mount.nfs: Use dynamically allocated character buffers

Replace the use of static character arrays with buffers allocated via
xstrdup() in stropts.c.

I added a couple of extra length checks; not sure if these are really
necessary.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Neil Brown <neilb@suse.de>

diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c
index cc13325750aa1eb22e542c6c7911a8333e770838..bd6e60dd3d51e2eaeaeac181043b8a2c577c0c2f 100644 (file)
--- a/utils/mount/stropts.c
+++ b/utils/mount/stropts.c
@@ -52,6 +52,14 @@
 #define NFS_PORT 2049
 #endif
 
+#ifndef NFS_MAXHOSTNAME
+#define NFS_MAXHOSTNAME                (255)
+#endif
+
+#ifndef NFS_MAXPATHNAME
+#define NFS_MAXPATHNAME                (1024)
+#endif
+
 extern int nfs_mount_data_version;
 extern char *progname;
 extern int verbose;
@@ -61,26 +69,55 @@ static int bg_opt = 0;
 static int addr_opt = 0;
 static int ca_opt = 0;
 
-static int parse_devname(char *hostdir, char **hostname, char **dirname)
+static int parse_devname(const char *spec, char **hostname)
 {
-       char *s;
+       int ret = 0;
+       char *dev, *pathname, *s;
+
+       dev = xstrdup(spec);
 
-       if (!(s = strchr(hostdir, ':'))) {
-               nfs_error(_("%s: directory to mount not in host:dir format"),
+       if (!(pathname = strchr(dev, ':'))) {
+               nfs_error(_("%s: remote share not in 'host:dir' format"),
                                progname);
-               return -1;
+               goto out;
        }
-       *hostname = hostdir;
-       *dirname = s + 1;
-       *s = '\0';
-       /* Ignore all but first hostname in replicated mounts
-          until they can be fully supported. (mack@sgi.com) */
-       if ((s = strchr(hostdir, ','))) {
+       *pathname = '\0';
+       pathname++;
+
+       /*
+        * We don't need a copy of the pathname, but let's
+        * sanity check it anyway.
+        */
+       if (strlen(pathname) > NFS_MAXPATHNAME) {
+               nfs_error(_("%s: export pathname is too long"),
+                               progname);
+               goto out;
+       }
+
+       /*
+        * Ignore all but first hostname in replicated mounts
+        * until they can be fully supported. (mack@sgi.com)
+        */
+       if ((s = strchr(dev, ','))) {
                *s = '\0';
                nfs_error(_("%s: warning: multiple hostnames not supported"),
                                progname);
+               nfs_error(_("%s: ignoring hostnames that follow the first one"),
+                               progname);
        }
-       return 0;
+       *hostname = xstrdup(dev);
+       if (strlen(*hostname) > NFS_MAXHOSTNAME) {
+               nfs_error(_("%s: server hostname is too long"),
+                               progname);
+               free(*hostname);
+               goto out;
+       }
+
+       ret = 1;
+
+out:
+       free(dev);
+       return ret;
 }
 
 static int fill_ipv4_sockaddr(const char *hostname, struct sockaddr_in *addr)
@@ -161,33 +198,27 @@ static void extract_interesting_options(char *opts)
 }
 
 /*
- * Append the 'addr=' option to the options string.
+ * Append the 'addr=' option to the options string.  The server
+ * address is added to /etc/mtab for use when unmounting.
  *
  * Returns 1 if 'addr=' option created successfully;
  * otherwise zero.
  */
 static int append_addr_opt(const char *spec, char **extra_opts)
 {
-       static char hostdir[1024], new_opts[1024];
-       char *hostname, *dirname, *s, *old_opts;
+       static char new_opts[1024];
+       char *hostname, *s, *old_opts;
        struct sockaddr_in addr;
+       int err;
 
-       if (strlen(spec) >= sizeof(hostdir)) {
-               nfs_error(_("%s: excessively long host:dir argument\n"),
-                               progname);
+       if (!parse_devname(spec, &hostname))
                return 0;
-       }
-       strcpy(hostdir, spec);
-       if (parse_devname(hostdir, &hostname, &dirname)) {
-               nfs_error(_("%s: parsing host:dir argument failed\n"),
-                               progname);
-               return 0;
-       }
 
-       if (!fill_ipv4_sockaddr(hostname, &addr))
+       err = fill_ipv4_sockaddr(hostname, &addr);
+       free(hostname);
+       if (!err)
                return 0;
 
-       /* add IP address to mtab options for use when unmounting */
        s = inet_ntoa(addr.sin_addr);
        old_opts = *extra_opts;
        if (!old_opts)