CIFS: Make cifs_convert_address() take a const src pointer and a length

Make cifs_convert_address() take a const src pointer and a length so that all
the strlen() calls in their can be cut out and to make it unnecessary to modify
the src string.

Also return the data length from dns_resolve_server_name_to_ip() so that a
strlen() can be cut out of cifs_compose_mount_options() too.

Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 24 insertions, 21 deletions

diff --git a/fs/cifs/netmisc.c b/fs/cifs/netmisc.c
index c6721ee26dbc..f97851119e6c 100644
--- a/fs/cifs/netmisc.c
+++ b/fs/cifs/netmisc.c
@@ -140,17 +140,18 @@ static const struct smb_to_posix_error mapping_table_ERRHRD[] = {
  * Returns 0 on failure.
  */
 static int
-cifs_inet_pton(const int address_family, const char *cp, void *dst)
+cifs_inet_pton(const int address_family, const char *cp, int len, void *dst)
 {
         int ret = 0;
 
         /* calculate length by finding first slash or NULL */
         if (address_family == AF_INET)
-                ret = in4_pton(cp, -1 /* len */, dst, '\\', NULL);
+                ret = in4_pton(cp, len, dst, '\\', NULL);
         else if (address_family == AF_INET6)
-                ret = in6_pton(cp, -1 /* len */, dst , '\\', NULL);
+                ret = in6_pton(cp, len, dst , '\\', NULL);
 
-        cFYI(DBG2, "address conversion returned %d for %s", ret, cp);
+        cFYI(DBG2, "address conversion returned %d for %*.*s",
+             ret, len, len, cp);
         if (ret > 0)
                 ret = 1;
         return ret;
@@ -165,37 +166,39 @@ cifs_inet_pton(const int address_family, const char *cp, void *dst)
  * Returns 0 on failure.
  */
 int
-cifs_convert_address(struct sockaddr *dst, char *src)
+cifs_convert_address(struct sockaddr *dst, const char *src, int len)
 {
-        int rc;
-        char *pct, *endp;
+        int rc, alen, slen;
+        const char *pct;
+        char *endp, scope_id[13];
         struct sockaddr_in *s4 = (struct sockaddr_in *) dst;
         struct sockaddr_in6 *s6 = (struct sockaddr_in6 *) dst;
 
         /* IPv4 address */
-        if (cifs_inet_pton(AF_INET, src, &s4->sin_addr.s_addr)) {
+        if (cifs_inet_pton(AF_INET, src, len, &s4->sin_addr.s_addr)) {
                 s4->sin_family = AF_INET;
                 return 1;
         }
 
-        /* temporarily terminate string */
-        pct = strchr(src, '%');
-        if (pct)
-                *pct = '\0';
-
-        rc = cifs_inet_pton(AF_INET6, src, &s6->sin6_addr.s6_addr);
-
-        /* repair temp termination (if any) and make pct point to scopeid */
-        if (pct)
-                *pct++ = '%';
+        /* attempt to exclude the scope ID from the address part */
+        pct = memchr(src, '%', len);
+        alen = pct ? pct - src : len;
 
+        rc = cifs_inet_pton(AF_INET6, src, alen, &s6->sin6_addr.s6_addr);
         if (!rc)
                 return rc;
 
         s6->sin6_family = AF_INET6;
         if (pct) {
+                /* grab the scope ID */
+                slen = len - (alen + 1);
+                if (slen <= 0 || slen > 12)
+                        return 0;
+                memcpy(scope_id, pct + 1, slen);
+                scope_id[slen] = '\0';
+
                 s6->sin6_scope_id = (u32) simple_strtoul(pct, &endp, 0);
-                if (!*pct || *endp)
+                if (endp != scope_id + slen)
                         return 0;
         }
 
@@ -203,10 +206,10 @@ cifs_convert_address(struct sockaddr *dst, char *src)
 }
 
 int
-cifs_fill_sockaddr(struct sockaddr *dst, char *src,
+cifs_fill_sockaddr(struct sockaddr *dst, const char *src, int len,
                    const unsigned short int port)
 {
-        if (!cifs_convert_address(dst, src))
+        if (!cifs_convert_address(dst, src, len))
                 return 0;
 
         switch (dst->sa_family) {