/* * netsniff-ng - the packet sniffing beast * Copyright 2012 Markus Amend , Deutsche Flugsicherung GmbH * Subject to the GPL, version 2. * * http://tools.ietf.org/html/rfc3032 */ #include #include #include /* for ntohs() */ #include #include "proto.h" #include "protos.h" #include "dissector_eth.h" #include "built_in.h" #include "pkt_buff.h" struct mpls_uchdr { uint32_t mpls_uc_hdr; } __packed; static int mpls_uc_next_proto(struct pkt_buff *pkt) { uint8_t proto; uint16_t key = 0; if (pkt_len(pkt)) proto = *(pkt->data); else return -EIO; /* FIXME: Right now only test for IP Version field */ switch (proto >> 4) { case 4: key = 0x0800; /* IPv4*/ break; case 6: key = 0x86DD; /* IPv6*/ break; default: /* Nothing detected ... */ return -ENOENT; } return key; } static void mpls_uc_full(struct pkt_buff *pkt) { int next; uint32_t mpls_uc_data; struct mpls_uchdr *mpls_uc; uint8_t s = 0; do { mpls_uc = (struct mpls_uchdr *) pkt_pull(pkt, sizeof(*mpls_uc)); if (mpls_uc == NULL) return; mpls_uc_data = ntohl(mpls_uc->mpls_uc_hdr); s = (mpls_uc_data >> 8) & 0x1; tprintf(" [ MPLS "); tprintf("Label (%u), ", mpls_uc_data >> 12); tprintf("Exp (%u), ", (mpls_uc_data >> 9) & 0x7); tprintf("S (%u), ", s); tprintf("TTL (%u)", (mpls_uc_data & 0xFF)); tprintf(" ]\n"); } while (!s); next = mpls_uc_next_proto(pkt); if (next < 0) return; pkt_set_proto(pkt, ð_lay2, (uint16_t) next); } static void mpls_uc_less(struct pkt_buff *pkt) { int next; uint32_t mpls_uc_data; struct mpls_uchdr *mpls_uc; uint8_t s = 0; do { mpls_uc = (struct mpls_uchdr *) pkt_pull(pkt, sizeof(*mpls_uc)); if (mpls_uc == NULL) return; mpls_uc_data = ntohl(mpls_uc->mpls_uc_hdr); s = (mpls_uc_data >> 8) & 0x1; tprintf(" MPLS/%u", mpls_uc_data >> 12); } while (!s); next = mpls_uc_next_proto(pkt); if (next < 0) return; pkt_set_proto(pkt, ð_lay2, (uint16_t) next); } struct protocol mpls_uc_ops = { .key = 0x8847, .print_full = mpls_uc_full, .print_less = mpls_uc_less, }; 77b5edec4d2b62560b5245199af04846476c'>diff
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authorLiping Zhang <liping.zhang@spreadtrum.com>2016-09-17 14:31:20 +0800
committerPablo Neira Ayuso <pablo@netfilter.org>2016-09-23 09:30:26 +0200
commita20877b5edec4d2b62560b5245199af04846476c (patch)
treeda43d9f571eb5a6c41b013645c831564e2f7b534
parent8dc3c2b86bb16e8f345b80a8af69696e9a7edb65 (diff)
netfilter: nf_tables: check tprot_set first when we use xt.thoff
pkt->xt.thoff is not always set properly, but we use it without any check. For payload expr, it will cause wrong results. For nftrace, we may notify the wrong network or transport header to the user space, furthermore, input the following nft rules, warning message will be printed out: # nft add rule arp filter output meta nftrace set 1 WARNING: CPU: 0 PID: 13428 at net/netfilter/nf_tables_trace.c:263 nft_trace_notify+0x4a3/0x5e0 [nf_tables] Call Trace: [<ffffffff813d58ae>] dump_stack+0x63/0x85 [<ffffffff810a4c0b>] __warn+0xcb/0xf0 [<ffffffff810a4d3d>] warn_slowpath_null+0x1d/0x20 [<ffffffffa0589703>] nft_trace_notify+0x4a3/0x5e0 [nf_tables] [ ... ] [<ffffffffa05690a8>] nft_do_chain_arp+0x78/0x90 [nf_tables_arp] [<ffffffff816f4aa2>] nf_iterate+0x62/0x80 [<ffffffff816f4b33>] nf_hook_slow+0x73/0xd0 [<ffffffff81732bbf>] arp_xmit+0x8f/0xb0 [ ... ] [<ffffffff81732d36>] arp_solicit+0x106/0x2c0 So before we use pkt->xt.thoff, check the tprot_set first. Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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