+ handle->md.stat.ps_recv += kstats.tp_packets;
+ handle->md.stat.ps_drop += kstats.tp_drops;
+ *stats = handle->md.stat;
+ return 0;
+ }
+ else
+ {
+ /*
+ * If the error was EOPNOTSUPP, fall through, so that
+ * if you build the library on a system with
+ * "struct tpacket_stats" and run it on a system
+ * that doesn't, it works as it does if the library
+ * is built on a system without "struct tpacket_stats".
+ */
+ if (errno != EOPNOTSUPP) {
+ snprintf(handle->errbuf, PCAP_ERRBUF_SIZE,
+ "pcap_stats: %s", pcap_strerror(errno));
+ return -1;
+ }
+ }
+#endif
+ /*
+ * On systems where the PACKET_STATISTICS "getsockopt()" argument
+ * is not supported on PF_PACKET sockets:
+ *
+ * "ps_recv" counts only packets that *passed* the filter,
+ * not packets that didn't pass the filter. It does not
+ * count packets dropped because we ran out of buffer
+ * space.
+ *
+ * "ps_drop" is not supported.
+ *
+ * "ps_ifdrop" is supported. It will return the number
+ * of drops the interface reports in /proc/net/dev,
+ * if that is available.
+ *
+ * "ps_recv" doesn't include packets not yet read from
+ * the kernel by libpcap.
+ *
+ * We maintain the count of packets processed by libpcap in
+ * "md.packets_read", for reasons described in the comment
+ * at the end of pcap_read_packet(). We have no idea how many
+ * packets were dropped by the kernel buffers -- but we know
+ * how many the interface dropped, so we can return that.
+ */
+
+ stats->ps_recv = handle->md.packets_read;
+ stats->ps_drop = 0;
+ stats->ps_ifdrop = handle->md.stat.ps_ifdrop;
+ return 0;
+}
+
+/*
+ * Get from "/sys/class/net" 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 "/sys/class/net"; we just leave
+ * the list of interfaces as is, and return 0, so that we can try
+ * scanning /proc/net/dev.
+ */
+static int
+scan_sys_class_net(pcap_if_t **devlistp, char *errbuf)
+{
+ DIR *sys_class_net_d;
+ int fd;
+ struct dirent *ent;
+ char subsystem_path[PATH_MAX+1];
+ struct stat statb;
+ char *p;
+ char name[512]; /* XXX - pick a size */
+ char *q, *saveq;
+ struct ifreq ifrflags;
+ int ret = 1;
+
+ sys_class_net_d = opendir("/sys/class/net");
+ if (sys_class_net_d == NULL) {
+ /*
+ * Don't fail if it doesn't exist at all.
+ */
+ if (errno == ENOENT)
+ return (0);
+
+ /*
+ * Fail if we got some other error.
+ */
+ (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
+ "Can't open /sys/class/net: %s", pcap_strerror(errno));
+ return (-1);
+ }
+
+ /*
+ * Create a socket from which to fetch interface information.
+ */
+ fd = socket(AF_INET, SOCK_DGRAM, 0);
+ if (fd < 0) {
+ (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
+ "socket: %s", pcap_strerror(errno));
+ (void)closedir(sys_class_net_d);
+ return (-1);
+ }
+
+ for (;;) {
+ errno = 0;
+ ent = readdir(sys_class_net_d);
+ if (ent == NULL) {
+ /*
+ * Error or EOF; if errno != 0, it's an error.
+ */
+ break;
+ }
+
+ /*
+ * Ignore "." and "..".
+ */
+ if (strcmp(ent->d_name, ".") == 0 ||
+ strcmp(ent->d_name, "..") == 0)
+ continue;
+
+ /*
+ * Ignore plain files; they do not have subdirectories
+ * and thus have no attributes.
+ */
+ if (ent->d_type == DT_REG)
+ continue;
+
+ /*
+ * Is there an "ifindex" file under that name?
+ * (We don't care whether it's a directory or
+ * a symlink; older kernels have directories
+ * for devices, newer kernels have symlinks to
+ * directories.)
+ */
+ snprintf(subsystem_path, sizeof subsystem_path,
+ "/sys/class/net/%s/ifindex", ent->d_name);
+ if (lstat(subsystem_path, &statb) != 0) {
+ /*
+ * Stat failed. Either there was an error
+ * other than ENOENT, and we don't know if
+ * this is an interface, or it's ENOENT,
+ * and either some part of "/sys/class/net/{if}"
+ * disappeared, in which case it probably means
+ * the interface disappeared, or there's no
+ * "ifindex" file, which means it's not a
+ * network interface.
+ */
+ continue;
+ }
+
+ /*
+ * Get the interface name.
+ */
+ p = &ent->d_name[0];
+ q = &name[0];
+ while (*p != '\0' && isascii(*p) && !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 (isascii(*p) && 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 || errno == ENODEV)
+ 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 directory?
+ */
+ if (errno != 0) {
+ (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
+ "Error reading /sys/class/net: %s",
+ pcap_strerror(errno));
+ ret = -1;
+ }
+ }
+
+ (void)close(fd);
+ (void)closedir(sys_class_net_d);
+ return (ret);
+}
+
+/*
+ * 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.
+ *
+ * See comments from scan_sys_class_net().
+ */
+static int
+scan_proc_net_dev(pcap_if_t **devlistp, char *errbuf)
+{
+ FILE *proc_net_f;
+ int fd;
+ char linebuf[512];
+ int linenum;
+ 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) {
+ /*
+ * Don't fail if it doesn't exist at all.
+ */
+ if (errno == ENOENT)
+ return (0);
+
+ /*
+ * Fail if we got some other error.
+ */
+ (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
+ "Can't open /proc/net/dev: %s", pcap_strerror(errno));
+ return (-1);
+ }
+
+ /*
+ * Create a socket from which to fetch interface information.
+ */
+ fd = socket(AF_INET, SOCK_DGRAM, 0);
+ if (fd < 0) {
+ (void)snprintf(errbuf, PCAP_ERRBUF_SIZE,
+ "socket: %s", pcap_strerror(errno));
+ (void)fclose(proc_net_f);
+ return (-1);
+ }
+
+ 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' && isascii(*p) && isspace(*p))
+ p++;
+ if (*p == '\0' || *p == '\n')
+ continue; /* blank line */
+
+ /*
+ * Get the interface name.
+ */
+ q = &name[0];
+ while (*p != '\0' && isascii(*p) && !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 (isascii(*p) && 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;
+ }
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