curl 2025-02-05 (34cf9d54)

Code extracted from:

    https://github.com/curl/curl.git

at commit 34cf9d54a46598c44938aa7598820484d7af7133 (curl-8_12_0).

lib/httpsrr.c

@@ -0,0 +1,167 @@
+/***************************************************************************
+ *                                  _   _ ____  _
+ *  Project                     ___| | | |  _ \| |
+ *                             / __| | | | |_) | |
+ *                            | (__| |_| |  _ <| |___
+ *                             \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ * SPDX-License-Identifier: curl
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+#ifdef USE_HTTPSRR
+
+#include "urldata.h"
+#include "curl_addrinfo.h"
+#include "httpsrr.h"
+#include "connect.h"
+#include "sendf.h"
+
+/* The last 3 #include files should be in this order */
+#include "curl_printf.h"
+#include "curl_memory.h"
+#include "memdebug.h"
+
+CURLcode Curl_httpsrr_decode_alpn(const unsigned char *cp, size_t len,
+                                  unsigned char *alpns)
+{
+  /*
+   * spec here is as per RFC 9460, section-7.1.1
+   * encoding is a concatenated list of strings each preceded by a one
+   * octet length
+   * output is comma-sep list of the strings
+   * implementations may or may not handle quoting of comma within
+   * string values, so we might see a comma within the wire format
+   * version of a string, in which case we will precede that by a
+   * backslash - same goes for a backslash character, and of course
+   * we need to use two backslashes in strings when we mean one;-)
+   */
+  struct dynbuf dval;
+  int idnum = 0;
+
+  Curl_dyn_init(&dval, DYN_DOH_RESPONSE);
+  while(len > 0) {
+    size_t tlen = (size_t) *cp++;
+    size_t i;
+    enum alpnid id;
+    len--;
+    if(tlen > len)
+      goto err;
+    /* add escape char if needed, clunky but easier to read */
+    for(i = 0; i != tlen; i++) {
+      if('\\' == *cp || ',' == *cp) {
+        if(Curl_dyn_addn(&dval, "\\", 1))
+          goto err;
+      }
+      if(Curl_dyn_addn(&dval, cp++, 1))
+        goto err;
+    }
+    len -= tlen;
+
+    /* we only store ALPN ids we know about */
+    id = Curl_alpn2alpnid(Curl_dyn_ptr(&dval), Curl_dyn_len(&dval));
+    if(id != ALPN_none) {
+      if(idnum == MAX_HTTPSRR_ALPNS)
+        break;
+      alpns[idnum++] = (unsigned char)id;
+    }
+    Curl_dyn_reset(&dval);
+  }
+  Curl_dyn_free(&dval);
+  if(idnum < MAX_HTTPSRR_ALPNS)
+    alpns[idnum] = ALPN_none; /* terminate the list */
+  return CURLE_OK;
+err:
+  Curl_dyn_free(&dval);
+  return CURLE_BAD_CONTENT_ENCODING;
+}
+
+#ifdef USE_ARES
+
+static void httpsrr_opt(struct Curl_easy *data,
+                        const ares_dns_rr_t *rr,
+                        ares_dns_rr_key_t key, size_t idx)
+{
+  size_t len = 0;
+  const unsigned char *val = NULL;
+  unsigned short code;
+  struct thread_data *res = data->state.async.tdata;
+  struct Curl_https_rrinfo *hi = &res->hinfo;
+  code  = ares_dns_rr_get_opt(rr, key, idx, &val, &len);
+
+  switch(code) {
+  case HTTPS_RR_CODE_ALPN: /* str_list */
+    Curl_httpsrr_decode_alpn(val, len, hi->alpns);
+    infof(data, "HTTPS RR ALPN: %u %u %u %u",
+          hi->alpns[0], hi->alpns[1], hi->alpns[2], hi->alpns[3]);
+    break;
+  case HTTPS_RR_CODE_NO_DEF_ALPN:
+    infof(data, "HTTPS RR no-def-alpn");
+    break;
+  case HTTPS_RR_CODE_IPV4: /* addr4 list */
+    infof(data, "HTTPS RR IPv4");
+    break;
+  case HTTPS_RR_CODE_ECH:
+    infof(data, "HTTPS RR ECH");
+    break;
+  case HTTPS_RR_CODE_IPV6: /* addr6 list */
+    infof(data, "HTTPS RR IPv6");
+    break;
+  case HTTPS_RR_CODE_PORT:
+    infof(data, "HTTPS RR port");
+    break;
+  default:
+    infof(data, "HTTPS RR unknown code");
+    break;
+  }
+}
+
+void Curl_dnsrec_done_cb(void *arg, ares_status_t status,
+                         size_t timeouts,
+                         const ares_dns_record_t *dnsrec)
+{
+  struct Curl_easy *data = arg;
+  size_t i;
+#ifdef CURLRES_ARES
+  struct thread_data *res = data->state.async.tdata;
+
+  res->num_pending--;
+#endif
+  (void)timeouts;
+  if((ARES_SUCCESS != status) || !dnsrec)
+    return;
+
+  for(i = 0; i < ares_dns_record_rr_cnt(dnsrec, ARES_SECTION_ANSWER); i++) {
+    size_t opt;
+    const ares_dns_rr_t *rr =
+      ares_dns_record_rr_get_const(dnsrec, ARES_SECTION_ANSWER, i);
+    if(ares_dns_rr_get_type(rr) != ARES_REC_TYPE_HTTPS)
+      continue;
+    /* When SvcPriority is 0, the SVCB record is in AliasMode. Otherwise, it
+       is in ServiceMode */
+    infof(data, "HTTPS RR priority: %u",
+          ares_dns_rr_get_u16(rr, ARES_RR_HTTPS_PRIORITY));
+    for(opt = 0; opt < ares_dns_rr_get_opt_cnt(rr, ARES_RR_HTTPS_PARAMS);
+        opt++)
+      httpsrr_opt(data, rr, ARES_RR_HTTPS_PARAMS, opt);
+  }
+}
+
+#endif /* USE_ARES */
+
+#endif /* USE_HTTPSRR */