route: fix bogus read error when route table is empty

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/networking/route.c b/networking/route.c
index d82b0132ad4a88d05bb8e13fc26063368e06dbcf..65c2fb7c85bbaf87cc2cd4ac66c62f93c586dee8 100644 (file)
--- a/networking/route.c
+++ b/networking/route.c
@@ -494,6 +494,7 @@ void FAST_FUNC bb_displayroutes(int noresolve, int netstatfmt)
 {
        char devname[64], flags[16], *sdest, *sgw;
        unsigned long d, g, m;
+       int r;
        int flgs, ref, use, metric, mtu, win, ir;
        struct sockaddr_in s_addr;
        struct in_addr mask;
@@ -504,20 +505,24 @@ void FAST_FUNC bb_displayroutes(int noresolve, int netstatfmt)
                "Destination     Gateway         Genmask         Flags %s Iface\n",
                        netstatfmt ? "  MSS Window  irtt" : "Metric Ref    Use");
 
-       if (fscanf(fp, "%*[^\n]\n") < 0) { /* Skip the first line. */
-               goto ERROR;                /* Empty or missing line, or read error. */
+       /* Skip the first line. */
+       r = fscanf(fp, "%*[^\n]\n");
+       if (r < 0) {
+               /* Empty line, read error, or EOF. Yes, if routing table
+                * is completely empty, /proc/net/route has no header.
+                */
+               goto ERROR;
        }
        while (1) {
-               int r;
                r = fscanf(fp, "%63s%lx%lx%X%d%d%d%lx%d%d%d\n",
                                devname, &d, &g, &flgs, &ref, &use, &metric, &m,
                                &mtu, &win, &ir);
                if (r != 11) {
+ ERROR:
                        if ((r < 0) && feof(fp)) { /* EOF with no (nonspace) chars read. */
                                break;
                        }
- ERROR:
-                       bb_error_msg_and_die("fscanf");
+                       bb_perror_msg_and_die(bb_msg_read_error);
                }
 
                if (!(flgs & RTF_UP)) { /* Skip interfaces that are down. */
@@ -583,7 +588,7 @@ static void INET6_displayroutes(void)
                                break;
                        }
  ERROR:
-                       bb_error_msg_and_die("fscanf");
+                       bb_perror_msg_and_die(bb_msg_read_error);
                }
 
                /* Do the addr6x shift-and-insert changes to ':'-delimit addresses.