picotcp/modules/pico_dns_common.c

23 #define dns_name_foreach_label_safe(label, name, next, maxlen) \
24     for ((label) = (name), (next) = (char *)((name) + *(unsigned char*)(name) + 1); \
25          (*(label) != '\0') && ((uint16_t)((label) - (name)) < (maxlen)); \
29  *  Checks if the DNS name doesn't exceed 256 bytes including zero-byte.
31  *  @param namelen Length of the DNS name-string including zero-byte
41  *  Returns the length of a name in a DNS-packet as if DNS name compression
44  *  @param name Compressed name you want the calculate the strlen from
45  *  @return Returns strlen of a compressed name, takes the first byte of compr-
50 pico_dns_namelen_comp( char *name )
56     if (!name) {
62     dns_name_foreach_label_safe(label, name, next, 255) {
68     len = (uint16_t)(label - name);
76  *  Returns the uncompressed name in DNS name format when DNS name compression
79  *  @param name   Compressed name, should be in the bounds of the actual packet
80  *  @param packet Packet that contains the compressed name
81  *  @return Returns the decompressed name, NULL on failure.
84 pico_dns_decompress_name( char *name, pico_dns_packet *packet )
95     iterator = (uint8_t *) name;
116     /* Provide storage for the name to return */
129  *  Determines the length of a given url as if it where a DNS name in reverse
132  *  @param url     URL wanted to create a reverse resolution name from.
137  *  @return Returns the length of the reverse name
167  *  Converts a DNS name in URL format to a reverse name in DNS name format.
168  *  Provides space for the DNS name as well. PICO_FREE() should be called on the
169  *  returned string buffer that contains the reverse DNS name.
171  *  @param url   DNS name in URL format to convert to reverse name
173  *  @return Returns a pointer to a string-buffer with the reverse DNS name.
188     /* Provide space for the reverse name */
219  *  Converts a DNS name in DNS name format to a name in URL format. Provides
220  *  space for the name in URL format as well. PICO_FREE() should be called on
221  *  the returned string buffer that contains the name in URL format.
223  *  @param qname DNS name in DNS name format to convert
224  *  @return Returns a pointer to a string-buffer with the URL name on success.
256  *  Converts a DNS name in URL format to a name in DNS name format. Provides
257  *  space for the DNS name as well. PICO_FREE() should be called on the returned
258  *  string buffer that contains the DNS name.
260  *  @param url DNS name in URL format to convert
261  *  @return Returns a pointer to a string-buffer with the DNS name on success.
301  *  Replaces .'s in a DNS name in URL format by the label lengths. So it
302  *  actually converts a name in URL format to a name in DNS name format.
305  *  @param url    Location to buffer with name in URL format. The URL needs to
337  *  Replaces the label lengths in a DNS-name by .'s. So it actually converts a
338  *  name in DNS format to a name in URL format.
341  *  @param ptr    Location to buffer with name in DNS name format
358  *  Determines the length of the first label of a DNS name in URL-format
360  *  @param url DNS name in URL-format
361  *  @return Length of the first label of DNS name in URL-format
541  *  Fills in the name of the DNS question.
543  *  @param qname   Pointer-pointer to the name-member of the DNS-question
544  *  @param url     Name in URL format you want to convert to a name in DNS name
550  *  @param proto   When reverse is true the reverse resolution name will be
553  *  @param reverse When this is true a reverse resolution name will be generated
555  *  @return The eventual length of the generated name, 0 on failure.
582  *  Creates a standalone DNS Question with a given name and type.
584  *  @param url     DNS question name in URL format. Will be converted to DNS
585  *				   name notation format.
591  *  @param reverse When this is true, a reverse resolution name will be
620     /* Fill name field */
641  *  Decompresses the name of a single DNS question.
643  *  @param question Question you want to decompress the name of
645  *  @return Pointer to original name of the DNS question before decompressing.
653     /* Try to decompress the question name */
852  *				   data should contain a DNS name, the name in the databuffer
855  *				   record should contain a DNS name, datalen needs to be
869     /* If type is PTR, rdata will be a DNS name in URL format */
895  *  Create a standalone DNS Resource Record with a given name.
897  *  @param url     DNS rrecord name in URL format. Will be converted to DNS
898  *                 name notation format.
900  *				   data should contain a DNS name, the name in the databuffer
903  *				   record should contain a DNS name, datalen needs to be
936     /* Provide space and convert the URL to a DNS name */
960  *  Decompresses the name of single DNS record.
962  *  @param record DNS record to decompress the name of.
964  *  @return Pointer to original name of the DNS record before decompressing.
972     /* Try to decompress the record name */
1079  *  Compares 2 DNS records by type and name only
1083  *  @return 0 when name and type of records are equal, returns difference when
1114  *  Compares 2 DNS records by type, name AND rdata for a truly unique result
1134     /* Compare type and name */
1236  *  Deletes all the questions with given DNS name from a pico_tree
1239  *  @param name  Name of the questions you want to delete
1244                          const char *name )
1250     if (!qtree || !name) {
1255     /* Iterate over tree and delete every node with given name */
1258         if ((question) && (strcasecmp(question->qname, name) == 0)) {
1268  *  Checks whether a question with given name is in the tree or not.
1271  *  @param name  Name you want to check for
1272  *  @return 1 when the name is present in the qtree, 0 when it's not.
1276                           const char *name )
1282     if (!qtree || !name) {
1290         if ((question) && (strcasecmp(question->qname, name) == 0))
1442             /* Copy the name */
1460  *  Looks for a name somewhere else in packet, more specifically between the
1461  *  beginning of the data buffer and the name itself.
1464 pico_dns_packet_compress_find_ptr( uint8_t *name,
1471     if (!name || !data || !len)
1474     if ((name < data) || (name > (data + len)))
1479     /* Iterate from the beginning of data up until the name-ptr */
1480     while (iterator < name) {
1481         /* Compare in each iteration of current name is equal to a section of
1483         if (memcmp((void *)iterator++, (void *)name,
1484                    pico_dns_strlen((char *)name) + 1u) == 0)
1491  *  Compresses a single name by looking for the same name somewhere else in the
1495 pico_dns_packet_compress_name( uint8_t *name,
1509     if (!name || !packet || !len) {
1514     if ((name < packet) || (name > (packet + *len))) {
1515         dns_dbg("Name ptr OOB. name: %p max: %p\n", name, packet + *len);
1520     /* Try to compress name */
1521     lbl_iterator = name;
1523         /* Try to find a compression pointer with current name */
1526         /* If name can be compressed */
1596  *  Applies DNS name compression to an entire DNS packet