quickjs-tart

ares_dns_multistring.c (7825B)

---

 /* MIT License
  *
  * Copyright (c) 2024 Brad House
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice (including the next
  * paragraph) shall be included in all copies or substantial portions of the
  * Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE.
  *
  * SPDX-License-Identifier: MIT
  */
 #include "ares_private.h"
 #include "ares_dns_private.h"
 
 typedef struct {
   unsigned char *data;
   size_t         len;
 } multistring_data_t;
 
 struct ares_dns_multistring {
   /*! whether or not cached concatenated string is valid */
   ares_bool_t    cache_invalidated;
   /*! combined/concatenated string cache */
   unsigned char *cache_str;
   /*! length of combined/concatenated string */
   size_t         cache_str_len;
   /*! Data making up strings */
   ares_array_t  *strs; /*!< multistring_data_t type */
 };
 
 static void ares_dns_multistring_free_cb(void *arg)
 {
   multistring_data_t *data = arg;
   if (data == NULL) {
     return;
   }
   ares_free(data->data);
 }
 
 ares_dns_multistring_t *ares_dns_multistring_create(void)
 {
   ares_dns_multistring_t *strs = ares_malloc_zero(sizeof(*strs));
   if (strs == NULL) {
     return NULL;
   }
 
   strs->strs =
     ares_array_create(sizeof(multistring_data_t), ares_dns_multistring_free_cb);
   if (strs->strs == NULL) {
     ares_free(strs);
     return NULL;
   }
 
   return strs;
 }
 
 void ares_dns_multistring_clear(ares_dns_multistring_t *strs)
 {
   if (strs == NULL) {
     return;
   }
 
   while (ares_array_len(strs->strs)) {
     ares_array_remove_last(strs->strs);
   }
 }
 
 void ares_dns_multistring_destroy(ares_dns_multistring_t *strs)
 {
   if (strs == NULL) {
     return;
   }
   ares_dns_multistring_clear(strs);
   ares_array_destroy(strs->strs);
   ares_free(strs->cache_str);
   ares_free(strs);
 }
 
 ares_status_t ares_dns_multistring_swap_own(ares_dns_multistring_t *strs,
                                             size_t idx, unsigned char *str,
                                             size_t len)
 {
   multistring_data_t *data;
 
   if (strs == NULL || str == NULL || len == 0) {
     return ARES_EFORMERR;
   }
 
   strs->cache_invalidated = ARES_TRUE;
 
   data = ares_array_at(strs->strs, idx);
   if (data == NULL) {
     return ARES_EFORMERR;
   }
 
   ares_free(data->data);
   data->data = str;
   data->len  = len;
   return ARES_SUCCESS;
 }
 
 ares_status_t ares_dns_multistring_del(ares_dns_multistring_t *strs, size_t idx)
 {
   if (strs == NULL) {
     return ARES_EFORMERR;
   }
 
   strs->cache_invalidated = ARES_TRUE;
 
   return ares_array_remove_at(strs->strs, idx);
 }
 
 ares_status_t ares_dns_multistring_add_own(ares_dns_multistring_t *strs,
                                            unsigned char *str, size_t len)
 {
   multistring_data_t *data;
   ares_status_t       status;
 
   if (strs == NULL) {
     return ARES_EFORMERR;
   }
 
   strs->cache_invalidated = ARES_TRUE;
 
   /* NOTE: its ok to have an empty string added */
   if (str == NULL && len != 0) {
     return ARES_EFORMERR;
   }
 
   status = ares_array_insert_last((void **)&data, strs->strs);
   if (status != ARES_SUCCESS) {
     return status;
   }
 
   /* Issue #921, ares_dns_multistring_get() doesn't have a way to indicate
    * success or fail on a zero-length string which is actually valid.  So we
    * are going to allocate a 1-byte buffer to use as a placeholder in this
    * case */
   if (str == NULL) {
     str = ares_malloc_zero(1);
     if (str == NULL) {
       ares_array_remove_last(strs->strs);
       return ARES_ENOMEM;
     }
   }
 
   data->data = str;
   data->len  = len;
 
   return ARES_SUCCESS;
 }
 
 size_t ares_dns_multistring_cnt(const ares_dns_multistring_t *strs)
 {
   if (strs == NULL) {
     return 0;
   }
   return ares_array_len(strs->strs);
 }
 
 const unsigned char *
   ares_dns_multistring_get(const ares_dns_multistring_t *strs, size_t idx,
                            size_t *len)
 {
   const multistring_data_t *data;
 
   if (strs == NULL || len == NULL) {
     return NULL;
   }
 
   data = ares_array_at_const(strs->strs, idx);
   if (data == NULL) {
     return NULL;
   }
 
   *len = data->len;
   return data->data;
 }
 
 const unsigned char *ares_dns_multistring_combined(ares_dns_multistring_t *strs,
                                                    size_t                 *len)
 {
   ares_buf_t *buf = NULL;
   size_t      i;
 
   if (strs == NULL || len == NULL) {
     return NULL;
   }
 
   *len = 0;
 
   /* Return cache if possible */
   if (!strs->cache_invalidated) {
     *len = strs->cache_str_len;
     return strs->cache_str;
   }
 
   /* Clear cache */
   ares_free(strs->cache_str);
   strs->cache_str     = NULL;
   strs->cache_str_len = 0;
 
   buf = ares_buf_create();
 
   for (i = 0; i < ares_array_len(strs->strs); i++) {
     const multistring_data_t *data = ares_array_at_const(strs->strs, i);
     if (data == NULL ||
         ares_buf_append(buf, data->data, data->len) != ARES_SUCCESS) {
       ares_buf_destroy(buf);
       return NULL;
     }
   }
 
   strs->cache_str =
     (unsigned char *)ares_buf_finish_str(buf, &strs->cache_str_len);
   if (strs->cache_str != NULL) {
     strs->cache_invalidated = ARES_FALSE;
   }
   *len = strs->cache_str_len;
   return strs->cache_str;
 }
 
 ares_status_t ares_dns_multistring_parse_buf(ares_buf_t *buf,
                                              size_t      remaining_len,
                                              ares_dns_multistring_t **strs,
                                              ares_bool_t validate_printable)
 {
   unsigned char len;
   ares_status_t status   = ARES_EBADRESP;
   size_t        orig_len = ares_buf_len(buf);
 
   if (buf == NULL) {
     return ARES_EFORMERR;
   }
 
   if (remaining_len == 0) {
     return ARES_EBADRESP;
   }
 
   if (strs != NULL) {
     *strs = ares_dns_multistring_create();
     if (*strs == NULL) {
       return ARES_ENOMEM;
     }
   }
 
   while (orig_len - ares_buf_len(buf) < remaining_len) {
     status = ares_buf_fetch_bytes(buf, &len, 1);
     if (status != ARES_SUCCESS) {
       break; /* LCOV_EXCL_LINE: DefensiveCoding */
     }
 
 
     /* When used by the _str() parser, it really needs to be validated to
      * be a valid printable ascii string.  Do that here */
     if (len && validate_printable && ares_buf_len(buf) >= len) {
       size_t      mylen;
       const char *data = (const char *)ares_buf_peek(buf, &mylen);
       if (!ares_str_isprint(data, len)) {
         status = ARES_EBADSTR;
         break;
       }
     }
 
     if (strs != NULL) {
       unsigned char *data = NULL;
       if (len) {
         status = ares_buf_fetch_bytes_dup(buf, len, ARES_TRUE, &data);
         if (status != ARES_SUCCESS) {
           break;
         }
       }
       status = ares_dns_multistring_add_own(*strs, data, len);
       if (status != ARES_SUCCESS) {
         ares_free(data);
         break;
       }
     } else {
       status = ares_buf_consume(buf, len);
       if (status != ARES_SUCCESS) {
         break;
       }
     }
 
   }
 
   if (status != ARES_SUCCESS && strs != NULL) {
     ares_dns_multistring_destroy(*strs);
     *strs = NULL;
   }
 
   return status;
 }