--- gvpe/src/vpn.C 2003/04/07 01:28:56 1.8 +++ gvpe/src/vpn.C 2003/04/08 02:00:54 1.9 @@ -28,11 +28,12 @@ #include #include #include -#include -#include #include #include #include +#include +#include +#include #include "pidfile.h" @@ -82,14 +83,6 @@ if (ipv4_fd < 0) return -1; - sockinfo si (THISNODE, PROT_IPv4); - - if (bind (ipv4_fd, si.sav4 (), si.salenv4 ())) - { - slog (L_ERR, _("can't bind ipv4 socket on %s: %s"), (const char *)si, strerror (errno)); - exit (1); - } - #ifdef IP_MTU_DISCOVER // this I really consider a linux bug. I am neither connected // nor do I fragment myself. Linux still sets DF and doesn't @@ -100,6 +93,14 @@ } #endif + sockinfo si (THISNODE, PROT_IPv4); + + if (bind (ipv4_fd, si.sav4 (), si.salenv4 ())) + { + slog (L_ERR, _("can't bind ipv4 socket on %s: %s"), (const char *)si, strerror (errno)); + exit (1); + } + ipv4_ev_watcher.start (ipv4_fd, POLLIN); } @@ -118,6 +119,16 @@ setsockopt (udpv4_fd, SOL_SOCKET, SO_REUSEADDR, &oval, sizeof oval); } +#ifdef IP_MTU_DISCOVER + // this I really consider a linux bug. I am neither connected + // nor do I fragment myself. Linux still sets DF and doesn't + // fragment for me sometimes. + { + int oval = IP_PMTUDISC_DONT; + setsockopt (udpv4_fd, SOL_IP, IP_MTU_DISCOVER, &oval, sizeof oval); + } +#endif + sockinfo si (THISNODE, PROT_UDPv4); if (bind (udpv4_fd, si.sav4 (), si.salenv4 ())) @@ -126,6 +137,30 @@ exit (1); } + udpv4_ev_watcher.start (udpv4_fd, POLLIN); + } + + icmpv4_fd = -1; + +#if ENABLE_ICMP + if (THISNODE->protocols & PROT_ICMPv4) + { + icmpv4_fd = socket (PF_INET, SOCK_RAW, IPPROTO_ICMP); + + if (icmpv4_fd < 0) + return -1; + +#ifdef ICMP_FILTER + { + icmp_filter oval; + oval.data = 0xffffffff; + if (::conf.icmp_type < 32) + oval.data &= ~(1 << ::conf.icmp_type); + + setsockopt (icmpv4_fd, SOL_RAW, ICMP_FILTER, &oval, sizeof oval); + } +#endif + #ifdef IP_MTU_DISCOVER // this I really consider a linux bug. I am neither connected // nor do I fragment myself. Linux still sets DF and doesn't @@ -136,8 +171,17 @@ } #endif - udpv4_ev_watcher.start (udpv4_fd, POLLIN); + sockinfo si (THISNODE, PROT_ICMPv4); + + if (bind (icmpv4_fd, si.sav4 (), si.salenv4 ())) + { + slog (L_ERR, _("can't bind icmpv4 on %s: %s"), (const char *)si, strerror (errno)); + exit (1); + } + + icmpv4_ev_watcher.start (icmpv4_fd, POLLIN); } +#endif tcpv4_fd = -1; @@ -206,6 +250,11 @@ return send_tcpv4_packet (pkt, si, tos); #endif +#if ENABLE_ICMP + case PROT_ICMPv4: + return send_icmpv4_packet (pkt, si, tos); +#endif + default: slog (L_CRIT, _("%s: FATAL: trying to send packet with unsupported protocol"), (const char *)si); return false; @@ -221,6 +270,47 @@ return true; } +static u16 +ipv4_checksum (u16 *data, unsigned int len) +{ + // use 32 bit accumulator and fold back carry bits at the end + u32 sum = 0; + + while (len > 1) + { + sum += *data++; + len -= 2; + } + + // odd byte left? + if (len) + sum += *(u8 *)data; + + // add back carry bits + sum = (sum >> 16) + (sum & 0xffff); // lo += hi + sum += (sum >> 16); // carry + + return ~sum; +} + +bool +vpn::send_icmpv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) +{ + setsockopt (icmpv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos); + + pkt->unshift_hdr (4); + + icmphdr *hdr = (icmphdr *)&((*pkt)[0]); + hdr->type = ::conf.icmp_type; + hdr->code = 255; + hdr->checksum = 0; + hdr->checksum = ipv4_checksum ((u16 *)hdr, pkt->len); + + sendto (icmpv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ()); + + return true; +} + bool vpn::send_udpv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) { @@ -271,7 +361,7 @@ } void -vpn::udpv4_ev (io_watcher &w, short revents) +vpn::ipv4_ev (io_watcher &w, short revents) { if (revents & (POLLIN | POLLERR)) { @@ -282,18 +372,22 @@ len = recvfrom (w.fd, &((*pkt)[0]), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); - sockinfo si(sa, PROT_UDPv4); + sockinfo si(sa, PROT_IPv4); if (len > 0) { pkt->len = len; + // raw sockets deliver the ipv4, but don't expect it on sends + // this is slow, but... + pkt->skip_hdr (IP_OVERHEAD); + recv_vpn_packet (pkt, si); } else { // probably ECONNRESET or somesuch - slog (L_DEBUG, _("%s: fd %d, %s"), (const char *)si, w.fd, strerror (errno)); + slog (L_DEBUG, _("%s: %s"), (const char *)si, strerror (errno)); } delete pkt; @@ -301,7 +395,7 @@ else if (revents & POLLHUP) { // this cannot ;) happen on udp sockets - slog (L_ERR, _("FATAL: POLLHUP on udp v4 fd, terminating.")); + slog (L_ERR, _("FATAL: POLLHUP on ipv4 fd, terminating.")); exit (1); } else @@ -314,7 +408,7 @@ } void -vpn::ipv4_ev (io_watcher &w, short revents) +vpn::icmpv4_ev (io_watcher &w, short revents) { if (revents & (POLLIN | POLLERR)) { @@ -325,17 +419,23 @@ len = recvfrom (w.fd, &((*pkt)[0]), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); - sockinfo si(sa, PROT_IPv4); + sockinfo si(sa, PROT_ICMPv4); if (len > 0) { pkt->len = len; - // raw sockets deliver the ipv4, but don't expect it on sends - // this is slow, but... - pkt->skip_hdr (IP_OVERHEAD); + icmphdr *hdr = (icmphdr *)&((*pkt)[IP_OVERHEAD]); - recv_vpn_packet (pkt, si); + if (hdr->type == ::conf.icmp_type + && hdr->code == 255) + { + // raw sockets deliver the ipv4, but don't expect it on sends + // this is slow, but... + pkt->skip_hdr (ICMP_OVERHEAD); + + recv_vpn_packet (pkt, si); + } } else { @@ -348,7 +448,50 @@ else if (revents & POLLHUP) { // this cannot ;) happen on udp sockets - slog (L_ERR, _("FATAL: POLLHUP on ipv4 fd, terminating.")); + slog (L_ERR, _("FATAL: POLLHUP on icmpv4 fd, terminating.")); + exit (1); + } + else + { + slog (L_ERR, + _("FATAL: unknown revents %08x in socket, terminating\n"), + revents); + exit (1); + } +} + +void +vpn::udpv4_ev (io_watcher &w, short revents) +{ + if (revents & (POLLIN | POLLERR)) + { + vpn_packet *pkt = new vpn_packet; + struct sockaddr_in sa; + socklen_t sa_len = sizeof (sa); + int len; + + len = recvfrom (w.fd, &((*pkt)[0]), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); + + sockinfo si(sa, PROT_UDPv4); + + if (len > 0) + { + pkt->len = len; + + recv_vpn_packet (pkt, si); + } + else + { + // probably ECONNRESET or somesuch + slog (L_DEBUG, _("%s: fd %d, %s"), (const char *)si, w.fd, strerror (errno)); + } + + delete pkt; + } + else if (revents & POLLHUP) + { + // this cannot ;) happen on udp sockets + slog (L_ERR, _("FATAL: POLLHUP on udp v4 fd, terminating.")); exit (1); } else @@ -539,13 +682,16 @@ } vpn::vpn (void) -: event(this, &vpn::event_cb) -, udpv4_ev_watcher(this, &vpn::udpv4_ev) -, ipv4_ev_watcher (this, &vpn::ipv4_ev) -, tap_ev_watcher (this, &vpn::tap_ev) +: event (this, &vpn::event_cb) +, udpv4_ev_watcher (this, &vpn::udpv4_ev) +, ipv4_ev_watcher (this, &vpn::ipv4_ev) #if ENABLE_TCP -, tcpv4_ev_watcher(this, &vpn::tcpv4_ev) +, tcpv4_ev_watcher (this, &vpn::tcpv4_ev) +#endif +#if ENABLE_ICMP +, icmpv4_ev_watcher(this, &vpn::icmpv4_ev) #endif +, tap_ev_watcher (this, &vpn::tap_ev) { }