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>

5 files changed, 38 insertions, 37 deletions

diff --git a/fs/cifs/cifs_dfs_ref.c b/fs/cifs/cifs_dfs_ref.c
index dc1ed50ea06e..d6ced7aa23cf 100644
--- a/fs/cifs/cifs_dfs_ref.c
+++ b/fs/cifs/cifs_dfs_ref.c
@@ -141,7 +141,7 @@ char *cifs_compose_mount_options(const char *sb_mountdata,
         }
 
         rc = dns_resolve_server_name_to_ip(*devname, &srvIP);
-        if (rc != 0) {
+        if (rc < 0) {
                 cERROR(1, "%s: Failed to resolve server part of %s to IP: %d",
                           __func__, *devname, rc);
                 goto compose_mount_options_err;
@@ -150,8 +150,7 @@ char *cifs_compose_mount_options(const char *sb_mountdata,
          * assuming that we have 'unc=' and 'ip=' in
          * the original sb_mountdata
          */
-        md_len = strlen(sb_mountdata) + strlen(srvIP) +
-                strlen(ref->node_name) + 12;
+        md_len = strlen(sb_mountdata) + rc + strlen(ref->node_name) + 12;
         mountdata = kzalloc(md_len+1, GFP_KERNEL);
         if (mountdata == NULL) {
                 rc = -ENOMEM;
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 2eaebbd31132..1f5450814087 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -86,8 +86,8 @@ extern unsigned int smbCalcSize(struct smb_hdr *ptr);
 extern unsigned int smbCalcSize_LE(struct smb_hdr *ptr);
 extern int decode_negTokenInit(unsigned char *security_blob, int length,
                         struct TCP_Server_Info *server);
-extern int cifs_convert_address(struct sockaddr *dst, char *src);
-extern int cifs_fill_sockaddr(struct sockaddr *dst, char *src,
+extern int cifs_convert_address(struct sockaddr *dst, const char *src, int len);
+extern int cifs_fill_sockaddr(struct sockaddr *dst, const char *src, int len,
                                 unsigned short int port);
 extern int map_smb_to_linux_error(struct smb_hdr *smb, int logErr);
 extern void header_assemble(struct smb_hdr *, char /* command */ ,
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 2a43a0aca965..95c2ea67edfb 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1543,6 +1543,7 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
         if (volume_info->UNCip && volume_info->UNC) {
                 rc = cifs_fill_sockaddr((struct sockaddr *)&addr,
                                         volume_info->UNCip,
+                                        strlen(volume_info->UNCip),
                                         volume_info->port);
                 if (!rc) {
                         /* we failed translating address */
diff --git a/fs/cifs/dns_resolve.c b/fs/cifs/dns_resolve.c
index 3ad7f4300c45..aa967e7917f8 100644
--- a/fs/cifs/dns_resolve.c
+++ b/fs/cifs/dns_resolve.c
@@ -40,11 +40,11 @@ static const struct cred *dns_resolver_cache;
  *              0 - name is not IP
  */
 static int
-is_ip(char *name)
+is_ip(const char *name, int len)
 {
         struct sockaddr_storage ss;
 
-        return cifs_convert_address((struct sockaddr *)&ss, name);
+        return cifs_convert_address((struct sockaddr *)&ss, name, len);
 }
 
 static int
@@ -54,6 +54,10 @@ dns_resolver_instantiate(struct key *key, const void *data,
         int rc = 0;
         char *ip;
 
+        /* make sure this looks like an address */
+        if (!is_ip(data, datalen))
+                return -EINVAL;
+
         ip = kmalloc(datalen + 1, GFP_KERNEL);
         if (!ip)
                 return -ENOMEM;
@@ -61,12 +65,6 @@ dns_resolver_instantiate(struct key *key, const void *data,
         memcpy(ip, data, datalen);
         ip[datalen] = '\0';
 
-        /* make sure this looks like an address */
-        if (!is_ip(ip)) {
-                kfree(ip);
-                return -EINVAL;
-        }
-
         key->type_data.x[0] = datalen;
         key->payload.data = ip;
 
@@ -93,7 +91,7 @@ struct key_type key_type_dns_resolver = {
  *      unc - server UNC
  * output:
  *      *ip_addr - pointer to server ip, caller responcible for freeing it.
- * return 0 on success
+ * return the length of the returned string on success
  */
 int
 dns_resolve_server_name_to_ip(const char *unc, char **ip_addr)
@@ -131,7 +129,7 @@ dns_resolve_server_name_to_ip(const char *unc, char **ip_addr)
         memcpy(name, unc+2, len);
         name[len] = 0;
 
-        if (is_ip(name)) {
+        if (is_ip(name, len)) {
                 cFYI(1, "%s: it is IP, skipping dns upcall: %s",
                                         __func__, name);
                 data = name;
@@ -164,7 +162,7 @@ skip_upcall:
                                                         name,
                                                         *ip_addr
                                         );
-                        rc = 0;
+                        rc = len;
                 } else {
                         rc = -ENOMEM;
                 }
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) {