int
add_or_find_if(pcap_if_t **curdev_ret, pcap_if_t **alldevs, const char *name,
u_int flags, const char *description, char *errbuf)
{
pcap_t *p;
pcap_if_t *curdev, *prevdev, *nextdev;
int this_instance;
char open_errbuf[PCAP_ERRBUF_SIZE];
/*
* 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.
*
* Can we open this interface for live capture?
*
* We do this check so that interfaces that are
* supplied by the interface enumeration mechanism
* we're using but that don't support packet capture
* aren't included in the list. Loopback interfaces
* on Solaris are an example of this; we don't just
* omit loopback interfaces on all platforms because
* you *can* capture on loopback interfaces on some
* OSes.
*
* On OS X, we don't do this check if the device
* name begins with "wlt"; at least some versions
* of OS X offer monitor mode capturing by having
* a separate "monitor mode" device for each wireless
* adapter, rather than by implementing the ioctls
* that {Free,Net,Open,DragonFly}BSD provide.
* Opening that device puts the adapter into monitor
* mode, which, at least for some adapters, causes
* them to deassociate from the network with which
* they're associated.
*
* Instead, we try to open the corresponding "en"
* device (so that we don't end up with, for users
* without sufficient privilege to open capture
* devices, a list of adapters that only includes
* the wlt devices).
*/
#ifdef __APPLE__
if (strncmp(name, "wlt", 3) == 0) {
char *en_name;
size_t en_name_len;
/*
* Try to allocate a buffer for the "en"
* device's name.
*/
en_name_len = strlen(name) - 1;
en_name = malloc(en_name_len + 1);
if (en_name == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc: %s", pcap_strerror(errno));
return (-1);
}
strcpy(en_name, "en");
strcat(en_name, name + 3);
p = pcap_open_live(en_name, 68, 0, 0, open_errbuf);
free(en_name);
} else
#endif /* __APPLE */
p = pcap_open_live(name, 68, 0, 0, open_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);
/*
* Yes, we can open 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 = strdup(name);
if (curdev->name == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc: %s", pcap_strerror(errno));
free(curdev);
return (-1);
}
if (description != NULL) {
/*
* We have a description for this interface.
*/
curdev->description = strdup(description);
if (curdev->description == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc: %s", pcap_strerror(errno));
free(curdev->name);
free(curdev);
return (-1);
}
} 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);
}
/*
* Look for a given device in the specified list of devices.
*
* If we find it, return 0 and set *curdev_ret to point to it.
*
* If we don't find it, check whether we can open it:
*
* If that fails with PCAP_ERROR_NO_SUCH_DEVICE or
* PCAP_ERROR_IFACE_NOT_UP, don't attempt to add an entry for
* it, as that probably means it exists but doesn't support
* packet capture.
*
* Otherwise, attempt to add an entry for it, with the specified
* ifnet flags and description, and, if that succeeds, return 0
* and set *curdev_ret to point to the new entry, otherwise
* return PCAP_ERROR and set errbuf to an error message.
*/
int
add_or_find_if(pcap_if_t **curdev_ret, pcap_if_t **alldevs, const char *name,
u_int flags, const char *description, char *errbuf)
{
pcap_t *p;
pcap_if_t *curdev, *prevdev, *nextdev;
u_int this_figure_of_merit, nextdev_figure_of_merit;
char open_errbuf[PCAP_ERRBUF_SIZE];
int ret;
/*
* 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.
*
* Can we open this interface for live capture?
*
* We do this check so that interfaces that are
* supplied by the interface enumeration mechanism
* we're using but that don't support packet capture
* aren't included in the list. Loopback interfaces
* on Solaris are an example of this; we don't just
* omit loopback interfaces on all platforms because
* you *can* capture on loopback interfaces on some
* OSes.
*
* On OS X, we don't do this check if the device
* name begins with "wlt"; at least some versions
* of OS X offer monitor mode capturing by having
* a separate "monitor mode" device for each wireless
* adapter, rather than by implementing the ioctls
* that {Free,Net,Open,DragonFly}BSD provide.
* Opening that device puts the adapter into monitor
* mode, which, at least for some adapters, causes
* them to deassociate from the network with which
* they're associated.
*
* Instead, we try to open the corresponding "en"
* device (so that we don't end up with, for users
* without sufficient privilege to open capture
* devices, a list of adapters that only includes
* the wlt devices).
*/
#ifdef __APPLE__
if (strncmp(name, "wlt", 3) == 0) {
char *en_name;
size_t en_name_len;
/*
* Try to allocate a buffer for the "en"
* device's name.
*/
en_name_len = strlen(name) - 1;
en_name = malloc(en_name_len + 1);
if (en_name == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc: %s", pcap_strerror(errno));
return (-1);
}
strcpy(en_name, "en");
strcat(en_name, name + 3);
p = pcap_create(en_name, open_errbuf);
free(en_name);
} else
#endif /* __APPLE */
p = pcap_create(name, open_errbuf);
if (p == NULL) {
/*
* The attempt to create the pcap_t failed;
* that's probably an indication that we're
* out of memory.
*
* Don't bother including this interface,
* but don't treat it as an error.
*/
*curdev_ret = NULL;
return (0);
}
/* Small snaplen, so we don't try to allocate much memory. */
pcap_set_snaplen(p, 68);
ret = pcap_activate(p);
pcap_close(p);
switch (ret) {
case PCAP_ERROR_NO_SUCH_DEVICE:
case PCAP_ERROR_IFACE_NOT_UP:
/*
* We expect these two errors - they're the
* reason we try to open the device.
*
* PCAP_ERROR_NO_SUCH_DEVICE typically means
* "there's no such device *known to the
* OS's capture mechanism*", so, even though
* it might be a valid network interface, you
* can't capture on it (e.g., the loopback
* device in Solaris up to Solaris 10, or
* the vmnet devices in OS X with VMware
* Fusion). We don't include those devices
* in our list of devices, as there's no
* point in doing so - they're not available
* for capture.
*
* PCAP_ERROR_IFACE_NOT_UP means that the
* OS's capture mechanism doesn't work on
* interfaces not marked as up; some capture
* mechanisms *do* support that, so we no
* longer reject those interfaces out of hand,
* but we *do* want to reject them if they
* can't be opened for capture.
*/
*curdev_ret = NULL;
return (0);
}
/*
* Yes, we can open it, or we can't, for some other
* reason.
*
* If we can open it, we want to offer it for
* capture, as you can capture on it. If we can't,
* we want to offer it for capture, so that, if
* the user tries to capture on it, they'll get
* an error and they'll know why they can't
* capture on it (e.g., insufficient permissions)
* or they'll report it as a problem (and then
* have the error message to provide as information).
*
* 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 = strdup(name);
if (curdev->name == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc: %s", pcap_strerror(errno));
free(curdev);
return (-1);
}
if (description != NULL) {
/*
* We have a description for this interface.
*/
curdev->description = strdup(description);
if (curdev->description == NULL) {
(void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
"malloc: %s", pcap_strerror(errno));
free(curdev->name);
free(curdev);
return (-1);
}
} 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;
if (ISUP(flags))
curdev->flags |= PCAP_IF_UP;
if (ISRUNNING(flags))
curdev->flags |= PCAP_IF_RUNNING;
/*
* Add it to the list, in the appropriate location.
* First, get the "figure of merit" for this
* interface.
*/
this_figure_of_merit = get_figure_of_merit(curdev);
/*
* Now look for the last interface with an figure of merit
* less than or equal to the new interface's figure of
* merit.
*
* 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's figure of merit less
* than the next interface's figure of merit,
* meaning that the new interface is better
* than the next interface?
*/
nextdev_figure_of_merit = get_figure_of_merit(nextdev);
if (this_figure_of_merit < nextdev_figure_of_merit) {
/*
* 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_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);
}
/*
* Return the interface list
*/
int
ifaddrlist(register struct ifaddrlist **ipaddrp, register char *errbuf, size_t l)
{
#ifdef HAVE_GETIFADDRS
struct ifaddrs *ifap, *ifa;
int nipaddr;
struct ifaddrlist *al;
struct ifaddrlist *ifaddrlist;
unsigned int maxif;
struct sockaddr_in *sin;
#if 1
maxif = if_maxindex() * 3; /* 3 is a magic number... */
#else
maxif = 64;
#endif
ifaddrlist = (struct ifaddrlist *)malloc(maxif *
sizeof(struct ifaddrlist));
if (ifaddrlist == NULL)
return -1;
if (getifaddrs(&ifap) != 0)
return -1;
al = ifaddrlist;
nipaddr = 0;
for (ifa = ifap; ifa && nipaddr < maxif; ifa = ifa->ifa_next) {
if (ifa->ifa_addr->sa_family != AF_INET)
continue;
if (((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr ==
htonl(INADDR_ANY))
continue;
if ((ifa->ifa_flags & IFF_UP) == 0)
continue;
#ifdef IFF_LOOPBACK
if ((ifa->ifa_flags & IFF_LOOPBACK) != 0)
continue;
#else
if (strcmp(ifa->ifa_name, "lo0") == 0)
continue;
#endif
sin = (struct sockaddr_in *)ifa->ifa_addr;
al->addr = sin->sin_addr.s_addr;
al->device = strdup(ifa->ifa_name);
++al;
++nipaddr;
}
*ipaddrp = ifaddrlist;
#ifdef HAVE_FREEIFADDRS
freeifaddrs(ifap);
#else
free(ifap);
#endif
return nipaddr;
#else
register int fd, nipaddr;
#ifdef HAVE_SOCKADDR_SA_LEN
register int n;
#endif
register struct ifreq *ifrp, *ifend, *ifnext, *mp;
register struct sockaddr_in *sin;
register struct ifaddrlist *al;
struct ifconf ifc;
struct ifreq *ibuf, ifr;
char device[sizeof(ifr.ifr_name) + 1];
struct ifaddrlist *ifaddrlist;
unsigned int maxif;
#if 1
maxif = if_maxindex() * 3; /* 3 is a magic number... */
#else
maxif = 64;
#endif
ifaddrlist = (struct ifaddrlist *)malloc(maxif *
sizeof(struct ifaddrlist));
if (ifaddrlist == NULL)
return -1;
ibuf = (struct ifreq *)malloc(maxif * sizeof(struct ifreq));
if (ibuf == NULL) {
free(ifaddrlist);
return -1;
}
fd = socket(AF_INET, SOCK_DGRAM, 0);
if (fd < 0) {
(void)snprintf(errbuf, l, "socket: %s", strerror(errno));
free(ifaddrlist);
free(ibuf);
return (-1);
}
ifc.ifc_len = maxif * sizeof(struct ifreq);
ifc.ifc_buf = (caddr_t)ibuf;
if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0 ||
ifc.ifc_len < sizeof(struct ifreq)) {
(void)snprintf(errbuf, l, "SIOCGIFCONF: %s", strerror(errno));
(void)close(fd);
free(ifaddrlist);
free(ibuf);
return (-1);
}
ifrp = ibuf;
ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len);
al = ifaddrlist;
mp = NULL;
nipaddr = 0;
for (; ifrp < ifend; ifrp = ifnext) {
#ifdef HAVE_SOCKADDR_SA_LEN
n = ifrp->ifr_addr.sa_len + sizeof(ifrp->ifr_name);
if (n < sizeof(*ifrp))
ifnext = ifrp + 1;
else
ifnext = (struct ifreq *)((char *)ifrp + n);
if (ifrp->ifr_addr.sa_family != AF_INET)
continue;
#else
ifnext = ifrp + 1;
#endif
if (((struct sockaddr_in *)&ifrp->ifr_addr)->sin_addr.s_addr ==
htonl(INADDR_ANY))
continue;
/*
* Need a template to preserve address info that is
* used below to locate the next entry. (Otherwise,
* SIOCGIFFLAGS stomps over it because the requests
* are returned in a union.)
*/
strncpy(ifr.ifr_name, ifrp->ifr_name, sizeof(ifrp->ifr_name));
if (ioctl(fd, SIOCGIFFLAGS, (char *)&ifr) < 0) {
if (errno == ENXIO)
continue;
(void)snprintf(errbuf, l, "SIOCGIFFLAGS: %.*s: %s",
(int)sizeof(ifr.ifr_name), ifr.ifr_name,
strerror(errno));
(void)close(fd);
free(ifaddrlist);
free(ibuf);
return (-1);
}
/* Must be up and not the loopback */
if ((ifr.ifr_flags & IFF_UP) == 0 || ISLOOPBACK(&ifr))
continue;
(void)strncpy(device, ifr.ifr_name, sizeof(ifr.ifr_name));
device[sizeof(device) - 1] = '\0';
if (ioctl(fd, SIOCGIFADDR, (char *)&ifr) < 0) {
(void)snprintf(errbuf, l, "SIOCGIFADDR: %s: %s",
device, strerror(errno));
(void)close(fd);
free(ifaddrlist);
free(ibuf);
return (-1);
}
sin = (struct sockaddr_in *)&ifr.ifr_addr;
al->addr = sin->sin_addr.s_addr;
al->device = strdup(device);
++al;
++nipaddr;
}
(void)close(fd);
*ipaddrp = ifaddrlist;
free(ibuf);
return (nipaddr);
#endif
}
