C API interfacensanci/pr28284-webapi

3 files changed, 109 insertions, 23 deletions

diff --git a/debuginfod/debuginfod-client.c b/debuginfod/debuginfod-client.c
index 88e45567..b94b9209 100644
--- a/debuginfod/debuginfod-client.c
+++ b/debuginfod/debuginfod-client.c
@@ -127,7 +127,6 @@ struct debuginfod_client
      timeout or other info gotten from environment variables, the
      handle data, etc. So those don't have to be reparsed and
      recreated on each request.  */
-  char * winning_headers;
 };
 
 /* The cache_clean_interval_s file within the debuginfod cache specifies
@@ -187,6 +186,10 @@ struct handle_data
   /* Response http headers for this client handle, sent from the server */
   char *response_data;
   size_t response_data_size;
+
+  /* synonymous with 'describe', but used in the context of the 
+   * http response. */
+  char head_request;
 };
 
 static size_t
@@ -504,8 +507,7 @@ default_progressfn (debuginfod_client *c, long a, long b)
 
 /* This is a callback function that receives http response headers in buffer for use
  * in this program. https://curl.se/libcurl/c/CURLOPT_HEADERFUNCTION.html is the
- * online documentation.
- */
+ * online documentation.  */
 static size_t
 header_callback (char * buffer, size_t size, size_t numitems, void * userdata)
 {
@@ -514,6 +516,22 @@ header_callback (char * buffer, size_t size, size_t numitems, void * userdata)
   /* Temporary buffer for realloc */
   char *temp = NULL;
   struct handle_data *data = (struct handle_data *) userdata;
+  curl_off_t resp;
+  curl_easy_getinfo(data->handle, CURLINFO_RESPONSE_CODE, &resp);
+  if (*data->target_handle == NULL && 
+      (resp == 200 || resp == 406) && 
+      data->head_request)
+    {
+      *data->target_handle = data->handle;
+      /* update the client object */
+      const char *url = NULL;
+      (void) curl_easy_getinfo (data->handle, CURLINFO_EFFECTIVE_URL, &url);
+      if (url)
+        {
+          free (data->client->url);
+          data->client->url = strdup(url); /* ok if fails */
+        }
+    }
   if (data->response_data == NULL)
     {
       temp = malloc(numitems+1);
@@ -544,6 +562,7 @@ debuginfod_query_server (debuginfod_client *c,
 			 const unsigned char *build_id,
                          int build_id_len,
                          const char *type,
+                         const char describe,
                          const char *filename,
                          char **path)
 {
@@ -972,6 +991,11 @@ debuginfod_query_server (debuginfod_client *c,
         snprintf(data[i].url, PATH_MAX, "%s/%s/%s", server_url, build_id_bytes, type);
       if (vfd >= 0)
 	dprintf (vfd, "url %d %s\n", i, data[i].url);
+      data[i].head_request = describe;
+      /* PR28284 when describing simply send HEAD request
+       * (done with CURLOPT_NOBODY) */
+      if (describe)
+        curl_easy_setopt(data[i].handle, CURLOPT_NOBODY, 1);
 
       curl_easy_setopt(data[i].handle, CURLOPT_URL, data[i].url);
       if (vfd >= 0)
@@ -1017,10 +1041,11 @@ debuginfod_query_server (debuginfod_client *c,
   int still_running;
   long loops = 0;
   int committed_to = -1;
+  char *committed_response = NULL;
   bool verbose_reported = false;
   struct timespec start_time, cur_time;
-  c->winning_headers = NULL;
-  if ( maxtime > 0 && clock_gettime(CLOCK_MONOTONIC_RAW, &start_time) == -1)
+
+  if (maxtime > 0 && clock_gettime(CLOCK_MONOTONIC_RAW, &start_time) == -1)
     {
       rc = errno;
       goto out2;
@@ -1057,16 +1082,18 @@ debuginfod_query_server (debuginfod_client *c,
 	    else
               {
 	        committed_to = i;
-                if (c->winning_headers == NULL)
-                  {
-                    c->winning_headers = data[committed_to].response_data;
-                    if (vfd >= 0 && c->winning_headers != NULL)
-                      dprintf(vfd, "\n%s", c->winning_headers);
-                    data[committed_to].response_data = NULL;
+                if (committed_response == NULL)
+                    {
+                      committed_response = data[i].response_data;
+                      /* PR28284 if verbose or describing and winning headers exist
+                       * print them. */
+                      if ((vfd >= 0 || describe) && committed_response != NULL)
+                        dprintf(vfd, "%s\n", committed_response);
+                      data[i].response_data = NULL;
                   }
-
               }
-	}
+
+        }
 
       if (vfd >= 0 && !verbose_reported && committed_to >= 0)
 	{
@@ -1077,7 +1104,7 @@ debuginfod_query_server (debuginfod_client *c,
 	    c->default_progressfn_printed_p = 0;
 	  verbose_reported = true;
 	}
-
+      
       if (curlm_res != CURLM_OK)
         {
           switch (curlm_res)
@@ -1309,8 +1336,6 @@ debuginfod_query_server (debuginfod_client *c,
               curl_easy_cleanup (data[i].handle);
               free(data[i].response_data);
             }
-            free(c->winning_headers);
-            c->winning_headers = NULL;
 	    goto query_in_parallel;
 	}
       else
@@ -1347,7 +1372,12 @@ debuginfod_query_server (debuginfod_client *c,
       goto out2;
       /* Perhaps we need not give up right away; could retry or something ... */
     }
-
+  if (describe)
+    {
+      xalloc_str(*path,
+                 "X-DEBUGINFOD-URL: %s\n%s", c->url ?: "", committed_response);
+      // XXX: xalloc_str is wrong here (wrong goto out;)
+    }
   /* remove all handles from multi */
   for (int i = 0; i < num_urls; i++)
     {
@@ -1364,7 +1394,7 @@ debuginfod_query_server (debuginfod_client *c,
 
   /* don't close fd - we're returning it */
   /* don't unlink the tmppath; it's already been renamed. */
-  if (path != NULL)
+  if (path != NULL && !describe)
    *path = strdup(target_cache_path);
 
   rc = fd;
@@ -1407,7 +1437,7 @@ debuginfod_query_server (debuginfod_client *c,
   if (c->default_progressfn_printed_p)
     dprintf(STDERR_FILENO, "\n");
 
-  if (vfd >= 0)
+  if (vfd >= 0 && !describe)
     {
       if (rc < 0)
 	dprintf (vfd, "not found %s (err=%d)\n", strerror (-rc), rc);
@@ -1489,7 +1519,6 @@ debuginfod_end (debuginfod_client *client)
 
   curl_multi_cleanup (client->server_mhandle);
   curl_slist_free_all (client->headers);
-  free (client->winning_headers);
   free (client->url);
   free (client);
 }
@@ -1500,7 +1529,7 @@ debuginfod_find_debuginfo (debuginfod_client *client,
                            char **path)
 {
   return debuginfod_query_server(client, build_id, build_id_len,
-                                 "debuginfo", NULL, path);
+                                 "debuginfo", 0, NULL, path);
 }
 
 
@@ -1511,7 +1540,7 @@ debuginfod_find_executable(debuginfod_client *client,
                            char **path)
 {
   return debuginfod_query_server(client, build_id, build_id_len,
-                                 "executable", NULL, path);
+                                 "executable", 0, NULL, path);
 }
 
 /* See debuginfod.h  */
@@ -1520,9 +1549,39 @@ int debuginfod_find_source(debuginfod_client *client,
                            const char *filename, char **path)
 {
   return debuginfod_query_server(client, build_id, build_id_len,
-                                 "source", filename, path);
+                                 "source", 0, filename, path);
 }
 
+/*  See debuginfod.h */
+int
+debuginfod_describe_debuginfo (debuginfod_client *client,
+			   const unsigned char *build_id, int build_id_len,
+                           char **header)
+{
+  return debuginfod_query_server(client, build_id, build_id_len,
+                                           "debuginfo", 1, NULL, header);
+}
+
+
+/* See debuginfod.h  */
+int
+debuginfod_describe_executable(debuginfod_client *client,
+			   const unsigned char *build_id, int build_id_len,
+                           char **header)
+{
+  return debuginfod_query_server(client, build_id, build_id_len,
+                                           "executable", 1, NULL, header);
+}
+
+/* See debuginfod.h  */
+int
+debuginfod_describe_source(debuginfod_client *client,
+			   const unsigned char *build_id, int build_id_len,
+                           const char *filename, char **header)
+{
+  return debuginfod_query_server(client, build_id, build_id_len,
+                                           "source", 1, filename, header);
+}
 
 /* Add an outgoing HTTP header.  */
 int debuginfod_add_http_header (debuginfod_client *client, const char* header)
diff --git a/debuginfod/debuginfod.h.in b/debuginfod/debuginfod.h.in
index c358df4d..50240c4b 100644
--- a/debuginfod/debuginfod.h.in
+++ b/debuginfod/debuginfod.h.in
@@ -78,6 +78,28 @@ int debuginfod_find_source (debuginfod_client *client,
                             const char *filename,
                             char **path);
 
+/* The _describe_ variants of the query functions return a set of HTTP-like
+   headers that would result from a new lookup.  No content is collected. 
+   If successful, return zero, otherwise return a posix error code.  If
+   successful, set *headers a strdup()'d copy of the headers.
+   Caller must free() it later. */
+
+int debuginfod_describe_debuginfo (debuginfod_client *client,
+                                   const unsigned char *build_id,
+                                   int build_id_len,
+                                   char **headers);
+
+int debuginfod_describe_executable (debuginfod_client *client,
+                                    const unsigned char *build_id,
+                                    int build_id_len,
+                                    char **headers);
+
+int debuginfod_describe_source (debuginfod_client *client,
+                                const unsigned char *build_id,
+                                int build_id_len,
+                                const char *filename,
+                                char **headers);
+  
 typedef int (*debuginfod_progressfn_t)(debuginfod_client *c, long a, long b);
 void debuginfod_set_progressfn(debuginfod_client *c,
 			       debuginfod_progressfn_t fn);
diff --git a/debuginfod/libdebuginfod.map b/debuginfod/libdebuginfod.map
index 7d2f5882..480f7bf8 100644
--- a/debuginfod/libdebuginfod.map
+++ b/debuginfod/libdebuginfod.map
@@ -18,3 +18,8 @@ ELFUTILS_0.179 {
 ELFUTILS_0.183 {
   debuginfod_set_verbose_fd;
 } ELFUTILS_0.179;
+ELFUTILS_0.186 {
+  debuginfod_describe_debuginfo;
+  debuginfod_describe_executable;
+  debuginfod_describe_source;
+} ELFUTILS_0.183;