -1; if (nexthdr == NEXTHDR_FRAGMENT) { __be16 _frag_off, *fp; fp = skb_header_pointer(skb, start+offsetof(struct frag_hdr, frag_off), sizeof(_frag_off), &_frag_off); if (!fp) return -1; *frag_offp = *fp; if (ntohs(*frag_offp) & ~0x7) break; hdrlen = 8; } else if (nexthdr == NEXTHDR_AUTH) hdrlen = (hp->hdrlen+2)<<2; else hdrlen = ipv6_optlen(hp); nexthdr = hp->nexthdr; start += hdrlen; } *nexthdrp = nexthdr; return start; }


james morrisjames morris14470.94%116.67%
david s. millerdavid s. miller3617.73%116.67%
jesse grossjesse gross167.88%116.67%
herbert xuherbert xu41.97%116.67%
ian morrisian morris20.99%116.67%
al viroal viro10.49%116.67%

int ipv6_find_tlv(const struct sk_buff *skb, int offset, int type) { const unsigned char *nh = skb_network_header(skb); int packet_len = skb_tail_pointer(skb) - skb_network_header(skb); struct ipv6_opt_hdr *hdr; int len; if (offset + 2 > packet_len) goto bad; hdr = (struct ipv6_opt_hdr *)(nh + offset); len = ((hdr->hdrlen + 1) << 3); if (offset + len > packet_len) goto bad; offset += 2; len -= 2; while (len > 0) { int opttype = nh[offset]; int optlen; if (opttype == type) return offset; switch (opttype) { case IPV6_TLV_PAD1: optlen = 1; break; default: optlen = nh[offset + 1] + 2; if (optlen > len) goto bad; break; } offset += optlen; len -= optlen; } /* not_found */ bad: return -1; }


vlad yasevichvlad yasevich17896.22%133.33%
simon hormansimon horman63.24%133.33%
huw davieshuw davies10.54%133.33%

EXPORT_SYMBOL_GPL(ipv6_find_tlv); /* * find the offset to specified header or the protocol number of last header * if target < 0. "last header" is transport protocol header, ESP, or * "No next header". * * Note that *offset is used as input/output parameter. an if it is not zero, * then it must be a valid offset to an inner IPv6 header. This can be used * to explore inner IPv6 header, eg. ICMPv6 error messages. * * If target header is found, its offset is set in *offset and return protocol * number. Otherwise, return -1. * * If the first fragment doesn't contain the final protocol header or * NEXTHDR_NONE it is considered invalid. * * Note that non-1st fragment is special case that "the protocol number * of last header" is "next header" field in Fragment header. In this case, * *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 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) { 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; if (*offset) { struct ipv6hdr _ip6, *ip6; ip6 = skb_header_pointer(skb, *offset, sizeof(_ip6), &_ip6); if (!ip6 || (ip6->version != 6)) { printk(KERN_ERR "IPv6 header not found\n"); return -EBADMSG; } start = *offset + sizeof(struct ipv6hdr); nexthdr = ip6->nexthdr; } len = skb->len - start; do { struct ipv6_opt_hdr _hdr, *hp; unsigned int hdrlen; found = (nexthdr == target); if ((!ipv6_ext_hdr(nexthdr)) || nexthdr == NEXTHDR_NONE) { if (target < 0 || found) break; return -ENOENT; } hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr); if (!hp) return -EBADMSG; if (nexthdr == NEXTHDR_ROUTING) { struct ipv6_rt_hdr _rh, *rh; rh = skb_header_pointer(skb, start, sizeof(_rh), &_rh); if (!rh) 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; if (flags) /* Indicate that this is a fragment */ *flags |= IP6_FH_F_FRAG; fp = skb_header_pointer(skb, start+offsetof(struct frag_hdr, frag_off), sizeof(_frag_off), &_frag_off); if (!fp) return -EBADMSG; _frag_off = ntohs(*fp) & ~0x7; if (_frag_off) { if (target < 0 && ((!ipv6_ext_hdr(hp->nexthdr)) || hp->nexthdr == NEXTHDR_NONE)) { if (fragoff) *fragoff = _frag_off; return hp->nexthdr; } if (!found) return -ENOENT; if (fragoff) *fragoff = _frag_off; break; } hdrlen = 8; } else if (nexthdr == NEXTHDR_AUTH) { if (flags && (*flags & IP6_FH_F_AUTH) && (target < 0)) break; hdrlen = (hp->hdrlen + 2) << 2; } else hdrlen = ipv6_optlen(hp); if (!found) { nexthdr = hp->nexthdr; len -= hdrlen; start += hdrlen; } } while (!found); *offset = start; return nexthdr; }


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ansis attekaansis atteka8616.80%120.00%
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ian morrisian morris30.59%120.00%
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Directory: net/ipv6
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