From b90a502652f44672263353d347fd6adc8110e8ec Mon Sep 17 00:00:00 2001
From: Mathieu Anquetin <mathieu.anquetin@groupe-cahors.com>
Date: Fri, 27 Oct 2023 14:46:34 +0200
Subject: [PATCH] ip: improve 'ip link set' parsing

Some utilities expect that the order of parameters does not matter since
it is the behavior of iproute2 utility. So, fix parsing to provide the
same behavior for toybox.

Signed-off-by: Mathieu Anquetin <mathieu.anquetin@groupe-cahors.com>
---
 toys/pending/ip.c | 96 ++++++++++++++++++++++++++++++++++-------------
 1 file changed, 70 insertions(+), 26 deletions(-)

diff --git a/toys/pending/ip.c b/toys/pending/ip.c
index 6676ffe9..754b7728 100644
--- a/toys/pending/ip.c
+++ b/toys/pending/ip.c
@@ -684,19 +684,16 @@ static int link_set(char **argv)
 {
   struct arglist cmd_objectlist[] = {{"up", 0}, {"down", 1}, {"arp", 2}, 
     {"multicast", 3}, {"dynamic", 4}, {"name", 5}, {"txqueuelen", 6}, 
-    {"mtu", 7},{"address", 8}, {"broadcast", 9}, {NULL,-1}};
+    {"mtu", 7},{"address", 8}, {"broadcast", 9}, {"dev", 10}, {NULL,-1}};
   int case_flags[] = {IFF_NOARP,IFF_MULTICAST,IFF_DYNAMIC};
   struct ifreq req;
   int idx, flags = 0, masks = 0xffff, fd;
+  char *dev = NULL, *newdev = NULL, *newaddr = NULL, *newbrd = NULL;
+  int mtu = -1, txqlen = -1;
 
-  memset(&req, 0, sizeof(req));
-  if (!*argv) error_exit("\"dev\" missing");
-  xstrncpy(req.ifr_name, *argv, IF_NAMESIZE);
-  fd = xsocket(AF_INET, SOCK_DGRAM, 0);
-  xioctl(fd, SIOCGIFINDEX, &req);
-  for (++argv; *argv;) {
-    if ((idx = substring_to_idx(*argv++, cmd_objectlist)) == -1) help_exit(0);
-    switch(idx) {
+  int i = 0;
+  while (*argv) {
+    switch(idx = substring_to_idx(*argv, cmd_objectlist)) {
       case 0:
         flags |= IFF_UP; break;
       case 1:
@@ -704,6 +701,7 @@ static int link_set(char **argv)
       case 2:
       case 3:
       case 4:
+        ++argv;
         if (!*argv) help_exit(0);
         else if (!strcmp(*argv, "on")) {
           if (idx == 2) {
@@ -716,36 +714,82 @@ static int link_set(char **argv)
             flags |= case_flags[idx-2];
           } else masks &= ~case_flags[idx-2];
         } else help_exit(0);
-        ++argv;
         break;
       case 5:
-        xstrncpy(req.ifr_ifru.ifru_newname, *argv, IF_NAMESIZE);
-        xioctl(fd, SIOCSIFNAME, &req);
-        xstrncpy(req.ifr_name, *argv++, IF_NAMESIZE);
-        xioctl(fd, SIOCGIFINDEX, &req);
+        ++argv;
+        if (!*argv) error_exit("Incomplete Command line");
+        newdev = *argv;
         break;
       case 6:
-        req.ifr_ifru.ifru_ivalue = atolx(*argv++);
-        xioctl(fd, SIOCSIFTXQLEN, &req);
+        ++argv;
+        if (!*argv) error_exit("Incomplete Command line");
+        txqlen = atolx(*argv);
         break;
       case 7:
-        req.ifr_ifru.ifru_mtu = atolx(*argv++);
-        xioctl(fd, SIOCSIFMTU, &req);
+        ++argv;
+        if (!*argv) error_exit("Incomplete Command line");
+        mtu = atolx(*argv);
         break;
       case 8:
-        xioctl(fd, SIOCGIFHWADDR, &req);
-        fill_hwaddr(*argv++, IF_NAMESIZE, 
-            (unsigned char *)(req.ifr_hwaddr.sa_data));
-        xioctl(fd, SIOCSIFHWADDR, &req);
+        ++argv;
+        if (!*argv) error_exit("Incomplete Command line");
+        newaddr = *argv;
         break;
       case 9:
-        xioctl(fd, SIOCGIFHWADDR, &req);
-        fill_hwaddr(*argv++, IF_NAMESIZE,
-            (unsigned char *)(req.ifr_hwaddr.sa_data));
-        xioctl(fd, SIOCSIFHWBROADCAST, &req);
+        ++argv;
+        if (!*argv) error_exit("Incomplete Command line");
+        newbrd = *argv;
+        break;
+      case 10:
+        ++argv;
+        if (!*argv) error_exit("Incomplete Command line");
+
+      default:
+        if (dev)
+          error_exit("Either \"dev\" is duplicate or %s is garbage",
+              *argv);
+        dev = *argv;
         break;
     }
+    ++argv;
+  }
+
+  memset(&req, 0, sizeof(req));
+  if (!dev) error_exit("\"dev\" missing");
+  xstrncpy(req.ifr_name, dev, IF_NAMESIZE);
+  fd = xsocket(AF_INET, SOCK_DGRAM, 0);
+
+  if (newdev) {
+    xstrncpy(req.ifr_ifru.ifru_newname, newdev, IF_NAMESIZE);
+    xioctl(fd, SIOCSIFNAME, &req);
+    xstrncpy(req.ifr_name, newdev, IF_NAMESIZE);
+  }
+  xioctl(fd, SIOCGIFINDEX, &req);
+
+  if (txqlen != -1) {
+    req.ifr_ifru.ifru_ivalue = txqlen;
+    xioctl(fd, SIOCSIFTXQLEN, &req);
   }
+
+  if (mtu != -1) {
+    req.ifr_ifru.ifru_mtu = mtu;
+    xioctl(fd, SIOCSIFMTU, &req);
+  }
+
+  if (newaddr) {
+    xioctl(fd, SIOCGIFHWADDR, &req);
+    fill_hwaddr(newaddr, IF_NAMESIZE,
+        (unsigned char *)(req.ifr_hwaddr.sa_data));
+    xioctl(fd, SIOCSIFHWADDR, &req);
+  }
+
+  if (newbrd) {
+    xioctl(fd, SIOCGIFHWADDR, &req);
+    fill_hwaddr(newbrd, IF_NAMESIZE,
+        (unsigned char *)(req.ifr_hwaddr.sa_data));
+    xioctl(fd, SIOCSIFHWBROADCAST, &req);
+  }
+
   xioctl(fd, SIOCGIFFLAGS, &req);
   req.ifr_ifru.ifru_flags |= flags;
   req.ifr_ifru.ifru_flags &= masks;
-- 
2.39.2