gfwleak/common-tools-tcpdump-mesa
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🐞 fix(print_packt and dump_packet): 读包模式下开启-g，对v4和v6头同时进行bpf

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This commit is contained in:
yangwei
2021-09-24 14:23:54 +08:00
parent ca549c5d44
commit 453d331717
1 changed files with 53 additions and 57 deletions
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110
src/tcpdump.c
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@@ -3077,48 +3077,44 @@ dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
static void
MESA_dump_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *raw_pkt)
{
//char modify_pkt_buf[2048];
int inner_pkt_len;
int ipv4_inner_pkt_len;
int ipv6_inner_pkt_len;
int bpf_match_ipv4 = 0, bpf_match_ipv6 = 0;
++packets_captured;
++infodelay;
//memcpy(modify_pkt_buf, raw_pkt, h->caplen >= 2048? 2048:h->caplen);
//inner_pkt_len = MESA_dump_seek_to_inner(modify_pkt_buf, h->caplen);
//if(inner_pkt_len < 0){
// return;
//}
struct mesa_ip4_hdr *ip4hdr_greedy;
struct mesa_ip6_hdr *ip6hdr_greedy;
const unsigned char *inner_iphdr = NULL;
const unsigned char *ipv4_inner_iphdr = NULL;
const unsigned char *ipv6_inner_iphdr = NULL;
ip4hdr_greedy = (struct mesa_ip4_hdr *)MESA_jump_layer_greedy(raw_pkt, ADDR_TYPE_MAC, __ADDR_TYPE_IP_PAIR_V4);
if(ip4hdr_greedy)
{
inner_iphdr = (const unsigned char *)ip4hdr_greedy;
inner_pkt_len = h->caplen - ((const u_char *)ip4hdr_greedy - raw_pkt) ;
ipv4_inner_iphdr = (const unsigned char *)ip4hdr_greedy;
ipv4_inner_pkt_len = h->caplen - ((const u_char *)ip4hdr_greedy - raw_pkt) ;
}
else
{
ip6hdr_greedy = (struct mesa_ip6_hdr *)MESA_jump_layer_greedy(raw_pkt, ADDR_TYPE_MAC, __ADDR_TYPE_IP_PAIR_V6);
if(ip6hdr_greedy)
{
inner_iphdr = (const unsigned char *)ip6hdr_greedy;
inner_pkt_len = h->caplen - ((const u_char *)ip6hdr_greedy - raw_pkt);
}
else
{
return;
}
}
ip6hdr_greedy = (struct mesa_ip6_hdr *)MESA_jump_layer_greedy(raw_pkt, ADDR_TYPE_MAC, __ADDR_TYPE_IP_PAIR_V6);
if(ip6hdr_greedy)
{
ipv6_inner_iphdr = (const unsigned char *)ip6hdr_greedy;
ipv6_inner_pkt_len = h->caplen - ((const u_char *)ip6hdr_greedy - raw_pkt);
}
if(has_bpf_filter_flag != 0){
if(0 == bpf_filter(fcode.bf_insns,
(const unsigned char *)inner_iphdr, inner_pkt_len, inner_pkt_len)){
return;
}
}
if (has_bpf_filter_flag != 0)
{
if (ip4hdr_greedy)
{
bpf_match_ipv4 = bpf_filter(fcode.bf_insns, (const unsigned char *)ipv4_inner_iphdr, ipv4_inner_pkt_len, ipv4_inner_pkt_len);
}
if (ip6hdr_greedy)
{
bpf_match_ipv6 = bpf_filter(fcode.bf_insns, (const unsigned char *)ipv6_inner_iphdr, ipv6_inner_pkt_len, ipv6_inner_pkt_len);
}
if (bpf_match_ipv4 == 0 && bpf_match_ipv6 == 0)
return;
}
/* -w参数要存储包, 实际存储的包还是用原始报文, 只是BPF用内层过滤 */
pcap_dump(user, h, raw_pkt);
@@ -3163,8 +3159,6 @@ print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *sp)
static void
MESA_dump_print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *pkt)
{
int inner_pkt_len;
#if 0
/* 此函数仅用于tcpdump屏幕打印, 直接修改pkt原始包, 避免再copy一次, 节约点CPU */
inner_pkt_len = MESA_dump_seek_to_inner(pkt, h->caplen);
@@ -3183,38 +3177,40 @@ MESA_dump_print_packet(u_char *user, const struct pcap_pkthdr *h, const u_char *
((struct pcap_pkthdr *)h)->caplen = (unsigned int)inner_pkt_len;
((struct pcap_pkthdr *)h)->len = (unsigned int)inner_pkt_len;
#else
int ipv4_inner_pkt_len;
int ipv6_inner_pkt_len;
int bpf_match_ipv4 = 0, bpf_match_ipv6 = 0;
struct mesa_ip4_hdr *ip4hdr_greedy;
struct mesa_ip6_hdr *ip6hdr_greedy;
const unsigned char *inner_iphdr = NULL;
const unsigned char *ipv4_inner_iphdr = NULL;
const unsigned char *ipv6_inner_iphdr = NULL;
ip4hdr_greedy = (struct mesa_ip4_hdr *)MESA_jump_layer_greedy(pkt, ADDR_TYPE_MAC, __ADDR_TYPE_IP_PAIR_V4);
if(ip4hdr_greedy)
{
inner_iphdr = (const unsigned char *)ip4hdr_greedy;
inner_pkt_len = h->caplen - ((const unsigned char *)ip4hdr_greedy - pkt);
ipv4_inner_iphdr = (const unsigned char *)ip4hdr_greedy;
ipv4_inner_pkt_len = h->caplen - ((const unsigned char *)ip4hdr_greedy - pkt);
}
else
ip6hdr_greedy = (struct mesa_ip6_hdr *)MESA_jump_layer_greedy(pkt, ADDR_TYPE_MAC, __ADDR_TYPE_IP_PAIR_V6);
if (ip6hdr_greedy)
{
ip6hdr_greedy = (struct mesa_ip6_hdr *)MESA_jump_layer_greedy(pkt, ADDR_TYPE_MAC, __ADDR_TYPE_IP_PAIR_V6);
if(ip6hdr_greedy)
{
inner_iphdr = (const unsigned char *)ip6hdr_greedy;
inner_pkt_len = h->caplen - ((const unsigned char *)ip6hdr_greedy - pkt);
}
else
{
return;
}
ipv6_inner_iphdr = (const unsigned char *)ip6hdr_greedy;
ipv6_inner_pkt_len = h->caplen - ((const unsigned char *)ip6hdr_greedy - pkt);
}
if (has_bpf_filter_flag != 0)
{
if (0 == bpf_filter(fcode.bf_insns,
(const unsigned char *)inner_iphdr, inner_pkt_len, inner_pkt_len))
{
return;
}
}
if (has_bpf_filter_flag != 0)
{
if (ip4hdr_greedy)
{
bpf_match_ipv4 = bpf_filter(fcode.bf_insns, (const unsigned char *)ipv4_inner_iphdr, ipv4_inner_pkt_len, ipv4_inner_pkt_len);
}
if (ip6hdr_greedy)
{
bpf_match_ipv6 = bpf_filter(fcode.bf_insns, (const unsigned char *)ipv6_inner_iphdr, ipv6_inner_pkt_len, ipv6_inner_pkt_len);
}
if (bpf_match_ipv4 == 0 && bpf_match_ipv6 == 0)
return;
}
#endif
print_packet(user, h, pkt);