mountd: Convert colons in IPv6 presentation addresses tosemicolons

The /var/lib/nfs/rmtab file delineates fields in each of its lines
with a ":".  The first field contains the IP address of a client, in
presentation format.  IPv6 presentation format addresses contain
colons, which screws up the field delineation of rmtab.

Use a simple simple scheme to convert the colons in incoming client
names to some other character, and then convert them back when the
rmtab file is read.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Steve Dickson <steved@redhat.com>

diff --git a/support/nfs/rmtab.c b/support/nfs/rmtab.c
index a28abf343898791b415336d36ef67c4977063d5f..ca789a32c6a8599b07f0c74c0aa531a0b58a661d 100644 (file)
--- a/support/nfs/rmtab.c
+++ b/support/nfs/rmtab.c
@@ -19,6 +19,18 @@
 #include <signal.h>
 #include "nfslib.h"
 
+/*
+ * Colons in incoming IPv6 presentation addresses have to
+ * replaced with another character, since rmtab already
+ * uses colons to delineate fields.
+ *
+ * Use a printable character, but one that would never be
+ * found in a presentation address or domain name
+ */
+#define IPV6_COLON     ';'
+
+#define LINELEN                (2048)
+
 static FILE    *rmfp = NULL;
 
 int
@@ -56,7 +68,8 @@ struct rmtabent *
 fgetrmtabent(FILE *fp, int log, long *pos)
 {
        static struct rmtabent  re;
-       char    buf[2048], *count, *host, *path;
+       char            *count, *host, *path, *c;
+       static char     buf[LINELEN];
 
        errno = 0;
        if (!fp)
@@ -84,10 +97,16 @@ fgetrmtabent(FILE *fp, int log, long *pos)
                else
                        re.r_count = 1;
        } while (0);
+
        strncpy(re.r_client, host, sizeof (re.r_client) - 1);
        re.r_client[sizeof (re.r_client) - 1] = '\0';
+       for (c = re.r_client; *c != '\0'; c++)
+               if (*c == IPV6_COLON)
+                       *c = ':';
+
        strncpy(re.r_path, path, sizeof (re.r_path) - 1);
        re.r_path[sizeof (re.r_path) - 1] = '\0';
+
        return &re;
 }
 
@@ -100,10 +119,27 @@ putrmtabent(struct rmtabent *rep, long *pos)
 void
 fputrmtabent(FILE *fp, struct rmtabent *rep, long *pos)
 {
+       static char     buf[LINELEN];
+       char            *c;
+
        if (!fp || (pos && fseek (fp, *pos, SEEK_SET) != 0))
                return;
-       fprintf(fp, "%s:%s:0x%.8x\n", rep->r_client, rep->r_path,
-               rep->r_count);
+
+       /*
+        * To avoid confusing the token parser in fgetrmtabent(),
+        * convert colons in incoming IPv6 presentation addresses
+        * to semicolons.
+        */
+       if (strlen(rep->r_client) > sizeof(buf)) {
+               xlog(L_ERROR, "client name too large");
+               return;
+       }
+       strncpy(buf, rep->r_client, sizeof(buf));
+       for (c = buf; *c != '\0'; c++)
+               if (*c == ':')
+                       *c = IPV6_COLON;
+
+       (void)fprintf(fp, "%s:%s:0x%.8x\n", buf, rep->r_path, rep->r_count);
 }
 
 void