Refactor sym_upload in tools to extract code into common/linux, and minor fixes

src/common/linux/http_upload.cc

 // Copyright (c) 2006, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
@@ skipping 54 matching lines @@
                              string *error_description) {
   if (response_code != NULL)
     *response_code = 0;
 
   if (!CheckParameters(parameters))
     return false;
 
   // We may have been linked statically; if curl_easy_init is in the
   // current binary, no need to search for a dynamic version.
   void* curl_lib = dlopen(NULL, RTLD_NOW);
-  if (!curl_lib || dlsym(curl_lib, "curl_easy_init") == NULL) {
+  if (!CheckCurlLib(curl_lib)) {
+    fprintf(stderr,
+            "Failed to open curl lib from binary, use libcurl.so instead\n");
     dlerror();  // Clear dlerror before attempting to open libraries.
     dlclose(curl_lib);
     curl_lib = NULL;
   }
   if (!curl_lib) {
     curl_lib = dlopen("libcurl.so", RTLD_NOW);
   }
   if (!curl_lib) {
     if (error_description != NULL)
       *error_description = dlerror();
@@ skipping 20 matching lines @@
   if (!curl) {
     dlclose(curl_lib);
     return false;
   }
 
   CURLcode err_code = CURLE_OK;
   CURLcode (*curl_easy_setopt)(CURL *, CURLoption, ...);
   *(void**) (&curl_easy_setopt) = dlsym(curl_lib, "curl_easy_setopt");
   (*curl_easy_setopt)(curl, CURLOPT_URL, url.c_str());
   (*curl_easy_setopt)(curl, CURLOPT_USERAGENT, kUserAgent);
+  // Support multithread by disabling timeout handling, would get SIGSEGV with
+  // Curl_resolv_timeout in stack trace otherwise.
+  // See https://curl.haxx.se/libcurl/c/threadsafe.html
+  (*curl_easy_setopt)(curl, CURLOPT_NOSIGNAL, 1);
   // Set proxy information if necessary.
   if (!proxy.empty())
     (*curl_easy_setopt)(curl, CURLOPT_PROXY, proxy.c_str());
   if (!proxy_user_pwd.empty())
     (*curl_easy_setopt)(curl, CURLOPT_PROXYUSERPWD, proxy_user_pwd.c_str());
 
   if (!ca_certificate_file.empty())
     (*curl_easy_setopt)(curl, CURLOPT_CAINFO, ca_certificate_file.c_str());
 
   struct curl_httppost *formpost = NULL;
@@ skipping 65 matching lines @@
   if (headerlist != NULL) {
     void (*curl_slist_free_all)(struct curl_slist *);
     *(void**) (&curl_slist_free_all) = dlsym(curl_lib, "curl_slist_free_all");
     (*curl_slist_free_all)(headerlist);
   }
   dlclose(curl_lib);
   return err_code == CURLE_OK;
 }
 
 // static
+bool HTTPUpload::CheckCurlLib(void* curl_lib) {
+  return curl_lib &&
+      dlsym(curl_lib, "curl_easy_init") &&
+      dlsym(curl_lib, "curl_easy_setopt");
+}
+
+// static
 bool HTTPUpload::CheckParameters(const map<string, string> &parameters) {
   for (map<string, string>::const_iterator pos = parameters.begin();
        pos != parameters.end(); ++pos) {
     const string &str = pos->first;
     if (str.size() == 0)
       return false;  // disallow empty parameter names
     for (unsigned int i = 0; i < str.size(); ++i) {
       int c = str[i];
       if (c < 32 || c == '"' || c > 127) {
         return false;
       }
     }
   }
   return true;
 }
 
 }  // namespace google_breakpad