Printing curl library versions and used features

- Moved argument parsing "decisions" into main()
- getopt() handling changes, test OPR_PARSING_ERROR
  with "-j" and "-i" argument strings.
- Minimal libcurl version raised to 7.66.0, so
  no need to check CURL_VERSION_HTTP3 availability.
- Raised hardcoded version.

Author: baranyaib90

CMakeLists.txt

@@ -117,7 +117,7 @@ define_file_basename_for_sources("https_dns_proxy")
 
 if(SW_VERSION)
   set_source_files_properties(
-    src/options.c
+    src/main.c
     PROPERTIES COMPILE_FLAGS "-DSW_VERSION='\"${SW_VERSION}\"'")
 endif()
 

README.md

@@ -43,7 +43,7 @@ only makes sense if you trust your DoH provider.
 
 ## Build
 
-Depends on `c-ares (>=1.11.0)`, `libcurl (>=7.65.0)`, `libev (>=4.25)`.
+Depends on `c-ares (>=1.11.0)`, `libcurl (>=7.66.0)`, `libev (>=4.25)`.
 
 On Debian-derived systems those are libc-ares-dev,
 libcurl4-{openssl,nss,gnutls}-dev and libev-dev respectively.
@@ -208,7 +208,7 @@ Usage: ./https_dns_proxy [-a <listen_addr>] [-p <listen_port>]
   -F log_limit           Flight recorder: storing desired amount of logs from all levels
                          in memory and dumping them on fatal error or on SIGUSR2 signal.
                          (Default: 0, Disabled: 0, Min: 100, Max: 100000)
-  -V                     Print version and exit.
+  -V                     Print versions and exit.
   -h                     Print help and exit.
 ```
 

src/https_client.c

@@ -235,10 +235,8 @@ static const char * http_version_str(const long version) {
     case CURL_HTTP_VERSION_2_0: // fallthrough
     case CURL_HTTP_VERSION_2TLS:
       return "2";
-#ifdef CURL_VERSION_HTTP3
     case CURL_HTTP_VERSION_3:
       return "3";
-#endif
     default:
       FLOG("Unsupported HTTP version: %d", version);
   }
@@ -255,9 +253,7 @@ static void https_set_request_version(https_client_t *client,
     case 2:
       break;
     case 3:
-#ifdef CURL_VERSION_HTTP3
       http_version_int = CURL_HTTP_VERSION_3;
-#endif
       break;
     default:
       FLOG_REQ("Invalid HTTP version: %d", client->opt->use_http_version);

src/main.c

@@ -205,38 +205,79 @@ static int proxy_supports_name_resolution(const char *proxy)
   return 0;
 }
 
+static const char * sw_version(void) {
+#ifdef SW_VERSION
+  return SW_VERSION;
+#else
+  return "2025.5.10-atLeast";  // update date sometimes, like 1-2 times a year
+#endif
+}
+
 int main(int argc, char *argv[]) {
   struct Options opt;
   options_init(&opt);
-  if (options_parse_args(&opt, argc, argv)) {
-    options_show_usage(argc, argv);
-    exit(1);
+  switch (options_parse_args(&opt, argc, argv)) {
+    case OPR_SUCCESS:
+      break;
+    case OPR_HELP:
+      options_show_usage(argc, argv);
+      exit(0);  // asking for help is not a problem
+    case OPR_VERSION: {
+      printf("%s\n", sw_version());
+      CURLcode init_res = curl_global_init(CURL_GLOBAL_DEFAULT);
+      curl_version_info_data *curl_ver = curl_version_info(CURLVERSION_NOW);
+      if (init_res == CURLE_OK && curl_ver != NULL) {
+        printf("Using: ev/%d.%d c-ares/%s %s\n",
+               ev_version_major(), ev_version_minor(),
+               ares_version(NULL), curl_version());
+        printf("Features: %s%s%s\n",
+               curl_ver->features & CURL_VERSION_HTTP2 ? "HTTP2 " : "",
+               curl_ver->features & CURL_VERSION_HTTP3 ? "HTTP3 " : "",
+               curl_ver->features & CURL_VERSION_IPV6  ? "IPV6"   : "");
+        exit(0);
+      } else {
+        printf("\nFailed to get curl version info!\n");
+        exit(1);
+      }
+    }
+    case OPR_PARSING_ERROR:
+      printf("Failed to parse options!\n");
+      // fallthrough
+    case OPR_OPTION_ERROR:
+      printf("\n");
+      options_show_usage(argc, argv);
+      exit(1);
+    default:
+      abort();  // must not happen
   }
 
   logging_init(opt.logfd, opt.loglevel, opt.flight_recorder_size);
 
-  ILOG("Version: %s", options_sw_version());
+  ILOG("Version: %s", sw_version());
   ILOG("Built: " __DATE__ " " __TIME__);
-  ILOG("System c-ares: %s", ares_version(NULL));
-  ILOG("System libcurl: %s", curl_version());
+  ILOG("System ev library: %d.%d", ev_version_major(), ev_version_minor());
+  ILOG("System c-ares library: %s", ares_version(NULL));
+  ILOG("System curl library: %s", curl_version());
 
   // Note: curl intentionally uses uninitialized stack variables and similar
   // tricks to increase it's entropy pool. This confuses valgrind and leaks
   // through to errors about use of uninitialized values in our code. :(
-  curl_global_init(CURL_GLOBAL_DEFAULT);
+  CURLcode code = curl_global_init(CURL_GLOBAL_DEFAULT);
+  if (code != CURLE_OK) {
+    FLOG("Failed to initialize curl, error code %d: %s",
+         code, curl_easy_strerror(code));
+  }
 
   curl_version_info_data *curl_ver = curl_version_info(CURLVERSION_NOW);
+  if (curl_ver == NULL) {
+    FLOG("Failed to get curl version info!");
+  }
   if (!(curl_ver->features & CURL_VERSION_HTTP2)) {
     WLOG("HTTP/2 is not supported by current libcurl");
   }
-#ifdef CURL_VERSION_HTTP3
-  if (!(curl_ver->features & CURL_VERSION_HTTP3))
-  {
+  if (!(curl_ver->features & CURL_VERSION_HTTP3)) {
     WLOG("HTTP/3 is not supported by current libcurl");
   }
-#else
-  WLOG("HTTP/3 was not available at build time, it will not work at all");
-#endif
   if (!(curl_ver->features & CURL_VERSION_IPV6)) {
     WLOG("IPv6 is not supported by current libcurl");
   }

src/options.c

@@ -19,15 +19,6 @@ enum {
 DEFAULT_HTTP_VERSION = 2
 };
 
-
-const char * options_sw_version(void) {
-#ifdef SW_VERSION
-  return SW_VERSION;
-#else
-  return "2023.10.10-atLeast";  // update date sometimes, like 1-2 times a year
-#endif
-}
-
 void options_init(struct Options *opt) {
   opt->listen_addr = "127.0.0.1";
   opt->listen_port = 5053;
@@ -53,7 +44,7 @@ void options_init(struct Options *opt) {
   opt->flight_recorder_size = 0;
 }
 
-int options_parse_args(struct Options *opt, int argc, char **argv) {
+enum OptionsParseResult options_parse_args(struct Options *opt, int argc, char **argv) {
   int c = 0;
   while ((c = getopt(argc, argv, "a:c:p:du:g:b:i:4r:e:t:l:vxqm:s:C:F:hV")) != -1) {
     switch (c) {
@@ -105,7 +96,7 @@ int options_parse_args(struct Options *opt, int argc, char **argv) {
       } else {
         printf("HTTP version already set to: HTTP/%s\n",
                opt->use_http_version == 1 ? "1.1" : "3");
-        return -1;
+        return OPR_OPTION_ERROR;
       }
       break;
     case 'm':
@@ -120,38 +111,35 @@ int options_parse_args(struct Options *opt, int argc, char **argv) {
     case 'F': // Flight recorder size
       opt->flight_recorder_size = atoi(optarg);
       break;
-    case '?':
-      printf("Unknown option '-%c'\n", c);
-      // fallthrough
     case 'h':
-      return -1;
+      return OPR_HELP;
     case 'V': // version
-      printf("%s\n", options_sw_version());
-      exit(0);
+      return OPR_VERSION;
+    case '?':
     default:
-      printf("Unknown state!");
-      exit(EXIT_FAILURE);
+      return OPR_PARSING_ERROR;
     }
   }
+
   if (opt->user) {
     struct passwd *p = getpwnam(opt->user);
     if (!p || !p->pw_uid) {
       printf("Username (%s) invalid.\n", opt->user);
-      return -1;
+      return OPR_OPTION_ERROR;
     }
     opt->uid = p->pw_uid;
   }
   if (opt->group) {
     struct group *g = getgrnam(opt->group);
     if (!g || !g->gr_gid) {
       printf("Group (%s) invalid.\n", opt->group);
-      return -1;
+      return OPR_OPTION_ERROR;
     }
     opt->gid = g->gr_gid;
   }
   if (opt->dscp < 0 || opt->dscp >63) {
       printf("DSCP code (%d) invalid:[0-63]\n", opt->dscp);
-      return -1;
+      return OPR_OPTION_ERROR;
   }
   opt->dscp <<= 2;
   // Get noisy about bad security practices.
@@ -174,28 +162,28 @@ int options_parse_args(struct Options *opt, int argc, char **argv) {
       strncmp(opt->resolver_url, "https://", 8) != 0) {
     printf("Resolver prefix (%s) must be a https:// address.\n",
            opt->resolver_url);
-    return -1;
+    return OPR_OPTION_ERROR;
   }
   if (opt->bootstrap_dns_polling_interval < 5 ||
       opt->bootstrap_dns_polling_interval > 3600) {
     printf("DNS servers polling interval must be between 5 and 3600.\n");
-    return -1;
+    return OPR_OPTION_ERROR;
   }
   if (opt->max_idle_time < 0 ||
       opt->max_idle_time > 3600) {
     printf("Maximum idle time must be between 0 and 3600.\n");
-    return -1;
+    return OPR_OPTION_ERROR;
   }
   if (opt->stats_interval < 0 || opt->stats_interval > 3600) {
     printf("Statistic interval must be between 0 and 3600.\n");
-    return -1;
+    return OPR_OPTION_ERROR;
   }
   if (opt->flight_recorder_size != 0 &&
       (opt->flight_recorder_size < 100 || opt->flight_recorder_size > 100000)) {
     printf("Flight recorder limit must be between 100 and 100000.\n");
-    return -1;
+    return OPR_OPTION_ERROR;
   }
-  return 0;
+  return OPR_SUCCESS;
 }
 
 void options_show_usage(int __attribute__((unused)) argc, char **argv) {
@@ -254,7 +242,7 @@ void options_show_usage(int __attribute__((unused)) argc, char **argv) {
          "                         in memory and dumping them on fatal error or on SIGUSR2 signal.\n"
          "                         (Default: %u, Disabled: 0, Min: 100, Max: 100000)\n",
          defaults.flight_recorder_size);
-  printf("  -V                     Print version and exit.\n");
+  printf("  -V                     Print versions and exit.\n");
   printf("  -h                     Print help and exit.\n");
   options_cleanup(&defaults);
 }

src/options.h

@@ -59,12 +59,19 @@ struct Options {
 } __attribute__((aligned(128)));
 typedef struct Options options_t;
 
+enum OptionsParseResult {
+    OPR_SUCCESS,
+    OPR_HELP,
+    OPR_VERSION,
+    OPR_OPTION_ERROR,
+    OPR_PARSING_ERROR
+};
+
 #ifdef __cplusplus
 extern "C" {
 #endif
-const char * options_sw_version(void);
 void options_init(struct Options *opt);
-int options_parse_args(struct Options *opt, int argc, char **argv);
+enum OptionsParseResult options_parse_args(struct Options *opt, int argc, char **argv);
 void options_show_usage(int argc, char **argv);
 void options_cleanup(struct Options *opt);
 #ifdef __cplusplus