--- embedaddon/dnsmasq/src/dump.c 2021/03/17 00:56:46 1.1 +++ embedaddon/dnsmasq/src/dump.c 2023/09/27 11:02:07 1.1.1.2 @@ -1,4 +1,4 @@ -/* dnsmasq is Copyright (c) 2000-2021 Simon Kelley +/* dnsmasq is Copyright (c) 2000-2022 Simon Kelley This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -18,7 +18,11 @@ #ifdef HAVE_DUMPFILE +#include + static u32 packet_count; +static void do_dump_packet(int mask, void *packet, size_t len, + union mysockaddr *src, union mysockaddr *dst, int port, int proto); /* https://wiki.wireshark.org/Development/LibpcapFileFormat */ struct pcap_hdr_s { @@ -79,8 +83,46 @@ void dump_init(void) } } -void dump_packet(int mask, void *packet, size_t len, union mysockaddr *src, union mysockaddr *dst) +void dump_packet_udp(int mask, void *packet, size_t len, + union mysockaddr *src, union mysockaddr *dst, int fd) { + union mysockaddr fd_addr; + socklen_t addr_len = sizeof(fd_addr); + + if (daemon->dumpfd != -1 && (mask & daemon->dump_mask)) + { + /* if fd is negative it carries a port number (negated) + which we use as a source or destination when not otherwise + specified so wireshark can ID the packet. + If both src and dst are specified, set this to -1 to avoid + a spurious getsockname() call. */ + int port = (fd < 0) ? -fd : -1; + + /* fd >= 0 is a file descriptor and the address of that file descriptor is used + in place of a NULL src or dst. */ + if (fd >= 0 && getsockname(fd, (struct sockaddr *)&fd_addr, &addr_len) != -1) + { + if (!src) + src = &fd_addr; + + if (!dst) + dst = &fd_addr; + } + + do_dump_packet(mask, packet, len, src, dst, port, IPPROTO_UDP); + } +} + +void dump_packet_icmp(int mask, void *packet, size_t len, + union mysockaddr *src, union mysockaddr *dst) +{ + if (daemon->dumpfd != -1 && (mask & daemon->dump_mask)) + do_dump_packet(mask, packet, len, src, dst, -1, IPPROTO_ICMP); +} + +static void do_dump_packet(int mask, void *packet, size_t len, + union mysockaddr *src, union mysockaddr *dst, int port, int proto) +{ struct ip ip; struct ip6_hdr ip6; int family; @@ -96,13 +138,14 @@ void dump_packet(int mask, void *packet, size_t len, u void *iphdr; size_t ipsz; int rc; + + /* if port != -1 it carries a port number + which we use as a source or destination when not otherwise + specified so wireshark can ID the packet. + If both src and dst are specified, set this to -1 to avoid + a spurious getsockname() call. */ + udp.uh_sport = udp.uh_dport = htons(port < 0 ? 0 : port); - if (daemon->dumpfd == -1 || !(mask & daemon->dump_mask)) - return; - - /* So wireshark can Id the packet. */ - udp.uh_sport = udp.uh_dport = htons(NAMESERVER_PORT); - if (src) family = src->sa.sa_family; else @@ -115,10 +158,16 @@ void dump_packet(int mask, void *packet, size_t len, u memset(&ip6, 0, sizeof(ip6)); ip6.ip6_vfc = 6 << 4; - ip6.ip6_plen = htons(sizeof(struct udphdr) + len); - ip6.ip6_nxt = IPPROTO_UDP; ip6.ip6_hops = 64; + if ((ip6.ip6_nxt = proto) == IPPROTO_UDP) + ip6.ip6_plen = htons(sizeof(struct udphdr) + len); + else + { + proto = ip6.ip6_nxt = IPPROTO_ICMPV6; + ip6.ip6_plen = htons(len); + } + if (src) { memcpy(&ip6.ip6_src, &src->in6.sin6_addr, IN6ADDRSZ); @@ -134,9 +183,8 @@ void dump_packet(int mask, void *packet, size_t len, u /* start UDP checksum */ for (sum = 0, i = 0; i < IN6ADDRSZ; i+=2) { - sum += ip6.ip6_src.s6_addr[i] + (ip6.ip6_src.s6_addr[i+1] << 8) ; - sum += ip6.ip6_dst.s6_addr[i] + (ip6.ip6_dst.s6_addr[i+1] << 8) ; - + sum += ntohs((ip6.ip6_src.s6_addr[i] << 8) + (ip6.ip6_src.s6_addr[i+1])) ; + sum += ntohs((ip6.ip6_dst.s6_addr[i] << 8) + (ip6.ip6_dst.s6_addr[i+1])) ; } } else @@ -147,9 +195,15 @@ void dump_packet(int mask, void *packet, size_t len, u ip.ip_v = IPVERSION; ip.ip_hl = sizeof(struct ip) / 4; - ip.ip_len = htons(sizeof(struct ip) + sizeof(struct udphdr) + len); ip.ip_ttl = IPDEFTTL; - ip.ip_p = IPPROTO_UDP; + + if ((ip.ip_p = proto) == IPPROTO_UDP) + ip.ip_len = htons(sizeof(struct ip) + sizeof(struct udphdr) + len); + else + { + ip.ip_len = htons(sizeof(struct ip) + len); + proto = ip.ip_p = IPPROTO_ICMP; + } if (src) { @@ -170,7 +224,7 @@ void dump_packet(int mask, void *packet, size_t len, u sum = (sum & 0xffff) + (sum >> 16); ip.ip_sum = (sum == 0xffff) ? sum : ~sum; - /* start UDP checksum */ + /* start UDP/ICMP checksum */ sum = ip.ip_src.s_addr & 0xffff; sum += (ip.ip_src.s_addr >> 16) & 0xffff; sum += ip.ip_dst.s_addr & 0xffff; @@ -180,31 +234,61 @@ void dump_packet(int mask, void *packet, size_t len, u if (len & 1) ((unsigned char *)packet)[len] = 0; /* for checksum, in case length is odd. */ - udp.uh_sum = 0; - udp.uh_ulen = htons(sizeof(struct udphdr) + len); - sum += htons(IPPROTO_UDP); - sum += htons(sizeof(struct udphdr) + len); - for (i = 0; i < sizeof(struct udphdr)/2; i++) - sum += ((u16 *)&udp)[i]; - for (i = 0; i < (len + 1) / 2; i++) - sum += ((u16 *)packet)[i]; - while (sum >> 16) - sum = (sum & 0xffff) + (sum >> 16); - udp.uh_sum = (sum == 0xffff) ? sum : ~sum; + if (proto == IPPROTO_UDP) + { + /* Add Remaining part of the pseudoheader. Note that though the + IPv6 pseudoheader is very different to the IPv4 one, the + net result of this calculation is correct as long as the + packet length is less than 65536, which is fine for us. */ + sum += htons(IPPROTO_UDP); + sum += htons(sizeof(struct udphdr) + len); + + udp.uh_sum = 0; + udp.uh_ulen = htons(sizeof(struct udphdr) + len); + + for (i = 0; i < sizeof(struct udphdr)/2; i++) + sum += ((u16 *)&udp)[i]; + for (i = 0; i < (len + 1) / 2; i++) + sum += ((u16 *)packet)[i]; + while (sum >> 16) + sum = (sum & 0xffff) + (sum >> 16); + udp.uh_sum = (sum == 0xffff) ? sum : ~sum; + pcap_header.incl_len = pcap_header.orig_len = ipsz + sizeof(udp) + len; + } + else + { + /* ICMP - ICMPv6 packet is a superset of ICMP */ + struct icmp6_hdr *icmp = packet; + + /* See comment in UDP code above. */ + sum += htons(proto); + sum += htons(len); + + icmp->icmp6_cksum = 0; + for (i = 0; i < (len + 1) / 2; i++) + sum += ((u16 *)packet)[i]; + while (sum >> 16) + sum = (sum & 0xffff) + (sum >> 16); + icmp->icmp6_cksum = (sum == 0xffff) ? sum : ~sum; + + pcap_header.incl_len = pcap_header.orig_len = ipsz + len; + } + rc = gettimeofday(&time, NULL); pcap_header.ts_sec = time.tv_sec; pcap_header.ts_usec = time.tv_usec; - pcap_header.incl_len = pcap_header.orig_len = ipsz + sizeof(udp) + len; if (rc == -1 || !read_write(daemon->dumpfd, (void *)&pcap_header, sizeof(pcap_header), 0) || !read_write(daemon->dumpfd, iphdr, ipsz, 0) || - !read_write(daemon->dumpfd, (void *)&udp, sizeof(udp), 0) || + (proto == IPPROTO_UDP && !read_write(daemon->dumpfd, (void *)&udp, sizeof(udp), 0)) || !read_write(daemon->dumpfd, (void *)packet, len, 0)) my_syslog(LOG_ERR, _("failed to write packet dump")); + else if (option_bool(OPT_EXTRALOG)) + my_syslog(LOG_INFO, _("%u dumping packet %u mask 0x%04x"), daemon->log_display_id, ++packet_count, mask); else - my_syslog(LOG_INFO, _("dumping UDP packet %u mask 0x%04x"), ++packet_count, mask); + my_syslog(LOG_INFO, _("dumping packet %u mask 0x%04x"), ++packet_count, mask); }