/*
pong.c -- ICMP echo reply generator
- Copyright (C) 2013 Guus Sliepen <guus@tinc-vpn.org>
+ Copyright (C) 2013-2017 Guus Sliepen <guus@tinc-vpn.org>
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
#include "../src/system.h"
+#include "../src/ethernet.h"
+
uint8_t mymac[6] = {6, 5, 5, 6, 5, 5};
static ssize_t do_arp(uint8_t *buf, ssize_t len, struct sockaddr_in *in) {
struct ether_arp arp;
- memcpy(&arp, buf + 14, sizeof arp);
+ memcpy(&arp, buf + 14, sizeof(arp));
// Is it a valid ARP request?
- if(ntohs(arp.arp_hrd) != ARPHRD_ETHER || ntohs(arp.arp_pro) != ETH_P_IP || arp.arp_hln != ETH_ALEN || arp.arp_pln != sizeof in->sin_addr.s_addr || ntohs(arp.arp_op) != ARPOP_REQUEST)
+ if(ntohs(arp.arp_hrd) != ARPHRD_ETHER || ntohs(arp.arp_pro) != ETH_P_IP || arp.arp_hln != ETH_ALEN || arp.arp_pln != sizeof(in->sin_addr.s_addr) || ntohs(arp.arp_op) != ARPOP_REQUEST) {
return 0;
+ }
// Does it match our address?
- if(memcmp(&in->sin_addr.s_addr, arp.arp_tpa, 4))
+ if(memcmp(&in->sin_addr.s_addr, arp.arp_tpa, 4)) {
return 0;
+ }
// Swap addresses
memcpy(buf, buf + 6, 6);
memcpy(buf + 6, mymac, 6);
arp.arp_op = htons(ARPOP_REPLY);
- memcpy(arp.arp_tpa, arp.arp_spa, sizeof arp.arp_tpa);
- memcpy(arp.arp_tha, arp.arp_sha, sizeof arp.arp_tha);
- memcpy(arp.arp_spa, &in->sin_addr.s_addr, sizeof in->sin_addr.s_addr);
+ memcpy(arp.arp_tpa, arp.arp_spa, sizeof(arp.arp_tpa));
+ memcpy(arp.arp_tha, arp.arp_sha, sizeof(arp.arp_tha));
+ memcpy(arp.arp_spa, &in->sin_addr.s_addr, sizeof(in->sin_addr.s_addr));
memcpy(arp.arp_sha, mymac, 6);
- memcpy(buf + 14, &arp, sizeof arp);
+ memcpy(buf + 14, &arp, sizeof(arp));
return len;
}
struct icmp icmp;
// Does it match our address?
- if(memcmp(buf, mymac, 6))
+ if(memcmp(buf, mymac, 6)) {
return 0;
+ }
+
+ memcpy(&ip, buf + 14, sizeof(ip));
- memcpy(&ip, buf + 14, sizeof ip);
- if(memcmp(&ip.ip_dst, &in->sin_addr.s_addr, 4))
+ if(memcmp(&ip.ip_dst, &in->sin_addr.s_addr, 4)) {
return 0;
+ }
// Is it an ICMP echo request?
- if(ip.ip_p != IPPROTO_ICMP)
+ if(ip.ip_p != IPPROTO_ICMP) {
return 0;
+ }
+
+ memcpy(&icmp, buf + 14 + sizeof(ip), sizeof(icmp));
- memcpy(&icmp, buf + 14 + sizeof ip, sizeof icmp);
- if(icmp.icmp_type != ICMP_ECHO)
+ if(icmp.icmp_type != ICMP_ECHO) {
return 0;
+ }
// Return an echo reply
memcpy(buf, buf + 6, 6);
icmp.icmp_type = ICMP_ECHOREPLY;
- memcpy(buf + 14, &ip, sizeof ip);
- memcpy(buf + 14 + sizeof ip, &icmp, sizeof icmp);
+ memcpy(buf + 14, &ip, sizeof(ip));
+ memcpy(buf + 14 + sizeof(ip), &icmp, sizeof(icmp));
return len;
}
hints.ai_flags = AI_ADDRCONFIG;
errno = ENOENT;
+
if(getaddrinfo(argv[1], argv[2], &hints, &ai) || !ai) {
fprintf(stderr, "Could not resolve %s port %s: %s\n", argv[1], argv[2], strerror(errno));
return 1;
int fd;
fd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
+
if(!fd) {
fprintf(stderr, "Could not create socket: %s\n", strerror(errno));
return 1;
}
static const int one = 1;
- setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (void *)&one, sizeof one);
+ setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (void *)&one, sizeof(one));
if(bind(fd, ai->ai_addr, ai->ai_addrlen)) {
fprintf(stderr, "Could not bind socket: %s\n", strerror(errno));
}
switch(ai->ai_family) {
- case AF_INET: {
- struct ip_mreq mreq;
- struct sockaddr_in in;
- memcpy(&in, ai->ai_addr, sizeof in);
- mreq.imr_multiaddr.s_addr = in.sin_addr.s_addr;
- mreq.imr_interface.s_addr = htonl(INADDR_ANY);
- if(setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, (void *)&mreq, sizeof mreq)) {
- fprintf(stderr, "Cannot join multicast group: %s\n", strerror(errno));
- return 1;
- }
+ case AF_INET: {
+ struct ip_mreq mreq;
+ struct sockaddr_in in;
+ memcpy(&in, ai->ai_addr, sizeof(in));
+ mreq.imr_multiaddr.s_addr = in.sin_addr.s_addr;
+ mreq.imr_interface.s_addr = htonl(INADDR_ANY);
+
+ if(setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, (void *)&mreq, sizeof(mreq))) {
+ fprintf(stderr, "Cannot join multicast group: %s\n", strerror(errno));
+ return 1;
+ }
+
#ifdef IP_MULTICAST_LOOP
- setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, (const void *)&one, sizeof one);
+ setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, (const void *)&one, sizeof(one));
#endif
- } break;
+ }
+ break;
#ifdef IPV6_JOIN_GROUP
- case AF_INET6: {
- struct ipv6_mreq mreq;
- struct sockaddr_in6 in6;
- memcpy(&in6, ai->ai_addr, sizeof in6);
- memcpy(&mreq.ipv6mr_multiaddr, &in6.sin6_addr, sizeof mreq.ipv6mr_multiaddr);
- mreq.ipv6mr_interface = in6.sin6_scope_id;
- if(setsockopt(fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, (void *)&mreq, sizeof mreq)) {
- fprintf(stderr, "Cannot join multicast group: %s\n", strerror(errno));
- return 1;
- }
+
+ case AF_INET6: {
+ struct ipv6_mreq mreq;
+ struct sockaddr_in6 in6;
+ memcpy(&in6, ai->ai_addr, sizeof(in6));
+ memcpy(&mreq.ipv6mr_multiaddr, &in6.sin6_addr, sizeof(mreq.ipv6mr_multiaddr));
+ mreq.ipv6mr_interface = in6.sin6_scope_id;
+
+ if(setsockopt(fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, (void *)&mreq, sizeof(mreq))) {
+ fprintf(stderr, "Cannot join multicast group: %s\n", strerror(errno));
+ return 1;
+ }
+
#ifdef IPV6_MULTICAST_LOOP
- setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, (const void *)&one, sizeof one);
+ setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, (const void *)&one, sizeof(one));
#endif
- } break;
+ }
+ break;
#endif
- default:
- fprintf(stderr, "Multicast for address family %hx unsupported\n", ai->ai_family);
- return 1;
+ default:
+ fprintf(stderr, "Multicast for address family %x unsupported\n", ai->ai_family);
+ return 1;
}
errno = ENOENT;
struct addrinfo *ai2 = NULL;
+
if(getaddrinfo(argv[3], NULL, &hints, &ai2) || !ai2) {
fprintf(stderr, "Could not resolve %s: %s\n", argv[3], strerror(errno));
return 1;
uint8_t buf[10000];
struct sockaddr src;
socklen_t srclen;
- ssize_t len = recvfrom(fd, buf, sizeof buf, 0, &src, &srclen);
- if(len <= 0)
+ ssize_t len = recvfrom(fd, buf, sizeof(buf), 0, &src, &srclen);
+
+ if(len <= 0) {
break;
+ }
// Ignore short packets.
- if(len < 14)
+ if(len < 14) {
continue;
+ }
uint16_t type = buf[12] << 8 | buf[13];
- if(ai2->ai_family == AF_INET && type == ETH_P_IP)
+ if(ai2->ai_family == AF_INET && type == ETH_P_IP) {
len = do_ipv4(buf, len, (struct sockaddr_in *)ai2->ai_addr);
- else if(ai2->ai_family == AF_INET && type == ETH_P_ARP)
+ } else if(ai2->ai_family == AF_INET && type == ETH_P_ARP) {
len = do_arp(buf, len, (struct sockaddr_in *)ai2->ai_addr);
- else if(ai2->ai_family == AF_INET6 && type == ETH_P_IPV6)
+ } else if(ai2->ai_family == AF_INET6 && type == ETH_P_IPV6) {
len = do_ipv6(buf, len, (struct sockaddr_in6 *)ai2->ai_addr);
- else
+ } else {
continue;
+ }
- if(len > 0)
+ if(len > 0) {
sendto(fd, buf, len, 0, ai->ai_addr, ai->ai_addrlen);
+ }
}
return 0;
projects / tinc / blobdiff