[pulseaudio-discuss] [PATCH] introspect: Fix ABI break introduced by b98a2e1

Luiz Augusto von Dentz luiz.dentz at gmail.com
Mon Nov 4 18:41:22 CET 2013


From: Luiz Augusto von Dentz <luiz.von.dentz at intel.com>

The size of pa_card_profile_info cannot change even if it just a field
appended to end because each entry is appended to a contiguous memory
and accessed by offset this may lead clients to access invalid data.

To fix a new struct called pa_card_profile_info2 is introduced and shall
be used for now on while pa_card_profile_info shall be considered
deprecated but it is still mantained for backward compatibility.

A new field called profiles2 is introduced to pa_card_info, this new field
is an array of pointers to pa_card_profile_info2 so it should be possible
to append new fields to the end of the pa_card_profile_info2 without
breaking binary compatibility as the entries are not accessed by offset.
---
 src/pulse/introspect.c | 73 ++++++++++++++++++++++++++++++++++----------------
 src/pulse/introspect.h | 26 +++++++++++++-----
 src/utils/pactl.c      |  8 +++---
 3 files changed, 73 insertions(+), 34 deletions(-)

diff --git a/src/pulse/introspect.c b/src/pulse/introspect.c
index 45e0115..b9fdb1c 100644
--- a/src/pulse/introspect.c
+++ b/src/pulse/introspect.c
@@ -769,6 +769,15 @@ static void card_info_free(pa_card_info* i) {
 
     pa_xfree(i->profiles);
 
+    if (i->n_profiles) {
+        uint32_t j;
+
+        for (j = 0; j < i->n_profiles; j++)
+             pa_xfree(i->profiles2[j]);
+
+        pa_xfree(i->profiles2);
+    }
+
     if (i->ports) {
         uint32_t j;
 
@@ -776,6 +785,8 @@ static void card_info_free(pa_card_info* i) {
             if (i->ports[j]) {
                 if (i->ports[j]->profiles)
                     pa_xfree(i->ports[j]->profiles);
+                if (i->ports[j]->profiles2)
+                    pa_xfree(i->ports[j]->profiles2);
                 if (i->ports[j]->proplist)
                     pa_proplist_free(i->ports[j]->proplist);
             }
@@ -829,6 +840,7 @@ static int fill_card_port_info(pa_context *context, pa_tagstruct* t, pa_card_inf
 
         if (port->n_profiles > 0) {
             port->profiles = pa_xnew0(pa_card_profile_info*, i->n_profiles+1);
+            port->profiles2 = pa_xnew0(pa_card_profile_info2*, i->n_profiles+1);
 
             for (k = 0; k < port->n_profiles; k++) {
                 const char* profilename;
@@ -839,6 +851,7 @@ static int fill_card_port_info(pa_context *context, pa_tagstruct* t, pa_card_inf
                 for (l = 0; l < i->n_profiles; l++) {
                     if (pa_streq(i->profiles[l].name, profilename)) {
                         port->profiles[k] = &i->profiles[l];
+                        port->profiles2[k] = i->profiles2[l];
                         break;
                     }
                 }
@@ -857,6 +870,40 @@ static int fill_card_port_info(pa_context *context, pa_tagstruct* t, pa_card_inf
     return 0;
 }
 
+static int fill_card_profile_info(pa_context *context, pa_tagstruct* t, pa_card_info* i) {
+    uint32_t j;
+
+    i->profiles = pa_xnew0(pa_card_profile_info, i->n_profiles+1);
+    i->profiles2 = pa_xnew0(pa_card_profile_info2*, i->n_profiles+1);
+
+    for (j = 0; j < i->n_profiles; j++) {
+        if (pa_tagstruct_gets(t, &i->profiles[j].name) < 0 ||
+            pa_tagstruct_gets(t, &i->profiles[j].description) < 0 ||
+            pa_tagstruct_getu32(t, &i->profiles[j].n_sinks) < 0 ||
+            pa_tagstruct_getu32(t, &i->profiles[j].n_sources) < 0 ||
+            pa_tagstruct_getu32(t, &i->profiles[j].priority) < 0)
+                return -PA_ERR_PROTOCOL;
+
+        i->profiles2[j] = pa_xnew0(pa_card_profile_info2, 1);
+        i->profiles2[j]->name = i->profiles[j].name;
+        i->profiles2[j]->description = i->profiles[j].description;
+        i->profiles2[j]->n_sinks = i->profiles[j].n_sinks;
+        i->profiles2[j]->n_sources = i->profiles[j].n_sources;
+        i->profiles2[j]->priority = i->profiles[j].priority;
+
+        if (context->version >= 29) {
+            uint32_t av;
+
+            if (pa_tagstruct_getu32(t, &av) < 0)
+                return -PA_ERR_PROTOCOL;
+
+            i->profiles2[j]->available = av;
+        }
+    }
+
+    return 0;
+}
+
 static void context_get_card_info_callback(pa_pdispatch *pd, uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata) {
     pa_operation *o = userdata;
     int eol = 1;
@@ -890,29 +937,8 @@ static void context_get_card_info_callback(pa_pdispatch *pd, uint32_t command, u
                     goto fail;
 
             if (i.n_profiles > 0) {
-                i.profiles = pa_xnew0(pa_card_profile_info, i.n_profiles+1);
-
-                for (j = 0; j < i.n_profiles; j++) {
-
-                    if (pa_tagstruct_gets(t, &i.profiles[j].name) < 0 ||
-                        pa_tagstruct_gets(t, &i.profiles[j].description) < 0 ||
-                        pa_tagstruct_getu32(t, &i.profiles[j].n_sinks) < 0 ||
-                        pa_tagstruct_getu32(t, &i.profiles[j].n_sources) < 0 ||
-                        pa_tagstruct_getu32(t, &i.profiles[j].priority) < 0)
-                            goto fail;
-
-                    i.profiles[j].available = 1;
-                    if (o->context->version >= 29) {
-                        uint32_t av;
-                        if (pa_tagstruct_getu32(t, &av) < 0)
-                            goto fail;
-                        i.profiles[j].available = av;
-                    }
-                }
-
-                /* Terminate with an extra NULL entry, just to make sure */
-                i.profiles[j].name = NULL;
-                i.profiles[j].description = NULL;
+                if (fill_card_profile_info(o->context, t, &i) < 0)
+                    goto fail;
             }
 
             i.proplist = pa_proplist_new();
@@ -929,6 +955,7 @@ static void context_get_card_info_callback(pa_pdispatch *pd, uint32_t command, u
                 for (j = 0; j < i.n_profiles; j++)
                     if (pa_streq(i.profiles[j].name, ap)) {
                         i.active_profile = &i.profiles[j];
+                        i.active_profile2 = i.profiles2[j];
                         break;
                     }
             }
diff --git a/src/pulse/introspect.h b/src/pulse/introspect.h
index f199a18..7a9314b 100644
--- a/src/pulse/introspect.h
+++ b/src/pulse/introspect.h
@@ -443,22 +443,31 @@ pa_operation* pa_context_kill_client(pa_context *c, uint32_t idx, pa_context_suc
 
 /** @{ \name Cards */
 
-/** Stores information about a specific profile of a card.  Please
- * note that this structure can be extended as part of evolutionary
- * API updates at any time in any new release. \since 0.9.15 */
+/** \deprecated Superseded by pa_card_profile_info2 \since 0.9.15 */
 typedef struct pa_card_profile_info {
     const char *name;                   /**< Name of this profile */
     const char *description;            /**< Description of this profile */
     uint32_t n_sinks;                   /**< Number of sinks this profile would create */
     uint32_t n_sources;                 /**< Number of sources this profile would create */
     uint32_t priority;                  /**< The higher this value is, the more useful this profile is as a default. */
+} pa_card_profile_info;
+
+/** Stores information about a specific profile of a card. Please
+ * note that this structure can be extended as part of evolutionary
+ * API updates at any time in any new release. \since 5.0 */
+typedef struct pa_card_profile_info2 {
+    const char *name;                   /**< Name of this profile */
+    const char *description;            /**< Description of this profile */
+    uint32_t n_sinks;                   /**< Number of sinks this profile would create */
+    uint32_t n_sources;                 /**< Number of sources this profile would create */
+    uint32_t priority;                  /**< The higher this value is, the more useful this profile is as a default. */
     int available;
     /**< Is this profile available? If this is zero, meaning "unavailable",
      * then it makes no sense to try to activate this profile. If this is
      * non-zero, it's still not a guarantee that activating the profile will
      * result in anything useful, it just means that the server isn't aware of
      * any reason why the profile would definitely be useless. \since 5.0 */
-} pa_card_profile_info;
+} pa_card_profile_info2;
 
 /** Stores information about a specific port of a card.  Please
  * note that this structure can be extended as part of evolutionary
@@ -470,9 +479,10 @@ typedef struct pa_card_port_info {
     int available;                      /**< A #pa_port_available enum, indicating availability status of this port. */
     int direction;                      /**< A #pa_direction enum, indicating the direction of this port. */
     uint32_t n_profiles;                /**< Number of entries in profile array */
-    pa_card_profile_info** profiles;    /**< Array of pointers to available profiles, or NULL. Array is terminated by an entry set to NULL. */
+    pa_card_profile_info** profiles;    /**< \deprecated Superseded by profiles2 */
     pa_proplist *proplist;              /**< Property list */
     int64_t latency_offset;             /**< Latency offset of the port that gets added to the sink/source latency when the port is active. \since 3.0 */
+    pa_card_profile_info2** profiles2;  /**< Array of pointers to available profiles, or NULL. Array is terminated by an entry set to NULL. */
 } pa_card_port_info;
 
 /** Stores information about cards. Please note that this structure
@@ -484,11 +494,13 @@ typedef struct pa_card_info {
     uint32_t owner_module;               /**< Index of the owning module, or PA_INVALID_INDEX. */
     const char *driver;                  /**< Driver name */
     uint32_t n_profiles;                 /**< Number of entries in profile array */
-    pa_card_profile_info* profiles;      /**< Array of available profile, or NULL. Array is terminated by an entry with name set to NULL. Number of entries is stored in n_profiles. */
-    pa_card_profile_info* active_profile; /**< Pointer to active profile in the array, or NULL. */
+    pa_card_profile_info* profiles;      /**< \deprecated Superseded by profiles2 */
+    pa_card_profile_info* active_profile; /**< \deprecated Superseded by active_profiles2 */
     pa_proplist *proplist;               /**< Property list */
     uint32_t n_ports;                    /**< Number of entries in port array */
     pa_card_port_info **ports;           /**< Array of pointers to ports, or NULL. Array is terminated by an entry set to NULL. */
+    pa_card_profile_info2** profiles2;    /**< Array of pointers to available profiles, or NULL. Array is terminated by an entry set to NULL. */
+    pa_card_profile_info2* active_profile2; /**< Pointer to active profile in the array, or NULL. */
 } pa_card_info;
 
 /** Callback prototype for pa_context_get_card_info_...() \since 0.9.15 */
diff --git a/src/utils/pactl.c b/src/utils/pactl.c
index df47caa..fd7ab73 100644
--- a/src/utils/pactl.c
+++ b/src/utils/pactl.c
@@ -571,12 +571,12 @@ static void get_card_info_callback(pa_context *c, const pa_card_info *i, int is_
     pa_xfree(pl);
 
     if (i->profiles) {
-        pa_card_profile_info *p;
+        pa_card_profile_info2 **p;
 
         printf(_("\tProfiles:\n"));
-        for (p = i->profiles; p->name; p++)
-            printf("\t\t%s: %s (sinks: %u, sources: %u, priority: %u, available: %s)\n", p->name,
-                p->description, p->n_sinks, p->n_sources, p->priority, pa_yes_no(p->available));
+        for (p = i->profiles2; *p; p++)
+            printf("\t\t%s: %s (sinks: %u, sources: %u, priority: %u, available: %s)\n", (*p)->name,
+                (*p)->description, (*p)->n_sinks, (*p)->n_sources, (*p)->priority, pa_yes_no((*p)->available));
     }
 
     if (i->active_profile)
-- 
1.8.3.1



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