diff options
Diffstat (limited to 'common/icmp.c')
| -rw-r--r-- | common/icmp.c | 308 |
1 files changed, 308 insertions, 0 deletions
diff --git a/common/icmp.c b/common/icmp.c new file mode 100644 index 0000000..cf9a745 --- /dev/null +++ b/common/icmp.c @@ -0,0 +1,308 @@ +/* dhcp.c + + ICMP Protocol engine - for sending out pings and receiving + responses. */ + +/* + * Copyright (c) 2011 by Internet Systems Consortium, Inc. ("ISC") + * Copyright (c) 2004,2007,2009 by Internet Systems Consortium, Inc. ("ISC") + * Copyright (c) 1996-2003 by Internet Software Consortium + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT + * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + * + * Internet Systems Consortium, Inc. + * 950 Charter Street + * Redwood City, CA 94063 + * <info@isc.org> + * https://www.isc.org/ + * + * This software has been written for Internet Systems Consortium + * by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc. + * To learn more about Internet Systems Consortium, see + * ``https://www.isc.org/''. To learn more about Vixie Enterprises, + * see ``http://www.vix.com''. To learn more about Nominum, Inc., see + * ``http://www.nominum.com''. + */ + +#include "dhcpd.h" +#include "netinet/ip.h" +#include "netinet/ip_icmp.h" + +struct icmp_state *icmp_state; +static omapi_object_type_t *dhcp_type_icmp; +static int no_icmp; + +OMAPI_OBJECT_ALLOC (icmp_state, struct icmp_state, dhcp_type_icmp) + +#if defined (TRACING) +trace_type_t *trace_icmp_input; +trace_type_t *trace_icmp_output; +#endif + +/* Initialize the ICMP protocol. */ + +void icmp_startup (routep, handler) + int routep; + void (*handler) (struct iaddr, u_int8_t *, int); +{ + struct protoent *proto; + int protocol = 1; + int state; + isc_result_t result; + + /* Only initialize icmp once. */ + if (dhcp_type_icmp) + log_fatal ("attempted to reinitialize icmp protocol"); + + result = omapi_object_type_register (&dhcp_type_icmp, "icmp", + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + sizeof (struct icmp_state), + 0, RC_MISC); + + if (result != ISC_R_SUCCESS) + log_fatal ("Can't register icmp object type: %s", + isc_result_totext (result)); + + icmp_state_allocate (&icmp_state, MDL); + icmp_state -> icmp_handler = handler; + +#if defined (TRACING) + trace_icmp_input = trace_type_register ("icmp-input", (void *)0, + trace_icmp_input_input, + trace_icmp_input_stop, MDL); + trace_icmp_output = trace_type_register ("icmp-output", (void *)0, + trace_icmp_output_input, + trace_icmp_output_stop, MDL); + + /* If we're playing back a trace file, don't create the socket + or set up the callback. */ + if (!trace_playback ()) { +#endif + /* Get the protocol number (should be 1). */ + proto = getprotobyname ("icmp"); + if (proto) + protocol = proto -> p_proto; + + /* Get a raw socket for the ICMP protocol. */ + icmp_state -> socket = socket (AF_INET, SOCK_RAW, protocol); + if (icmp_state -> socket < 0) { + no_icmp = 1; + log_error ("unable to create icmp socket: %m"); + return; + } + +#if defined (HAVE_SETFD) + if (fcntl (icmp_state -> socket, F_SETFD, 1) < 0) + log_error ("Can't set close-on-exec on icmp: %m"); +#endif + + /* Make sure it does routing... */ + state = 0; + if (setsockopt (icmp_state -> socket, SOL_SOCKET, SO_DONTROUTE, + (char *)&state, sizeof state) < 0) + log_fatal ("Can't disable SO_DONTROUTE on ICMP: %m"); + + result = (omapi_register_io_object + ((omapi_object_t *)icmp_state, + icmp_readsocket, 0, icmp_echoreply, 0, 0)); + if (result != ISC_R_SUCCESS) + log_fatal ("Can't register icmp handle: %s", + isc_result_totext (result)); +#if defined (TRACING) + } +#endif +} + +int icmp_readsocket (h) + omapi_object_t *h; +{ + struct icmp_state *state; + + state = (struct icmp_state *)h; + return state -> socket; +} + +int icmp_echorequest (addr) + struct iaddr *addr; +{ + struct sockaddr_in to; + struct icmp icmp; + int status; +#if defined (TRACING) + trace_iov_t iov [2]; +#endif + + if (no_icmp) + return 1; + if (!icmp_state) + log_fatal ("ICMP protocol used before initialization."); + + memset (&to, 0, sizeof(to)); +#ifdef HAVE_SA_LEN + to.sin_len = sizeof to; +#endif + to.sin_family = AF_INET; + to.sin_port = 0; /* unused. */ + memcpy (&to.sin_addr, addr -> iabuf, sizeof to.sin_addr); /* XXX */ + + icmp.icmp_type = ICMP_ECHO; + icmp.icmp_code = 0; + icmp.icmp_cksum = 0; + icmp.icmp_seq = 0; +#if SIZEOF_STRUCT_IADDR_P == 8 + icmp.icmp_id = (((u_int32_t)(u_int64_t)addr) ^ + (u_int32_t)(((u_int64_t)addr) >> 32)); +#else + icmp.icmp_id = (u_int32_t)addr; +#endif + memset (&icmp.icmp_dun, 0, sizeof icmp.icmp_dun); + + icmp.icmp_cksum = wrapsum (checksum ((unsigned char *)&icmp, + sizeof icmp, 0)); + +#if defined (TRACING) + if (trace_playback ()) { + char *buf = (char *)0; + unsigned buflen = 0; + + /* Consume the ICMP event. */ + status = trace_get_packet (&trace_icmp_output, &buflen, &buf); + if (status != ISC_R_SUCCESS) + log_error ("icmp_echorequest: %s", + isc_result_totext (status)); + if (buf) + dfree (buf, MDL); + } else { + if (trace_record ()) { + iov [0].buf = (char *)addr; + iov [0].len = sizeof *addr; + iov [1].buf = (char *)&icmp; + iov [1].len = sizeof icmp; + trace_write_packet_iov (trace_icmp_output, + 2, iov, MDL); + } +#endif + /* Send the ICMP packet... */ + status = sendto (icmp_state -> socket, + (char *)&icmp, sizeof icmp, 0, + (struct sockaddr *)&to, sizeof to); + if (status < 0) + log_error ("icmp_echorequest %s: %m", + inet_ntoa(to.sin_addr)); + + if (status != sizeof icmp) + return 0; +#if defined (TRACING) + } +#endif + return 1; +} + +isc_result_t icmp_echoreply (h) + omapi_object_t *h; +{ + struct icmp *icfrom; + struct ip *ip; + struct sockaddr_in from; + u_int8_t icbuf [1500]; + int status; + SOCKLEN_T sl; + int hlen, len; + struct iaddr ia; + struct icmp_state *state; +#if defined (TRACING) + trace_iov_t iov [2]; +#endif + + state = (struct icmp_state *)h; + + sl = sizeof from; + status = recvfrom (state -> socket, (char *)icbuf, sizeof icbuf, 0, + (struct sockaddr *)&from, &sl); + if (status < 0) { + log_error ("icmp_echoreply: %m"); + return ISC_R_UNEXPECTED; + } + + /* Find the IP header length... */ + ip = (struct ip *)icbuf; + hlen = IP_HL (ip); + + /* Short packet? */ + if (status < hlen + (sizeof *icfrom)) { + return ISC_R_SUCCESS; + } + + len = status - hlen; + icfrom = (struct icmp *)(icbuf + hlen); + + /* Silently discard ICMP packets that aren't echoreplies. */ + if (icfrom -> icmp_type != ICMP_ECHOREPLY) { + return ISC_R_SUCCESS; + } + + /* If we were given a second-stage handler, call it. */ + if (state -> icmp_handler) { + memcpy (ia.iabuf, &from.sin_addr, sizeof from.sin_addr); + ia.len = sizeof from.sin_addr; + +#if defined (TRACING) + if (trace_record ()) { + ia.len = htonl(ia.len); + iov [0].buf = (char *)&ia; + iov [0].len = sizeof ia; + iov [1].buf = (char *)icbuf; + iov [1].len = len; + trace_write_packet_iov (trace_icmp_input, 2, iov, MDL); + ia.len = ntohl(ia.len); + } +#endif + (*state -> icmp_handler) (ia, icbuf, len); + } + return ISC_R_SUCCESS; +} + +#if defined (TRACING) +void trace_icmp_input_input (trace_type_t *ttype, unsigned length, char *buf) +{ + struct iaddr *ia; + u_int8_t *icbuf; + ia = (struct iaddr *)buf; + ia->len = ntohl(ia->len); + icbuf = (u_int8_t *)(ia + 1); + if (icmp_state -> icmp_handler) + (*icmp_state -> icmp_handler) (*ia, icbuf, + (int)(length - sizeof ia)); +} + +void trace_icmp_input_stop (trace_type_t *ttype) { } + +void trace_icmp_output_input (trace_type_t *ttype, unsigned length, char *buf) +{ + struct icmp *icmp; + struct iaddr ia; + + if (length != (sizeof (*icmp) + (sizeof ia))) { + log_error ("trace_icmp_output_input: data size mismatch %d:%d", + length, (int)((sizeof (*icmp)) + (sizeof ia))); + return; + } + ia.len = 4; + memcpy (ia.iabuf, buf, 4); + icmp = (struct icmp *)(buf + 1); + + log_error ("trace_icmp_output_input: unsent ping to %s", piaddr (ia)); +} + +void trace_icmp_output_stop (trace_type_t *ttype) { } +#endif /* TRACING */ |