Get interface names using ioctl rather than /proc, from Nick Fedchik

git-svn-id: svn://busybox.net/trunk/busybox@6224 69ca8d6d-28ef-0310-b511-8ec308f3f277

1 files changed, 68 insertions, 64 deletions

diff --git a/networking/nameif.c b/networking/nameif.c
index 4b2d090ca..a9d422110 100644
--- a/networking/nameif.c
+++ b/networking/nameif.c
@@ -22,21 +22,20 @@
  *
  */
 
+
 #include <sys/syslog.h>
 #include <sys/socket.h>
 #include <sys/ioctl.h>
-
 #include <errno.h>
 #include <getopt.h>
 #include <stdlib.h>
 #include <string.h>
 #include <net/if.h>
 #include <netinet/ether.h>
+#include <linux/sockios.h>
 
 #include "busybox.h"
 
-/* set interface name, from <linux/sockios.h> */
-#define SIOCSIFNAME     0x8923
 /* Octets in one ethernet addr, from <linux/if_ether.h>  */
 #define ETH_ALEN        6
 
@@ -46,12 +45,12 @@
 
 typedef struct mactable_s {
         struct mactable_s *next;
-        struct mactable_s **pprev;
+        struct mactable_s *prev;
         char *ifname;
         struct ether_addr *mac;
 } mactable_t;
 
-static void serror_msg_and_die(const char use_syslog, const char *s, ...)
+static void serror(const char use_syslog, const char *s, ...)
 {
         va_list ap;
 
@@ -67,20 +66,35 @@ static void serror_msg_and_die(const char use_syslog, const char *s, ...)
         }
 
         va_end(ap);
-        
+
         exit(EXIT_FAILURE);
 }
 
+/* Check ascii str_macaddr, convert and copy to *mac */
+struct ether_addr *cc_macaddr(char *str_macaddr, unsigned char use_syslog)
+{
+        struct ether_addr *lmac, *mac;
+
+        lmac = ether_aton(str_macaddr);
+        if (lmac == NULL)
+                serror(use_syslog, "cannot parse MAC %s", str_macaddr);
+        mac = xcalloc(1, ETH_ALEN);
+        memcpy(mac, lmac, ETH_ALEN);
+
+        return mac;
+}
+
 int nameif_main(int argc, char **argv)
 {
         mactable_t *clist = NULL;
         FILE *ifh;
         char *fname = "/etc/mactab";
         char *line;
-        unsigned short linenum = 0;
         unsigned char use_syslog = 0;
         int ctl_sk = -1;
         int opt;
+        int if_index = 1;
+        mactable_t *ch = NULL;
 
         static struct option opts[] = {
                 {"syslog", 0, NULL, 's'},
@@ -101,40 +115,33 @@ int nameif_main(int argc, char **argv)
                 }
         }
 
-        if ((argc - optind) & 1) {
+        if ((argc - optind) & 1)
                 show_usage();
-        }
 
         if (optind < argc) {
                 while (optind < argc) {
-                        struct ether_addr *mac;
-                        mactable_t *ch;
 
-                        if (strlen(argv[optind]) > IF_NAMESIZE) {
-                                serror_msg_and_die(use_syslog, "interface name `%s' too long", argv[optind]);
-                        }
+                        if (strlen(argv[optind]) > IF_NAMESIZE)
+                                serror(use_syslog, "interface name `%s' too long",
+                                           argv[optind]);
                         optind++;
-                        mac = ether_aton(argv[optind]);
-                        if (mac == NULL) {
-                                serror_msg_and_die(use_syslog, "cannot parse MAC %s", argv[optind]);
-                        }
+
                         ch = xcalloc(1, sizeof(mactable_t));
+                        ch->next = NULL;
+                        ch->prev = NULL;
                         ch->ifname = strdup(argv[optind - 1]);
-                        ch->mac = xcalloc(1, ETH_ALEN);
-                        memcpy(ch->mac, mac, ETH_ALEN);
+                        ch->mac = cc_macaddr(argv[optind], use_syslog);
                         optind++;
                         if (clist)
-                                clist->pprev = &ch->next;
+                                clist->prev = ch->next;
                         ch->next = clist;
-                        ch->pprev = &clist;
+                        ch->prev = clist;
                         clist = ch;
                 }
         } else {
                 ifh = xfopen(fname, "r");
 
                 while ((line = get_line_from_file(ifh)) != NULL) {
-                        struct ether_addr *mac;
-                        mactable_t *ch;
                         char *line_ptr;
                         unsigned short name_length;
 
@@ -142,74 +149,71 @@ int nameif_main(int argc, char **argv)
                         if ((line_ptr[0] == '#') || (line_ptr[0] == '\n'))
                                 continue;
                         name_length = strcspn(line_ptr, " \t");
-                        if (name_length > IF_NAMESIZE) {
-                                serror_msg_and_die(use_syslog, "interface name `%s' too long", argv[optind]); 
-                        }
+                        if (name_length > IF_NAMESIZE)
+                                serror(use_syslog, "interface name `%s' too long",
+                                           argv[optind]);
                         ch = xcalloc(1, sizeof(mactable_t));
+                        ch->next = NULL;
+                        ch->prev = NULL;
                         ch->ifname = strndup(line_ptr, name_length);
                         line_ptr += name_length;
                         line_ptr += strspn(line_ptr, " \t");
                         name_length = strspn(line_ptr, "0123456789ABCDEFabcdef:");
                         line_ptr[name_length] = '\0';
-                        mac = ether_aton(line_ptr);
-                        if (mac == NULL) {
-                                serror_msg_and_die(use_syslog,  "cannot parse MAC %s", argv[optind]);
-                        }
-                        ch->mac = xcalloc(1, ETH_ALEN);
-                        memcpy(ch->mac, mac, ETH_ALEN);
+                        ch->mac = cc_macaddr(line_ptr, use_syslog);
                         if (clist)
-                                clist->pprev = &ch->next;
+                                clist->prev = ch;
                         ch->next = clist;
-                        ch->pprev = &clist;
                         clist = ch;
                         free(line);
                 }
                 fclose(ifh);
         }
 
-        ifh = xfopen("/proc/net/dev", "r");
-        while ((line = get_line_from_file(ifh)) != NULL) {
-                char *line_ptr;
-                unsigned short iface_name_length;
+        if ((ctl_sk = socket(PF_INET, SOCK_DGRAM, 0)) == -1)
+                serror(use_syslog, "socket: %s", strerror(errno));
+
+        while (clist) {
                 struct ifreq ifr;
-                mactable_t *ch = NULL;
 
-                linenum++;
-                if (linenum < 3)
-                        continue;
-                line_ptr = line + strspn(line, " \t");
-                if (line_ptr[0] == '\n')
-                        continue;
-                iface_name_length = strcspn(line_ptr, ":");
-                if (ctl_sk < 0)
-                        ctl_sk = socket(PF_INET, SOCK_DGRAM, 0);
-                memset(&ifr, 0, sizeof(struct ifreq));
-                strncpy(ifr.ifr_name, line_ptr, iface_name_length);
-                if (ioctl(ctl_sk, SIOCGIFHWADDR, &ifr) < 0) {
-//                      serror_msg(use_syslog, "cannot read hardware address of %s: %s", ifr.ifr_name, strerror(errno));
+                bzero(&ifr, sizeof(struct ifreq));
+                if_index++;
+                ifr.ifr_ifindex = if_index;
+
+                /* Get ifname by index or die */
+                if (ioctl(ctl_sk, SIOCGIFNAME, &ifr))
+                        break;
+
+                /* Has this device hwaddr? */
+                if (ioctl(ctl_sk, SIOCGIFHWADDR, &ifr))
                         continue;
-                }
+
+                /* Search for mac like in ifr.ifr_hwaddr.sa_data */
                 for (ch = clist; ch; ch = ch->next)
                         if (!memcmp(ch->mac, ifr.ifr_hwaddr.sa_data, ETH_ALEN))
                                 break;
-                if (ch == NULL) {
+
+                /* Nothing found for current ifr.ifr_hwaddr.sa_data */
+                if (ch == NULL)
                         continue;
-                }
 
                 strcpy(ifr.ifr_newname, ch->ifname);
-
-                if (ioctl(ctl_sk, SIOCSIFNAME, &ifr) < 0) {;
-                        serror_msg_and_die(use_syslog, "cannot change name of %s to %s: %s", ifr.ifr_name, ch->ifname, strerror(errno));
+                if (ioctl(ctl_sk, SIOCSIFNAME, &ifr) < 0)
+                        serror(use_syslog, "cannot change ifname %s to %s: %s",
+                                   ifr.ifr_name, ch->ifname, strerror(errno));
+
+                /* Remove list entry of renamed interface */
+                if (ch->prev != NULL) {
+                        (ch->prev)->next = ch->next;
+                } else {
+                        clist = ch->next;
                 }
-                *ch->pprev = ch->next;
+                if (ch->next != NULL)
+                        (ch->next)->prev = ch->prev;
                 free(ch);
-                free(line);
         }
-        fclose(ifh);
 
         while (clist) {
-                mactable_t *ch;
-
                 ch = clist;
                 clist = clist->next;
                 free(ch);