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freebsd-dev/contrib/libpcap/inet.c

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/* -*- Mode: c; tab-width: 8; indent-tabs-mode: 1; c-basic-offset: 8; -*- */
/*
* Copyright (c) 1994, 1995, 1996, 1997, 1998
* The Regents of the University of California. 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the Computer Systems
* Engineering Group at Lawrence Berkeley Laboratory.
* 4. Neither the name of the University nor of the Laboratory may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*/
#ifndef lint
static const char rcsid[] =
"@(#) $Header: /tcpdump/master/libpcap/inet.c,v 1.45 2001/10/28 20:40:43 guy Exp $ (LBL)";
#endif
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <sys/param.h>
#include <sys/file.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#ifdef HAVE_SYS_SOCKIO_H
#include <sys/sockio.h>
#endif
#include <sys/time.h> /* concession to AIX */
struct mbuf;
struct rtentry;
#include <net/if.h>
#include <netinet/in.h>
#include <ctype.h>
#include <errno.h>
#include <memory.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#ifdef HAVE_LIMITS_H
#include <limits.h>
#else
#define INT_MAX 2147483647
#endif
#ifdef HAVE_IFADDRS_H
#include <ifaddrs.h>
#endif
#include "pcap-int.h"
#ifdef HAVE_OS_PROTO_H
#include "os-proto.h"
#endif
/* Not all systems have IFF_LOOPBACK */
#ifdef IFF_LOOPBACK
#define ISLOOPBACK(name, flags) ((flags) & IFF_LOOPBACK)
#else
#define ISLOOPBACK(name, flags) ((name)[0] == 'l' && (name)[1] == 'o' && \
(isdigit((unsigned char)((name)[2])) || (name)[2] == '\0'))
#endif
/*
* This is fun.
*
* In older BSD systems, socket addresses were fixed-length, and
* "sizeof (struct sockaddr)" gave the size of the structure.
* All addresses fit within a "struct sockaddr".
*
* In newer BSD systems, the socket address is variable-length, and
* there's an "sa_len" field giving the length of the structure;
* this allows socket addresses to be longer than 2 bytes of family
* and 14 bytes of data.
*
* Some commercial UNIXes use the old BSD scheme, and some might use
* the new BSD scheme.
*
* GNU libc uses neither scheme, but has an "SA_LEN()" macro that
* determines the size based on the address family.
*/
#ifndef SA_LEN
#ifdef HAVE_SOCKADDR_SA_LEN
#define SA_LEN(addr) ((addr)->sa_len)
#else /* HAVE_SOCKADDR_SA_LEN */
#define SA_LEN(addr) (sizeof (struct sockaddr))
#endif /* HAVE_SOCKADDR_SA_LEN */
#endif /* SA_LEN */
/*
* Description string for the "any" device.
*/
static const char any_descr[] = "Pseudo-device that captures on all interfaces";
static struct sockaddr *
dup_sockaddr(struct sockaddr *sa)
{
struct sockaddr *newsa;
unsigned int size;
size = SA_LEN(sa);
if ((newsa = malloc(size)) == NULL)
return (NULL);
return (memcpy(newsa, sa, size));
}
static int
get_instance(char *name)
{
char *cp, *endcp;
int n;
if (strcmp(name, "any") == 0) {
/*
* Give the "any" device an artificially high instance
* number, so it shows up after all other non-loopback
* interfaces.
*/
return INT_MAX;
}
endcp = name + strlen(name);
for (cp = name; cp < endcp && !isdigit((unsigned char)*cp); ++cp)
continue;
if (isdigit((unsigned char)*cp))
n = atoi(cp);
else
n = 0;
return (n);
}
static int
add_or_find_if(pcap_if_t **curdev_ret, pcap_if_t **alldevs, char *name,
u_int flags, const char *description, char *errbuf)
{
pcap_t *p;
pcap_if_t *curdev, *prevdev, *nextdev;
int this_instance;
/*
* Can we open this interface for live capture?
*/
p = pcap_open_live(name, 68, 0, 0, errbuf);
if (p == NULL) {
/*
* No. Don't bother including it.
* Don't treat this as an error, though.
*/
*curdev_ret = NULL;
return (0);
}
pcap_close(p);
/*
* Is there already an entry in the list for this interface?
*/
for (curdev = *alldevs; curdev != NULL; curdev = curdev->next) {
if (strcmp(name, curdev->name) == 0)
break; /* yes, we found it */
}
if (curdev == NULL) {
/*
* No, we didn't find it.
* Allocate a new entry.
*/
curdev = malloc(sizeof(pcap_if_t));
if (curdev == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc: %s", pcap_strerror(errno));
return (-1);
}
/*
* Fill in the entry.
*/
curdev->next = NULL;
curdev->name = malloc(strlen(name) + 1);
strcpy(curdev->name, name);
if (description != NULL) {
/*
* We have a description for this interface.
*/
curdev->description = malloc(strlen(description) + 1);
strcpy(curdev->description, description);
} else {
/*
* We don't.
*/
curdev->description = NULL;
}
curdev->addresses = NULL; /* list starts out as empty */
curdev->flags = 0;
if (ISLOOPBACK(name, flags))
curdev->flags |= PCAP_IF_LOOPBACK;
/*
* Add it to the list, in the appropriate location.
* First, get the instance number of this interface.
*/
this_instance = get_instance(name);
/*
* Now look for the last interface with an instance number
* less than or equal to the new interface's instance
* number - except that non-loopback interfaces are
* arbitrarily treated as having interface numbers less
* than those of loopback interfaces, so the loopback
* interfaces are put at the end of the list.
*
* We start with "prevdev" being NULL, meaning we're before
* the first element in the list.
*/
prevdev = NULL;
for (;;) {
/*
* Get the interface after this one.
*/
if (prevdev == NULL) {
/*
* The next element is the first element.
*/
nextdev = *alldevs;
} else
nextdev = prevdev->next;
/*
* Are we at the end of the list?
*/
if (nextdev == NULL) {
/*
* Yes - we have to put the new entry
* after "prevdev".
*/
break;
}
/*
* Is the new interface a non-loopback interface
* and the next interface a loopback interface?
*/
if (!(curdev->flags & PCAP_IF_LOOPBACK) &&
(nextdev->flags & PCAP_IF_LOOPBACK)) {
/*
* Yes, we should put the new entry
* before "nextdev", i.e. after "prevdev".
*/
break;
}
/*
* Is the new interface's instance number less
* than the next interface's instance number,
* and is it the case that the new interface is a
* non-loopback interface or the next interface is
* a loopback interface?
*
* (The goal of both loopback tests is to make
* sure that we never put a loopback interface
* before any non-loopback interface and that we
* always put a non-loopback interface before all
* loopback interfaces.)
*/
if (this_instance < get_instance(nextdev->name) &&
(!(curdev->flags & PCAP_IF_LOOPBACK) ||
(nextdev->flags & PCAP_IF_LOOPBACK))) {
/*
* Yes - we should put the new entry
* before "nextdev", i.e. after "prevdev".
*/
break;
}
prevdev = nextdev;
}
/*
* Insert before "nextdev".
*/
curdev->next = nextdev;
/*
* Insert after "prevdev" - unless "prevdev" is null,
* in which case this is the first interface.
*/
if (prevdev == NULL) {
/*
* This is the first interface. Pass back a
* pointer to it, and put "curdev" before
* "nextdev".
*/
*alldevs = curdev;
} else
prevdev->next = curdev;
}
*curdev_ret = curdev;
return (0);
}
static int
add_addr_to_iflist(pcap_if_t **alldevs, char *name, u_int flags,
struct sockaddr *addr, struct sockaddr *netmask,
struct sockaddr *broadaddr, struct sockaddr *dstaddr, char *errbuf)
{
pcap_if_t *curdev;
pcap_addr_t *curaddr, *prevaddr, *nextaddr;
if (add_or_find_if(&curdev, alldevs, name, flags, NULL, errbuf) == -1) {
/*
* Error - give up.
*/
return (-1);
}
if (curdev == NULL) {
/*
* Device wasn't added because it can't be opened.
* Not a fatal error.
*/
return (0);
}
/*
* "curdev" is an entry for this interface; add an entry for this
* address to its list of addresses.
*
* Allocate the new entry and fill it in.
*/
curaddr = malloc(sizeof(pcap_addr_t));
if (curaddr == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc: %s", pcap_strerror(errno));
return (-1);
}
curaddr->next = NULL;
if (addr != NULL) {
curaddr->addr = dup_sockaddr(addr);
if (curaddr->addr == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc: %s", pcap_strerror(errno));
free(curaddr);
return (-1);
}
} else
curaddr->addr = NULL;
if (netmask != NULL) {
curaddr->netmask = dup_sockaddr(netmask);
if (curaddr->netmask == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc: %s", pcap_strerror(errno));
free(curaddr);
return (-1);
}
} else
curaddr->netmask = NULL;
if (broadaddr != NULL) {
curaddr->broadaddr = dup_sockaddr(broadaddr);
if (curaddr->broadaddr == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc: %s", pcap_strerror(errno));
free(curaddr);
return (-1);
}
} else
curaddr->broadaddr = NULL;
if (dstaddr != NULL) {
curaddr->dstaddr = dup_sockaddr(dstaddr);
if (curaddr->dstaddr == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc: %s", pcap_strerror(errno));
free(curaddr);
return (-1);
}
} else
curaddr->dstaddr = NULL;
/*
* Find the end of the list of addresses.
*/
for (prevaddr = curdev->addresses; prevaddr != NULL; prevaddr = nextaddr) {
nextaddr = prevaddr->next;
if (nextaddr == NULL) {
/*
* This is the end of the list.
*/
break;
}
}
if (prevaddr == NULL) {
/*
* The list was empty; this is the first member.
*/
curdev->addresses = curaddr;
} else {
/*
* "prevaddr" is the last member of the list; append
* this member to it.
*/
prevaddr->next = curaddr;
}
return (0);
}
static int
pcap_add_if(pcap_if_t **devlist, char *name, u_int flags,
const char *description, char *errbuf)
{
pcap_if_t *curdev;
return (add_or_find_if(&curdev, devlist, name, flags, description,
errbuf));
}
/*
* Get a list of all interfaces that are up and that we can open.
* Returns -1 on error, 0 otherwise.
* The list, as returned through "alldevsp", may be null if no interfaces
* were up and could be opened.
*/
#ifdef HAVE_IFADDRS_H
int
pcap_findalldevs(pcap_if_t **alldevsp, char *errbuf)
{
pcap_if_t *devlist = NULL;
struct ifaddrs *ifap, *ifa;
struct sockaddr *broadaddr, *dstaddr;
int ret = 0;
/*
* Get the list of interface addresses.
*
* Note: this won't return information about interfaces
* with no addresses; are there any such interfaces
* that would be capable of receiving packets?
* (Interfaces incapable of receiving packets aren't
* very interesting from libpcap's point of view.)
*
* LAN interfaces will probably have link-layer
* addresses; I don't know whether all implementations
* of "getifaddrs()" now, or in the future, will return
* those.
*/
if (getifaddrs(&ifap) != 0) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"getifaddrs: %s", pcap_strerror(errno));
return (-1);
}
for (ifa = ifap; ifa != NULL; ifa = ifa->ifa_next) {
/*
* Is this interface up?
*/
if (!(ifa->ifa_flags & IFF_UP)) {
/*
* No, so don't add it to the list.
*/
continue;
}
/*
* "ifa_broadaddr" may be non-null even on
* non-broadcast interfaces; "ifa_dstaddr"
* was, on at least one FreeBSD 4.1 system,
* non-null on a non-point-to-point
* interface.
*/
if (ifa->ifa_flags & IFF_BROADCAST)
broadaddr = ifa->ifa_broadaddr;
else
broadaddr = NULL;
if (ifa->ifa_flags & IFF_POINTOPOINT)
dstaddr = ifa->ifa_dstaddr;
else
dstaddr = NULL;
/*
* Add information for this address to the list.
*/
if (add_addr_to_iflist(&devlist, ifa->ifa_name,
ifa->ifa_flags, ifa->ifa_addr, ifa->ifa_netmask,
broadaddr, dstaddr, errbuf) < 0) {
ret = -1;
break;
}
}
freeifaddrs(ifap);
if (ret != -1) {
/*
* We haven't had any errors yet; add the "any" device,
* if we can open it.
*/
if (pcap_add_if(&devlist, "any", 0, any_descr, errbuf) < 0)
ret = -1;
}
if (ret == -1) {
/*
* We had an error; free the list we've been constructing.
*/
if (devlist != NULL) {
pcap_freealldevs(devlist);
devlist = NULL;
}
}
*alldevsp = devlist;
return (ret);
}
#else /* HAVE_IFADDRS_H */
#ifdef HAVE_PROC_NET_DEV
/*
* Get from "/proc/net/dev" all interfaces listed there; if they're
* already in the list of interfaces we have, that won't add another
* instance, but if they're not, that'll add them.
*
* We don't bother getting any addresses for them; it appears you can't
* use SIOCGIFADDR on Linux to get IPv6 addresses for interfaces, and,
* although some other types of addresses can be fetched with SIOCGIFADDR,
* we don't bother with them for now.
*
* We also don't fail if we couldn't open "/proc/net/dev"; we just leave
* the list of interfaces as is.
*/
static int
scan_proc_net_dev(pcap_if_t **devlistp, int fd, char *errbuf)
{
FILE *proc_net_f;
char linebuf[512];
int linenum;
unsigned char *p;
char name[512]; /* XXX - pick a size */
char *q, *saveq;
struct ifreq ifrflags;
int ret = 0;
proc_net_f = fopen("/proc/net/dev", "r");
if (proc_net_f == NULL)
return (0);
for (linenum = 1;
fgets(linebuf, sizeof linebuf, proc_net_f) != NULL; linenum++) {
/*
* Skip the first two lines - they're headers.
*/
if (linenum <= 2)
continue;
p = &linebuf[0];
/*
* Skip leading white space.
*/
while (*p != '\0' && isspace(*p))
p++;
if (*p == '\0' || *p == '\n')
continue; /* blank line */
/*
* Get the interface name.
*/
q = &name[0];
while (*p != '\0' && !isspace(*p)) {
if (*p == ':') {
/*
* This could be the separator between a
* name and an alias number, or it could be
* the separator between a name with no
* alias number and the next field.
*
* If there's a colon after digits, it
* separates the name and the alias number,
* otherwise it separates the name and the
* next field.
*/
saveq = q;
while (isdigit(*p))
*q++ = *p++;
if (*p != ':') {
/*
* That was the next field,
* not the alias number.
*/
q = saveq;
}
break;
} else
*q++ = *p++;
}
*q = '\0';
/*
* Get the flags for this interface, and skip it if
* it's not up.
*/
strncpy(ifrflags.ifr_name, name, sizeof(ifrflags.ifr_name));
if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifrflags) < 0) {
if (errno == ENXIO)
continue;
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"SIOCGIFFLAGS: %.*s: %s",
(int)sizeof(ifrflags.ifr_name),
ifrflags.ifr_name,
pcap_strerror(errno));
ret = -1;
break;
}
if (!(ifrflags.ifr_flags & IFF_UP))
continue;
/*
* Add an entry for this interface, with no addresses.
*/
if (pcap_add_if(devlistp, name, ifrflags.ifr_flags, NULL,
errbuf) == -1) {
/*
* Failure.
*/
ret = -1;
break;
}
}
if (ret != -1) {
/*
* Well, we didn't fail for any other reason; did we
* fail due to an error reading the file?
*/
if (ferror(proc_net_f)) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"Error reading /proc/net/dev: %s",
pcap_strerror(errno));
ret = -1;
}
}
(void)fclose(proc_net_f);
return (ret);
}
#endif /* HAVE_PROC_NET_DEV */
int
pcap_findalldevs(pcap_if_t **alldevsp, char *errbuf)
{
pcap_if_t *devlist = NULL;
register int fd;
register struct ifreq *ifrp, *ifend, *ifnext;
int n;
struct ifconf ifc;
char *buf = NULL;
unsigned buf_size;
struct ifreq ifrflags, ifrnetmask, ifrbroadaddr, ifrdstaddr;
struct sockaddr *netmask, *broadaddr, *dstaddr;
int ret = 0;
/*
* Create a socket from which to fetch the list of interfaces.
*/
fd = socket(AF_INET, SOCK_DGRAM, 0);
if (fd < 0) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"socket: %s", pcap_strerror(errno));
return (-1);
}
/*
* Start with an 8K buffer, and keep growing the buffer until
* we get the entire interface list or fail to get it for some
* reason other than EINVAL (which is presumed here to mean
* "buffer is too small").
*/
buf_size = 8192;
for (;;) {
buf = malloc(buf_size);
if (buf == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc: %s", pcap_strerror(errno));
(void)close(fd);
return (-1);
}
ifc.ifc_len = buf_size;
ifc.ifc_buf = buf;
memset(buf, 0, buf_size);
if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0
&& errno != EINVAL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"SIOCGIFCONF: %s", pcap_strerror(errno));
(void)close(fd);
free(buf);
return (-1);
}
if (ifc.ifc_len < buf_size)
break;
free(buf);
buf_size *= 2;
}
ifrp = (struct ifreq *)buf;
ifend = (struct ifreq *)(buf + ifc.ifc_len);
for (; ifrp < ifend; ifrp = ifnext) {
n = SA_LEN(&ifrp->ifr_addr) + sizeof(ifrp->ifr_name);
if (n < sizeof(*ifrp))
ifnext = ifrp + 1;
else
ifnext = (struct ifreq *)((char *)ifrp + n);
/*
* Get the flags for this interface, and skip it if it's
* not up.
*/
strncpy(ifrflags.ifr_name, ifrp->ifr_name,
sizeof(ifrflags.ifr_name));
if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifrflags) < 0) {
if (errno == ENXIO)
continue;
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"SIOCGIFFLAGS: %.*s: %s",
(int)sizeof(ifrflags.ifr_name),
ifrflags.ifr_name,
pcap_strerror(errno));
ret = -1;
break;
}
if (!(ifrflags.ifr_flags & IFF_UP))
continue;
/*
* Get the netmask for this address on this interface.
*/
strncpy(ifrnetmask.ifr_name, ifrp->ifr_name,
sizeof(ifrnetmask.ifr_name));
memcpy(&ifrnetmask.ifr_addr, &ifrp->ifr_addr,
sizeof(ifrnetmask.ifr_addr));
if (ioctl(fd, SIOCGIFNETMASK, (char *)&ifrnetmask) < 0) {
if (errno == EADDRNOTAVAIL) {
/*
* Not available.
*/
netmask = NULL;
} else {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"SIOCGIFNETMASK: %.*s: %s",
(int)sizeof(ifrnetmask.ifr_name),
ifrnetmask.ifr_name,
pcap_strerror(errno));
ret = -1;
break;
}
} else
netmask = &ifrnetmask.ifr_addr;
/*
* Get the broadcast address for this address on this
* interface (if any).
*/
if (ifrflags.ifr_flags & IFF_BROADCAST) {
strncpy(ifrbroadaddr.ifr_name, ifrp->ifr_name,
sizeof(ifrbroadaddr.ifr_name));
memcpy(&ifrbroadaddr.ifr_addr, &ifrp->ifr_addr,
sizeof(ifrbroadaddr.ifr_addr));
if (ioctl(fd, SIOCGIFBRDADDR,
(char *)&ifrbroadaddr) < 0) {
if (errno == EADDRNOTAVAIL) {
/*
* Not available.
*/
broadaddr = NULL;
} else {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"SIOCGIFBRDADDR: %.*s: %s",
(int)sizeof(ifrbroadaddr.ifr_name),
ifrbroadaddr.ifr_name,
pcap_strerror(errno));
ret = -1;
break;
}
} else
broadaddr = &ifrbroadaddr.ifr_broadaddr;
} else {
/*
* Not a broadcast interface, so no broadcast
* address.
*/
broadaddr = NULL;
}
/*
* Get the destination address for this address on this
* interface (if any).
*/
if (ifrflags.ifr_flags & IFF_POINTOPOINT) {
strncpy(ifrdstaddr.ifr_name, ifrp->ifr_name,
sizeof(ifrdstaddr.ifr_name));
memcpy(&ifrdstaddr.ifr_addr, &ifrp->ifr_addr,
sizeof(ifrdstaddr.ifr_addr));
if (ioctl(fd, SIOCGIFDSTADDR,
(char *)&ifrdstaddr) < 0) {
if (errno == EADDRNOTAVAIL) {
/*
* Not available.
*/
dstaddr = NULL;
} else {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"SIOCGIFDSTADDR: %.*s: %s",
(int)sizeof(ifrdstaddr.ifr_name),
ifrdstaddr.ifr_name,
pcap_strerror(errno));
ret = -1;
break;
}
} else
dstaddr = &ifrdstaddr.ifr_dstaddr;
} else
dstaddr = NULL;
/*
* Add information for this address to the list.
*/
if (add_addr_to_iflist(&devlist, ifrp->ifr_name,
ifrflags.ifr_flags, &ifrp->ifr_addr,
netmask, broadaddr, dstaddr, errbuf) < 0) {
ret = -1;
break;
}
}
free(buf);
#ifdef HAVE_PROC_NET_DEV
if (ret != -1) {
/*
* We haven't had any errors yet; now read "/proc/net/dev",
* and add to the list of interfaces all interfaces listed
* there that we don't already have, because, on Linux,
* SIOCGIFCONF reports only interfaces with IPv4 addresses,
* so you need to read "/proc/net/dev" to get the names of
* the rest of the interfaces.
*/
ret = scan_proc_net_dev(&devlist, fd, errbuf);
}
#endif
(void)close(fd);
if (ret != -1) {
/*
* We haven't had any errors yet; add the "any" device,
* if we can open it.
*/
if (pcap_add_if(&devlist, "any", 0, any_descr, errbuf) < 0) {
/*
* Oops, we had a fatal error.
*/
ret = -1;
}
}
if (ret == -1) {
/*
* We had an error; free the list we've been constructing.
*/
if (devlist != NULL) {
pcap_freealldevs(devlist);
devlist = NULL;
}
}
*alldevsp = devlist;
return (ret);
}
#endif /* HAVE_IFADDRS_H */
/*
* Free a list of interfaces.
*/
void
pcap_freealldevs(pcap_if_t *alldevs)
{
pcap_if_t *curdev, *nextdev;
pcap_addr_t *curaddr, *nextaddr;
for (curdev = alldevs; curdev != NULL; curdev = nextdev) {
nextdev = curdev->next;
/*
* Free all addresses.
*/
for (curaddr = curdev->addresses; curaddr != NULL; curaddr = nextaddr) {
nextaddr = curaddr->next;
if (curaddr->addr)
free(curaddr->addr);
if (curaddr->netmask)
free(curaddr->netmask);
if (curaddr->broadaddr)
free(curaddr->broadaddr);
if (curaddr->dstaddr)
free(curaddr->dstaddr);
free(curaddr);
}
/*
* Free the name string.
*/
free(curdev->name);
/*
* Free the description string, if any.
*/
if (curdev->description != NULL)
free(curdev->description);
/*
* Free the interface.
*/
free(curdev);
}
}
/*
* Return the name of a network interface attached to the system, or NULL
* if none can be found. The interface must be configured up; the
* lowest unit number is preferred; loopback is ignored.
*/
char *
pcap_lookupdev(errbuf)
register char *errbuf;
{
pcap_if_t *alldevs;
/* for old BSD systems, including bsdi3 */
#ifndef IF_NAMESIZE
#define IF_NAMESIZE IFNAMSIZ
#endif
static char device[IF_NAMESIZE + 1];
char *ret;
if (pcap_findalldevs(&alldevs, errbuf) == -1)
return (NULL);
if (alldevs == NULL || (alldevs->flags & PCAP_IF_LOOPBACK)) {
/*
* There are no devices on the list, or the first device
* on the list is a loopback device, which means there
* are no non-loopback devices on the list. This means
* we can't return any device.
*
* XXX - why not return a loopback device? If we can't
* capture on it, it won't be on the list, and if it's
* on the list, there aren't any non-loopback devices,
* so why not just supply it as the default device?
*/
(void)strlcpy(errbuf, "no suitable device found",
PCAP_ERRBUF_SIZE);
ret = NULL;
} else {
/*
* Return the name of the first device on the list.
*/
(void)strlcpy(device, alldevs->name, sizeof(device));
ret = device;
}
pcap_freealldevs(alldevs);
return (ret);
}
int
pcap_lookupnet(device, netp, maskp, errbuf)
register char *device;
register bpf_u_int32 *netp, *maskp;
register char *errbuf;
{
register int fd;
register struct sockaddr_in *sin;
struct ifreq ifr;
/*
* The pseudo-device "any" listens on all interfaces and therefore
* has the network address and -mask "0.0.0.0" therefore catching
* all traffic. Using NULL for the interface is the same as "any".
*/
if (!device || strcmp(device, "any") == 0) {
*netp = *maskp = 0;
return 0;
}
fd = socket(AF_INET, SOCK_DGRAM, 0);
if (fd < 0) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE, "socket: %s",
pcap_strerror(errno));
return (-1);
}
memset(&ifr, 0, sizeof(ifr));
#ifdef linux
/* XXX Work around Linux kernel bug */
ifr.ifr_addr.sa_family = AF_INET;
#endif
(void)strncpy(ifr.ifr_name, device, sizeof(ifr.ifr_name));
if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0) {
if (errno == EADDRNOTAVAIL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"%s: no IPv4 address assigned", device);
} else {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"SIOCGIFADDR: %s: %s",
device, pcap_strerror(errno));
}
(void)close(fd);
return (-1);
}
sin = (struct sockaddr_in *)&ifr.ifr_addr;
*netp = sin->sin_addr.s_addr;
if (ioctl(fd, SIOCGIFNETMASK, (char *)&ifr) < 0) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"SIOCGIFNETMASK: %s: %s", device, pcap_strerror(errno));
(void)close(fd);
return (-1);
}
(void)close(fd);
*maskp = sin->sin_addr.s_addr;
if (*maskp == 0) {
if (IN_CLASSA(*netp))
*maskp = IN_CLASSA_NET;
else if (IN_CLASSB(*netp))
*maskp = IN_CLASSB_NET;
else if (IN_CLASSC(*netp))
*maskp = IN_CLASSC_NET;
else {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"inet class for 0x%x unknown", *netp);
return (-1);
}
}
*netp &= *maskp;
return (0);
}
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