diff options
-rw-r--r-- | usr.sbin/traceroute/Makefile | 4 | ||||
-rw-r--r-- | usr.sbin/traceroute/findsaddr-udp.c | 94 |
2 files changed, 96 insertions, 2 deletions
diff --git a/usr.sbin/traceroute/Makefile b/usr.sbin/traceroute/Makefile index e73ff7f..6d6752a 100644 --- a/usr.sbin/traceroute/Makefile +++ b/usr.sbin/traceroute/Makefile @@ -5,7 +5,7 @@ TRACEROUTE_DISTDIR?= ${.CURDIR}/../../contrib/traceroute PROG= traceroute MAN= traceroute.8 -SRCS= as.c version.c traceroute.c ifaddrlist.c findsaddr-socket.c +SRCS= as.c version.c traceroute.c ifaddrlist.c findsaddr-udp.c BINOWN= root BINMODE=4555 CLEANFILES= version.c @@ -29,7 +29,7 @@ DPADD= ${LIBIPSEC} LDADD= -lipsec .endif -CFLAGS+= -I${TRACEROUTE_DISTDIR}/lbl +CFLAGS+= -I${TRACEROUTE_DISTDIR}/lbl -I${TRACEROUTE_DISTDIR} WARNS?= 0 diff --git a/usr.sbin/traceroute/findsaddr-udp.c b/usr.sbin/traceroute/findsaddr-udp.c new file mode 100644 index 0000000..3af5d53 --- /dev/null +++ b/usr.sbin/traceroute/findsaddr-udp.c @@ -0,0 +1,94 @@ +/*- + * Copyright (c) 2010 Bjoern A. Zeeb <bz@FreeBSD.org> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD$ + */ + +#include <string.h> +#include <unistd.h> + +#include <sys/types.h> +#include <sys/socket.h> + +#include <netinet/in.h> + +#include "findsaddr.h" +#include "traceroute.h" + +/* + * Return the source address for the given destination address. + * + * This makes use of proper source address seclection in the FreeBSD kernel + * even taking jails into account (sys/netinet/in_pcb.c:in_pcbladdr()). + * We open a UDP socket, and connect to the destination, letting the kernel + * do the bind and then read the source IPv4 address using getsockname(2). + * This has multiple advantages: no need to do PF_ROUTE operations possibly + * needing special privileges, jails properly taken into account and most + * important - getting the result the kernel would give us rather than + * best-guessing ourselves. + */ +const char * +findsaddr(register const struct sockaddr_in *to, + register struct sockaddr_in *from) +{ + const char *errstr; + struct sockaddr_in cto, cfrom; + int s; + socklen_t len; + + s = socket(AF_INET, SOCK_DGRAM, 0); + if (s == -1) + return ("failed to open DGRAM socket for src addr selection."); + + errstr = NULL; + len = sizeof(struct sockaddr_in); + memcpy(&cto, to, len); + cto.sin_port = htons(65535); /* Dummy port for connect(2). */ + if (connect(s, (struct sockaddr *)&cto, len) == -1) { + errstr = "failed to connect to peer for src addr selection."; + goto err; + } + + if (getsockname(s, (struct sockaddr *)&cfrom, &len) == -1) { + errstr = "failed to get socket name for src addr selection."; + goto err; + } + + if (len != sizeof(struct sockaddr_in) || cfrom.sin_family != AF_INET) { + errstr = "unexpected address family in src addr selection."; + goto err; + } + + /* Update source address for traceroute. */ + setsin(from, cfrom.sin_addr.s_addr); + +err: + (void) close(s); + + /* No error (string) to return. */ + return (errstr); +} + +/* end */ |