Improve error checking in many places

6 files changed, 59 insertions, 11 deletions

diff --git a/backends/oss/oss-backend.c b/backends/oss/oss-backend.c
index 70b32be..9726570 100644
--- a/backends/oss/oss-backend.c
+++ b/backends/oss/oss-backend.c
@@ -298,7 +298,7 @@ read_devices (OssBackend *oss)
 
     for (i = 0; i < OSS_MAX_DEVICES; i++) {
         gchar   *path;
-        gboolean added_current = FALSE;
+        gboolean added_current;
 
         path = g_strdup_printf ("/dev/mixer%i", i);
 
@@ -333,6 +333,8 @@ read_device (OssBackend *oss, const gchar *path, gboolean *added)
     gchar     *bname;
     gchar     *label;
 
+    *added = FALSE;
+
     fd = g_open (path, O_RDWR, 0);
     if (fd == -1) {
         if (errno != ENOENT && errno != ENXIO)
@@ -360,11 +362,13 @@ read_device (OssBackend *oss, const gchar *path, gboolean *added)
 
     close (fd);
 
-    if ((*added = oss_device_open (device)) == TRUE)
-        add_device (oss, device);
-    else
-        g_object_unref (device);
-
+    if G_LIKELY (device != NULL) {
+        *added = oss_device_open (device);
+        if (*added == TRUE)
+            add_device (oss, device);
+        else
+            g_object_unref (device);
+    }
     return *added;
 }
 
diff --git a/backends/oss/oss-device.c b/backends/oss/oss-device.c
index e89e6e8..70f46e6 100644
--- a/backends/oss/oss-device.c
+++ b/backends/oss/oss-device.c
@@ -274,18 +274,26 @@ oss_device_new (const gchar *name,
                 gint         fd)
 {
     OssDevice *device;
+    gint       newfd;
 
     g_return_val_if_fail (name  != NULL, NULL);
     g_return_val_if_fail (label != NULL, NULL);
     g_return_val_if_fail (path  != NULL, NULL);
 
+    newfd = dup (fd);
+    if (newfd == -1) {
+        g_warning ("Failed to duplicate file descriptor: %s",
+                   g_strerror (errno));
+        return NULL;
+    }
+
     device = g_object_new (OSS_TYPE_DEVICE,
                            "name", name,
                            "label", label,
                            "icon", OSS_DEVICE_ICON,
                            NULL);
 
-    device->priv->fd   = dup (fd);
+    device->priv->fd   = newfd;
     device->priv->path = g_strdup (path);
 
     return device;
@@ -584,6 +592,8 @@ read_mixer_devices (OssDevice *device)
                                           device->priv->fd,
                                           i,
                                           stereo);
+        if G_UNLIKELY (control == NULL)
+            continue;
 
         if (oss_stream_has_controls (stream) == FALSE) {
             const gchar *name =
diff --git a/backends/oss/oss-stream-control.c b/backends/oss/oss-stream-control.c
index 0307fc7..9bdd3a5 100644
--- a/backends/oss/oss-stream-control.c
+++ b/backends/oss/oss-stream-control.c
@@ -24,6 +24,7 @@
 #include <libmatemixer/matemixer-private.h>
 
 #include "oss-common.h"
+#include "oss-stream.h"
 #include "oss-stream-control.h"
 
 #define OSS_VOLUME_JOIN(left,right)   (((left) & 0xFF) | (((right) & 0xFF) << 8))
@@ -136,10 +137,19 @@ oss_stream_control_new (const gchar               *name,
                         gboolean                   stereo)
 {
     OssStreamControl           *control;
+    gint                        newfd;
     MateMixerStreamControlFlags flags;
 
     g_return_val_if_fail (name  != NULL, NULL);
     g_return_val_if_fail (label != NULL, NULL);
+    g_return_val_if_fail (OSS_IS_STREAM (stream), NULL);
+
+    newfd = dup (fd);
+    if (newfd == -1) {
+        g_warning ("Failed to duplicate file descriptor: %s",
+                   g_strerror (errno));
+        return NULL;
+    }
 
     flags = MATE_MIXER_STREAM_CONTROL_VOLUME_READABLE |
             MATE_MIXER_STREAM_CONTROL_VOLUME_WRITABLE;
@@ -154,7 +164,7 @@ oss_stream_control_new (const gchar               *name,
                             "stream", stream,
                             NULL);
 
-    control->priv->fd = fd;
+    control->priv->fd = newfd;
     control->priv->devnum = devnum;
     control->priv->stereo = stereo;
     return control;
@@ -367,18 +377,24 @@ oss_stream_control_get_min_volume (MateMixerStreamControl *mmsc)
 static guint
 oss_stream_control_get_max_volume (MateMixerStreamControl *mmsc)
 {
+    g_return_val_if_fail (OSS_IS_STREAM_CONTROL (mmsc), 0);
+
     return 100;
 }
 
 static guint
 oss_stream_control_get_normal_volume (MateMixerStreamControl *mmsc)
 {
+    g_return_val_if_fail (OSS_IS_STREAM_CONTROL (mmsc), 0);
+
     return 100;
 }
 
 static guint
 oss_stream_control_get_base_volume (MateMixerStreamControl *mmsc)
 {
+    g_return_val_if_fail (OSS_IS_STREAM_CONTROL (mmsc), 0);
+
     return 100;
 }
 
diff --git a/backends/oss/oss-stream.c b/backends/oss/oss-stream.c
index 0e7a0c0..f094537 100644
--- a/backends/oss/oss-stream.c
+++ b/backends/oss/oss-stream.c
@@ -21,6 +21,7 @@
 #include <libmatemixer/matemixer.h>
 #include <libmatemixer/matemixer-private.h>
 
+#include "oss-device.h"
 #include "oss-stream.h"
 #include "oss-stream-control.h"
 #include "oss-switch.h"
@@ -93,7 +94,12 @@ oss_stream_new (const gchar       *name,
                 MateMixerDevice   *device,
                 MateMixerDirection direction)
 {
-    const gchar *label = mate_mixer_device_get_label (device);
+    const gchar *label;
+
+    g_return_val_if_fail (name != NULL, NULL);
+    g_return_val_if_fail (OSS_IS_DEVICE (device), NULL);
+
+    label = mate_mixer_device_get_label (device);
 
     return g_object_new (OSS_TYPE_STREAM,
                          "name", name,
@@ -208,6 +214,8 @@ oss_stream_set_switch_data (OssStream *stream, gint fd, GList *options)
                                           _("Connector"),
                                           fd,
                                           options);
+    if G_UNLIKELY (stream->priv->swtch == NULL)
+        return;
 
     /* Read the active selection */
     oss_switch_load (stream->priv->swtch);
diff --git a/backends/oss/oss-switch-option.c b/backends/oss/oss-switch-option.c
index 862133d..544f321 100644
--- a/backends/oss/oss-switch-option.c
+++ b/backends/oss/oss-switch-option.c
@@ -53,6 +53,9 @@ oss_switch_option_new (const gchar *name,
 {
     OssSwitchOption *option;
 
+    g_return_val_if_fail (name  != NULL, NULL);
+    g_return_val_if_fail (label != NULL, NULL);
+
     option = g_object_new (OSS_TYPE_SWITCH_OPTION,
                            "name", name,
                            "label", label,
diff --git a/backends/oss/oss-switch.c b/backends/oss/oss-switch.c
index 6b78833..ba07d36 100644
--- a/backends/oss/oss-switch.c
+++ b/backends/oss/oss-switch.c
@@ -107,13 +107,20 @@ oss_switch_new (OssStream   *stream,
                 GList       *options)
 {
     OssSwitch *swtch;
+    gint       newfd;
 
     g_return_val_if_fail (OSS_IS_STREAM (stream), NULL);
     g_return_val_if_fail (name != NULL, NULL);
     g_return_val_if_fail (label != NULL, NULL);
-    g_return_val_if_fail (fd != -1, NULL);
     g_return_val_if_fail (options != NULL, NULL);
 
+    newfd = dup (fd);
+    if (newfd == -1) {
+        g_warning ("Failed to duplicate file descriptor: %s",
+                   g_strerror (errno));
+        return NULL;
+    }
+
     swtch = g_object_new (OSS_TYPE_SWITCH,
                           "name", name,
                           "label", label,
@@ -122,7 +129,7 @@ oss_switch_new (OssStream   *stream,
                           NULL);
 
     /* Takes ownership of options */
-    swtch->priv->fd      = dup (fd);
+    swtch->priv->fd      = newfd;
     swtch->priv->options = options;
 
     return swtch;