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https://github.com/nmap/nmap.git
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Simplify and comment getinterfaces_siocgifconf to make its structure
more clear: We call several different ioctls on each interface and use the results to populate the interface_info array.
This commit is contained in:
david
179
tcpip.cc
179
tcpip.cc
@@ -2912,153 +2912,152 @@ static struct interface_info *getinterfaces_dnet(int *howmany) {
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/* Get a list of interfaces using ioctl(SIOCGIFCONF). */
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static struct interface_info *getinterfaces_siocgifconf(int *howmany) {
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struct interface_info *mydevs;
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int numifaces = 0;
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int ii_capacity = 0;
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int sd;
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struct interface_info *devs;
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int count = 0;
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int capacity = 0;
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struct ifconf ifc;
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struct ifreq *ifr;
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struct ifreq tmpifr;
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int len, rc;
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char *p;
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u8 *buf;
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int bufsz;
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struct sockaddr_in *sin;
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u16 ifflags;
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int sd;
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int len;
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ii_capacity = 16;
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mydevs = (struct interface_info *) safe_zalloc(sizeof(struct interface_info) * ii_capacity);
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capacity = 16;
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devs = (struct interface_info *) safe_zalloc(sizeof(struct interface_info) * capacity);
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/* Dummy socket for ioctl */
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sd = socket(AF_INET, SOCK_DGRAM, 0);
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if (sd < 0) pfatal("socket in %s", __func__);
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bufsz = 20480;
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buf = (u8 *) safe_zalloc(bufsz);
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ifc.ifc_len = bufsz;
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ifc.ifc_buf = (char *) buf;
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if (ioctl(sd, SIOCGIFCONF, &ifc) < 0) {
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if (sd < 0)
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pfatal("socket in %s", __func__);
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ifc.ifc_len = 20480;
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ifc.ifc_buf = (char *) safe_zalloc(ifc.ifc_len);
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/* Returns an array of struct ifreq in ifc.ifc_req, which is a union with
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ifc.ifc_buf. */
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if (ioctl(sd, SIOCGIFCONF, &ifc) < 0)
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fatal("Failed to determine your configured interfaces!\n");
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}
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ifr = (struct ifreq *) buf;
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if (ifc.ifc_len == 0)
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fatal("%s: SIOCGIFCONF claims you have no network interfaces!\n", __func__);
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#if HAVE_SOCKADDR_SA_LEN
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/* len = MAX(sizeof(struct sockaddr), ifr->ifr_addr.sa_len);*/
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len = ifr->ifr_addr.sa_len + sizeof(ifr->ifr_name);
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#else
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len = sizeof(struct ifreq);
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/* len = sizeof(SA); */
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#endif
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ifr = ifc.ifc_req;
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/* Debugging code
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printf("ifnet list length = %d\n",ifc.ifc_len);
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printf("sa_len = %d\n",len);
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hdump((unsigned char *) buf, ifc.ifc_len);
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printf("ifr = %X\n",(unsigned)(*(char **)&ifr));
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printf("Size of struct ifreq: %d\n", sizeof(struct ifreq));
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*/
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for(; ifr && ifr->ifr_name[0] && ((u8 *)ifr) < buf + ifc.ifc_len;
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ifr = (struct ifreq *)(((char *)ifr) + len)) {
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/* debugging code
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printf("ifr_name size = %d\n", sizeof(ifr->ifr_name));
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printf("ifr = %X\n",(unsigned)(*(char **)&ifr));
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*/
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for(ifr = ifc.ifc_req;
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ifr && ifr->ifr_name[0] && (void *) ifr < ifc.ifc_buf + ifc.ifc_len;
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ifr = (struct ifreq *) ((char *) ifr + len)) {
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struct sockaddr_in *sin;
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struct ifreq tmpifr;
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u16 ifflags;
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int rc;
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char *p;
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/* On some platforms (such as FreeBSD), the length of each ifr changes
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based on the sockaddr type used, so we get the next length now */
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based on the sockaddr type used, so we get the next length now. */
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#if HAVE_SOCKADDR_SA_LEN
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len = ifr->ifr_addr.sa_len + sizeof(ifr->ifr_name);
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#endif
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#else
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len = sizeof(struct ifreq);
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#endif
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/* skip any device with no name */
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if (!*((char *)ifr))
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if (ifr->ifr_name[0] == '\0')
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continue;
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/* We currently only handle IPv4 */
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sin = (struct sockaddr_in *) &ifr->ifr_addr;
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if (sin->sin_family != AF_INET)
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continue;
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memcpy(&(mydevs[numifaces].addr), sin, MIN(sizeof(mydevs[numifaces].addr), sizeof(*sin)));
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Strncpy(mydevs[numifaces].devname, ifr->ifr_name, sizeof(mydevs[numifaces].devname));
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/* devname isn't allowed to have alias qualification */
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if ((p = strchr(mydevs[numifaces].devname, ':')))
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*p = '\0';
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Strncpy(mydevs[numifaces].devfullname, ifr->ifr_name, sizeof(mydevs[numifaces].devfullname));
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/* Make room for this new interface if necessary. */
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if (count > capacity) {
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capacity <<= 2;
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devs = (struct interface_info *) safe_realloc(devs, sizeof(struct interface_info) * capacity);
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}
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/* We know the address, put it in the array. */
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memcpy(&(devs[count].addr), sin, MIN(sizeof(devs[count].addr), sizeof(*sin)));
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Strncpy(devs[count].devname, ifr->ifr_name, sizeof(devs[count].devname));
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Strncpy(devs[count].devfullname, ifr->ifr_name, sizeof(devs[count].devfullname));
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/* devname isn't allowed to have alias qualification */
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p = strchr(devs[count].devname, ':');
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if (p != NULL)
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*p = '\0';
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/* Use tmpifr for further ioctl requests. We're going to make a bunch of
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ioctl calls to learn about the interface and set fields in devs[count].
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The Linux netdevice(7) man page says that you only have to set ifr_name
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before making the ioctl, but perhaps other platforms need ifr_addr to be
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set too. ifr_name will persist but ifr_addr is in a union with the ioctl
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return value, so it has to be reset before every call. The general
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pattern is memcpy, then ioctl. */
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Strncpy(tmpifr.ifr_name, ifr->ifr_name, sizeof(tmpifr.ifr_name));
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memcpy(&(tmpifr.ifr_addr), sin, MIN(sizeof(tmpifr.ifr_addr), sizeof(*sin)));
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/* Look up the netmask. Note setting of ifr_addr. */
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memcpy(&tmpifr.ifr_addr, sin, MIN(sizeof(tmpifr.ifr_addr), sizeof(*sin)));
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rc = ioctl(sd, SIOCGIFNETMASK, &tmpifr);
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if (rc < 0 && errno != EADDRNOTAVAIL)
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pfatal("Failed to determine the netmask of %s!", tmpifr.ifr_name);
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else if (rc < 0)
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mydevs[numifaces].netmask_bits = 32;
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devs[count].netmask_bits = 32;
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else {
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/* We would use ifr_netmask, but that's only on Linux, so use ifr_addr
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which shares the same memory space in a union. */
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addr_stob(&(tmpifr.ifr_addr), &mydevs[numifaces].netmask_bits);
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addr_stob(&(tmpifr.ifr_addr), &devs[count].netmask_bits);
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}
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// printf("ifr name=%s addr=%s, mask=%X\n", mydevs[numifaces].name, inet_ntoa(mydevs[numifaces].addr), mydevs[numifaces].netmask.s_addr);
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/* Now we need to determine the device type ... this technique
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is kinda iffy ... may not be portable. */
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/* First we get the flags */
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Strncpy(tmpifr.ifr_name, ifr->ifr_name, sizeof(tmpifr.ifr_name));
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memcpy(&(tmpifr.ifr_addr), sin, MIN(sizeof(tmpifr.ifr_addr), sizeof(*sin)));
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/* Now we need to determine the device type ... this technique is kinda iffy
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... may not be portable. */
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/* Get the flags. */
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memcpy(&tmpifr.ifr_addr, sin, MIN(sizeof(tmpifr.ifr_addr), sizeof(*sin)));
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rc = ioctl(sd, SIOCGIFFLAGS, &tmpifr);
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if (rc < 0) fatal("Failed to get IF Flags for device %s", ifr->ifr_name);
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if (rc < 0)
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pfatal("Failed to get IF Flags for device %s", ifr->ifr_name);
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ifflags = tmpifr.ifr_flags;
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if (ifflags & IFF_LOOPBACK)
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mydevs[numifaces].device_type = devt_loopback;
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else if (ifflags & IFF_BROADCAST) {
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mydevs[numifaces].device_type = devt_ethernet;
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/* Get the MAC Address ... */
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if (ifflags & IFF_LOOPBACK) {
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devs[count].device_type = devt_loopback;
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} else if (ifflags & IFF_BROADCAST) {
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devs[count].device_type = devt_ethernet;
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/* If the device type is ethernet, get the MAC address. */
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#ifdef SIOCGIFHWADDR
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Strncpy(tmpifr.ifr_name, mydevs[numifaces].devname, sizeof(tmpifr.ifr_name));
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memcpy(&(tmpifr.ifr_addr), sin, MIN(sizeof(tmpifr.ifr_addr), MIN(sizeof(tmpifr.ifr_addr), sizeof(*sin))));
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memcpy(&tmpifr.ifr_addr, sin, MIN(sizeof(tmpifr.ifr_addr), sizeof(*sin)));
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rc = ioctl(sd, SIOCGIFHWADDR, &tmpifr);
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if (rc < 0 && errno != EADDRNOTAVAIL)
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pfatal("Failed to determine the MAC address of %s!", tmpifr.ifr_name);
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else if (rc >= 0)
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memcpy(mydevs[numifaces].mac, &tmpifr.ifr_addr.sa_data, 6);
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memcpy(devs[count].mac, &tmpifr.ifr_addr.sa_data, 6);
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#else
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/* Let's just let libdnet handle it ... */
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eth_t *ethsd = eth_open_cached(mydevs[numifaces].devname);
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eth_t *ethsd = eth_open_cached(devs[count].devname);
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eth_addr_t ethaddr;
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if (!ethsd) {
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error("Warning: Unable to open interface %s -- skipping it.", mydevs[numifaces].devname);
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error("Warning: Unable to open interface %s -- skipping it.", devs[count].devname);
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continue;
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}
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if (eth_get(ethsd, ðaddr) != 0)
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fatal("%s: Failed to obtain MAC address for ethernet interface (%s)",
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__func__, mydevs[numifaces].devname);
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memcpy(mydevs[numifaces].mac, ethaddr.data, 6);
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__func__, devs[count].devname);
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memcpy(devs[count].mac, ethaddr.data, 6);
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#endif /*SIOCGIFHWADDR*/
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} else if (ifflags & IFF_POINTOPOINT) {
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devs[count].device_type = devt_p2p;
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} else {
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devs[count].device_type = devt_other;
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}
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else if (ifflags & IFF_POINTOPOINT)
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mydevs[numifaces].device_type = devt_p2p;
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else mydevs[numifaces].device_type = devt_other;
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if (ifflags & IFF_UP)
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mydevs[numifaces].device_up = true;
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else mydevs[numifaces].device_up = false;
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numifaces++;
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if (numifaces == ii_capacity) {
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ii_capacity <<= 2;
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mydevs = (struct interface_info *) safe_realloc(mydevs, sizeof(struct interface_info) * ii_capacity);
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}
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mydevs[numifaces].devname[0] = mydevs[numifaces].devfullname[0] = '\0';
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devs[count].device_up = true;
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else
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devs[count].device_up = false;
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/* All done with this interface. Increase the count. */
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count++;
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}
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free(buf);
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free(ifc.ifc_buf);
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close(sd);
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*howmany = numifaces;
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return mydevs;
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*howmany = count;
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return devs;
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}
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#endif
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