PR28284: add tweaks on previous debuginfod x-debuginfod* header forwarding work

Embrace case-independent headers, more fully document, handle HTTP \r.
In addition to test case, hand-tested against fedora debuginfod
instances, running federated servers under valgrind.

Signed-off-by: Frank Ch. Eigler <fche@redhat.com>

6 files changed, 47 insertions, 30 deletions

diff --git a/debuginfod/ChangeLog b/debuginfod/ChangeLog
index 8c843f3a..bc6c11c9 100644
--- a/debuginfod/ChangeLog
+++ b/debuginfod/ChangeLog
@@ -1,11 +1,21 @@
+2022-09-06  Frank Ch. Eigler  <fche@redhat.com>
+
+	* debuginfod-client.c (header_callback): Don't copy \r in x-d headers.
+	Print all headers in verbose_fd mode.
+	* debuginfod-find.c (parse_opt): Set verbose_fd only at verbosity >= 2.
+	* debuginfod.cxx (handle_buildid): Clean up header forwarding
+	string processing.
+	* debuginfod.h.in: (debuginfod_get_headers): Tweak wording.
+	* libdebuginfod.map: Use ELFUTILS_0.188 for new function.
+
 2022-07-15  Noah Sanci  <nsanci@redhat.com>
 
-	* debuginfod-client.c (header_callback): Handle headers without
+	* debuginfod-client.c (header_callback): Ignore headers without
 	X-DEBUGINFOD prefix.
 	(debuginfod_query_server): Removed verbose printing headers when
 	undesired.
 	(debuginfod_get_headers): Created.
-	* debuginfod-find.c (main): Verboes printing headers.
+	* debuginfod-find.c (main): Verbose printing headers.
 	* debuginfod.cxx (handle_buildid): Add headers prefixed with
 	X-DEBUGINFOD from federated servers to this server's response
 	headers.
diff --git a/debuginfod/debuginfod-client.c b/debuginfod/debuginfod-client.c
index a3565f57..54dc3f2f 100644
--- a/debuginfod/debuginfod-client.c
+++ b/debuginfod/debuginfod-client.c
@@ -499,33 +499,37 @@ default_progressfn (debuginfod_client *c, long a, long b)
 static size_t
 header_callback (char * buffer, size_t size, size_t numitems, void * userdata)
 {
+  struct handle_data *data = (struct handle_data *) userdata;
   if (size != 1)
     return 0;
-  // X-DEBUGINFOD is 11 characters long.
+  if (data->client && data->client->verbose_fd >= 0)
+    dprintf (data->client->verbose_fd, "header %.*s", (int)numitems, buffer);
   // Some basic checks to ensure the headers received are of the expected format
-  if ( strncmp(buffer, "X-DEBUGINFOD", 11) || buffer[numitems-1] != '\n'
-       || (buffer == strstr(buffer, ":")) ){
+  if (strncasecmp(buffer, "X-DEBUGINFOD", 11)
+      || buffer[numitems-2] != '\r'
+      || buffer[numitems-1] != '\n'
+      || (buffer == strstr(buffer, ":")) ){
     return numitems;
   }
   /* Temporary buffer for realloc */
   char *temp = NULL;
-  struct handle_data *data = (struct handle_data *) userdata;
   if (data->response_data == NULL)
     {
-      temp = malloc(numitems+1);
+      temp = malloc(numitems);
       if (temp == NULL)
         return 0;
     }
   else
     {
-      temp = realloc(data->response_data, data->response_data_size + numitems + 1);
+      temp = realloc(data->response_data, data->response_data_size + numitems);
       if (temp == NULL)
         return 0;
     }
 
-  memcpy(temp + data->response_data_size, buffer, numitems);
+  memcpy(temp + data->response_data_size, buffer, numitems-1);
   data->response_data = temp;
-  data->response_data_size += numitems;
+  data->response_data_size += numitems-1;
+  data->response_data[data->response_data_size-1] = '\n';
   data->response_data[data->response_data_size] = '\0';
   return numitems;
 }
@@ -1072,11 +1076,9 @@ debuginfod_query_server (debuginfod_client *c,
   int committed_to = -1;
   bool verbose_reported = false;
   struct timespec start_time, cur_time;
-  if (c->winning_headers != NULL)
-    {
-      free (c->winning_headers);
-      c->winning_headers = NULL;
-    }
+
+  free (c->winning_headers);
+  c->winning_headers = NULL;
   if ( maxtime > 0 && clock_gettime(CLOCK_MONOTONIC_RAW, &start_time) == -1)
     {
       rc = errno;
diff --git a/debuginfod/debuginfod-find.c b/debuginfod/debuginfod-find.c
index fb1f294c..778fb09b 100644
--- a/debuginfod/debuginfod-find.c
+++ b/debuginfod/debuginfod-find.c
@@ -99,7 +99,8 @@ static error_t parse_opt (int key, char *arg, struct argp_state *state)
     {
     case 'v': verbose++;
       debuginfod_set_progressfn (client, & progressfn);
-      debuginfod_set_verbose_fd (client, STDERR_FILENO);
+      if (verbose > 1)
+        debuginfod_set_verbose_fd (client, STDERR_FILENO);
       break;
     default: return ARGP_ERR_UNKNOWN;
     }
diff --git a/debuginfod/debuginfod.cxx b/debuginfod/debuginfod.cxx
index 27b671d3..000a41c4 100644
--- a/debuginfod/debuginfod.cxx
+++ b/debuginfod/debuginfod.cxx
@@ -2093,22 +2093,26 @@ and will not query the upstream servers");
             {
               add_mhd_response_header (r, "Content-Type",
 				       "application/octet-stream");
+              // Copy the incoming headers
               const char * hdrs = debuginfod_get_headers(client);
               string header_dup;
               if (hdrs)
                 header_dup = string(hdrs);
-              size_t pos = 0;
-              // Clean winning headers to add all X-DEBUGINFOD lines to the package we'll send
-              while( (pos = header_dup.find("X-DEBUGINFOD")) != string::npos)
+              // Parse the "header: value\n" lines into (h,v) tuples and pass on
+              while(1)
                 {
-                  // Focus on where X-DEBUGINFOD- begins
-                  header_dup = header_dup.substr(pos);
-                  size_t newline =  header_dup.find('\n');
-                  if (newline == string::npos)
-                    break;
-                  add_mhd_response_header(r, header_dup.substr(0,header_dup.find(':')).c_str(),
-                                             header_dup.substr(header_dup.find(':')).c_str());
-                  header_dup = header_dup.substr(newline);
+                  size_t newline = header_dup.find('\n');
+                  if (newline == string::npos) break;
+                  size_t colon = header_dup.find(':');
+                  if (colon == string::npos) break;
+                  string header = header_dup.substr(0,colon);
+                  string value = header_dup.substr(colon+1,newline-colon-1);
+                  // strip leading spaces from value
+                  size_t nonspace = value.find_first_not_of(" ");
+                  if (nonspace != string::npos)
+                    value = value.substr(nonspace);
+                  add_mhd_response_header(r, header.c_str(), value.c_str());
+                  header_dup = header_dup.substr(newline+1);
                 }
 
               add_mhd_last_modified (r, s.st_mtime);
diff --git a/debuginfod/debuginfod.h.in b/debuginfod/debuginfod.h.in
index 6ae8b91c..40b1ea00 100644
--- a/debuginfod/debuginfod.h.in
+++ b/debuginfod/debuginfod.h.in
@@ -93,8 +93,8 @@ void* debuginfod_get_user_data (debuginfod_client *client);
 /* Get the current or last active URL, if known.  */
 const char* debuginfod_get_url (debuginfod_client *client);
 
-/* Returns all headers sent to this client which were prefixed
- * with X-DEBUGINFOD */
+/* Returns set of x-debuginfod* header lines received from current or
+   last active transfer, \n separated, if known. */
 const char* debuginfod_get_headers(debuginfod_client *client);
 
 /* Add an outgoing HTTP request  "Header: Value".  Copies string.  */
diff --git a/debuginfod/libdebuginfod.map b/debuginfod/libdebuginfod.map
index f95b5b9a..93964167 100644
--- a/debuginfod/libdebuginfod.map
+++ b/debuginfod/libdebuginfod.map
@@ -18,6 +18,6 @@ ELFUTILS_0.179 {
 ELFUTILS_0.183 {
   debuginfod_set_verbose_fd;
 } ELFUTILS_0.179;
-ELFUTILS_0.189 {
+ELFUTILS_0.188 {
   debuginfod_get_headers;
 } ELFUTILS_0.183;