diff options
Diffstat (limited to 'ipv6.c')
-rw-r--r-- | ipv6.c | 52 |
1 files changed, 38 insertions, 14 deletions
@@ -77,6 +77,7 @@ void log_bad_address(const char *fmt, const struct in6_addr *src, const struct i int ipv6_packet(clat_packet out, int pos, const char *packet, size_t len) { const struct ip6_hdr *ip6 = (struct ip6_hdr *) packet; struct iphdr *ip_targ = (struct iphdr *) out[pos].iov_base; + struct ip6_frag *frag_hdr = NULL; uint8_t protocol; const char *next_header; size_t len_left; @@ -112,10 +113,6 @@ int ipv6_packet(clat_packet out, int pos, const char *packet, size_t len) { len_left = len - sizeof(struct ip6_hdr); protocol = ip6->ip6_nxt; - if (protocol == IPPROTO_ICMPV6) { - // ICMP and ICMPv6 have different protocol numbers. - protocol = IPPROTO_ICMP; - } /* Fill in the IPv4 header. We need to do this before we translate the packet because TCP and * UDP include parts of the IP header in the checksum. Set the length to zero because we don't @@ -124,21 +121,48 @@ int ipv6_packet(clat_packet out, int pos, const char *packet, size_t len) { fill_ip_header(ip_targ, 0, protocol, ip6); out[pos].iov_len = sizeof(struct iphdr); - // Calculate the pseudo-header checksum. + // If there's a Fragment header, parse it and decide what the next header is. + // Do this before calculating the pseudo-header checksum because it updates the next header value. + if (protocol == IPPROTO_FRAGMENT) { + frag_hdr = (struct ip6_frag *) next_header; + if (len_left < sizeof(*frag_hdr)) { + logmsg_dbg(ANDROID_LOG_ERROR, "ipv6_packet/too short for fragment header: %d", len); + return 0; + } + + next_header += sizeof(*frag_hdr); + len_left -= sizeof(*frag_hdr); + + protocol = parse_frag_header(frag_hdr, ip_targ); + } + + // ICMP and ICMPv6 have different protocol numbers. + if (protocol == IPPROTO_ICMPV6) { + protocol = IPPROTO_ICMP; + ip_targ->protocol = IPPROTO_ICMP; + } + + /* Calculate the pseudo-header checksum. + * Technically, the length that is used in the pseudo-header checksum is the transport layer + * length, which is not the same as len_left in the case of fragmented packets. But since + * translation does not change the transport layer length, the checksum is unaffected. + */ old_sum = ipv6_pseudo_header_checksum(ip6, len_left, protocol); new_sum = ipv4_pseudo_header_checksum(ip_targ, len_left); - // does not support IPv6 extension headers, this will drop any packet with them - if (protocol == IPPROTO_ICMP) { - iov_len = icmp6_packet(out, pos + 1, (const struct icmp6_hdr *) next_header, len_left); - } else if (ip6->ip6_nxt == IPPROTO_TCP) { - iov_len = tcp_packet(out, pos + 1, (const struct tcphdr *) next_header, old_sum, new_sum, + // Does not support IPv6 extension headers except Fragment. + if (frag_hdr && (frag_hdr->ip6f_offlg & IP6F_OFF_MASK)) { + iov_len = generic_packet(out, pos + 2, next_header, len_left); + } else if (protocol == IPPROTO_ICMP) { + iov_len = icmp6_packet(out, pos + 2, (const struct icmp6_hdr *) next_header, len_left); + } else if (protocol == IPPROTO_TCP) { + iov_len = tcp_packet(out, pos + 2, (const struct tcphdr *) next_header, old_sum, new_sum, len_left); - } else if (ip6->ip6_nxt == IPPROTO_UDP) { - iov_len = udp_packet(out, pos + 1, (const struct udphdr *) next_header, old_sum, new_sum, + } else if (protocol == IPPROTO_UDP) { + iov_len = udp_packet(out, pos + 2, (const struct udphdr *) next_header, old_sum, new_sum, len_left); - } else if (ip6->ip6_nxt == IPPROTO_GRE) { - iov_len = generic_packet(out, pos + 1, next_header, len_left); + } else if (protocol == IPPROTO_GRE) { + iov_len = generic_packet(out, pos + 2, next_header, len_left); } else { #if CLAT_DEBUG logmsg(ANDROID_LOG_ERROR, "ipv6_packet/unknown next header type: %x", ip6->ip6_nxt); |