[Spice-devel] [PATCH 3/3] reds: Use g_strlcpy instead of strncpy

[Christophe Fergeau]

reds.c is using strncpy with a length one byte less than the
destination buffer size, and is relying on the fact that the
destination buffers are static global variables.
Now that we depend on glib, we can use g_strlcpy instead, which
avoids relying on such a subtle trick to get a nul-terminated
string.
---
 server/reds.c | 32 +++++++++++++++++---------------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/server/reds.c b/server/reds.c
index afa36d5..625163f 100644
--- a/server/reds.c
+++ b/server/reds.c
@@ -47,6 +47,8 @@
 #include <sasl/sasl.h>
 #endif
 
+#include <glib.h>
+
 #include <spice/protocol.h>
 #include <spice/vd_agent.h>
 #include <spice/stats.h>
@@ -352,7 +354,7 @@ StatNodeRef stat_add_node(StatNodeRef parent, const char *name, int visible)
     spice_assert(!(node->flags & SPICE_STAT_NODE_FLAG_ENABLED));
     node->value = 0;
     node->flags = SPICE_STAT_NODE_FLAG_ENABLED | (visible ? SPICE_STAT_NODE_FLAG_VISIBLE : 0);
-    strncpy(node->name, name, sizeof(node->name));
+    g_strlcpy(node->name, name, sizeof(node->name));
     insert_stat_node(parent, ref);
     pthread_mutex_unlock(&reds->stat_lock);
     return ref;
@@ -3953,7 +3955,7 @@ SPICE_GNUC_VISIBLE int spice_server_set_port(SpiceServer *s, int port)
 SPICE_GNUC_VISIBLE void spice_server_set_addr(SpiceServer *s, const char *addr, int flags)
 {
     spice_assert(reds == s);
-    strncpy(spice_addr, addr, sizeof(spice_addr)-1);
+    g_strlcpy(spice_addr, addr, sizeof(spice_addr));
     if (flags & SPICE_ADDR_FLAG_IPV4_ONLY) {
         spice_family = PF_INET;
     }
@@ -4044,7 +4046,7 @@ SPICE_GNUC_VISIBLE int spice_server_set_ticket(SpiceServer *s,
         taTicket.expiration_time = now + lifetime;
     }
     if (passwd != NULL) {
-        strncpy(taTicket.password, passwd, sizeof(taTicket.password)-1);
+        g_strlcpy(taTicket.password, passwd, sizeof(taTicket.password));
     } else {
         memset(taTicket.password, 0, sizeof(taTicket.password));
         taTicket.expiration_time = 0;
@@ -4068,24 +4070,24 @@ SPICE_GNUC_VISIBLE int spice_server_set_tls(SpiceServer *s, int port,
     memset(&ssl_parameters, 0, sizeof(ssl_parameters));
 
     spice_secure_port = port;
-    strncpy(ssl_parameters.ca_certificate_file, ca_cert_file,
-            sizeof(ssl_parameters.ca_certificate_file)-1);
-    strncpy(ssl_parameters.certs_file, certs_file,
-            sizeof(ssl_parameters.certs_file)-1);
-    strncpy(ssl_parameters.private_key_file, private_key_file,
-            sizeof(ssl_parameters.private_key_file)-1);
+    g_strlcpy(ssl_parameters.ca_certificate_file, ca_cert_file,
+              sizeof(ssl_parameters.ca_certificate_file));
+    g_strlcpy(ssl_parameters.certs_file, certs_file,
+              sizeof(ssl_parameters.certs_file));
+    g_strlcpy(ssl_parameters.private_key_file, private_key_file,
+              sizeof(ssl_parameters.private_key_file));
 
     if (key_passwd) {
-        strncpy(ssl_parameters.keyfile_password, key_passwd,
-                sizeof(ssl_parameters.keyfile_password)-1);
+        g_strlcpy(ssl_parameters.keyfile_password, key_passwd,
+                  sizeof(ssl_parameters.keyfile_password));
     }
     if (ciphersuite) {
-        strncpy(ssl_parameters.ciphersuite, ciphersuite,
-                sizeof(ssl_parameters.ciphersuite)-1);
+        g_strlcpy(ssl_parameters.ciphersuite, ciphersuite,
+                  sizeof(ssl_parameters.ciphersuite));
     }
     if (dh_key_file) {
-        strncpy(ssl_parameters.dh_key_file, dh_key_file,
-                sizeof(ssl_parameters.dh_key_file)-1);
+        g_strlcpy(ssl_parameters.dh_key_file, dh_key_file,
+                  sizeof(ssl_parameters.dh_key_file));
     }
     return 0;
 }
-- 
1.8.0