dns_test.h File Reference

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Data Structures
struct	ast_dns_test_string
	Representation of a string in DNS. More...

Typedefs
typedef int(*	record_fn) (void *record, char *buf)
	Callback to write specific DNS record to an answer. More...

Functions
int	ast_dns_test_generate_result (struct ast_dns_query *query, void *records, size_t num_records, size_t record_size, record_fn generate, char *buffer)
	Generate a full DNS response for the given DNS records. More...
int	ast_dns_test_write_domain (const char *string, char *buf)
	Write a DNS domain to a buffer. More...
int	ast_dns_test_write_string (const struct ast_dns_test_string *string, char *buf)
	Write a DNS string to a buffer. More...

Typedef Documentation

record_fn

typedef int(* record_fn) (void *record, char *buf)

Callback to write specific DNS record to an answer.

When generating a DNS result, the type of DNS record being generated will need to be performed by individual test cases. This is a callback that tests can define to write a specific type of DNS record to the provided buffer.

There is no buffer size passed to this function. Tests are expected to use a buffer that is sufficiently large for their tests.

Parameters

record	Pointer to test-specific DNS record data
buf	The buffer into which to write the DNS record

Returns

The number of bytes written to the buffer

Definition at line 85 of file dns_test.h.

Function Documentation

ast_dns_test_generate_result()

int ast_dns_test_generate_result	(	struct ast_dns_query *	query,
		void *	records,
		size_t	num_records,
		size_t	record_size,
		record_fn	generate,
		char *	buffer
	)

Generate a full DNS response for the given DNS records.

This function takes care of generating the DNS header, question, and answer sections of a DNS response. In order to place test-specific record data into the DNS answers, a callback is provided as a parameter to this function so that the necessary records can be encoded properly by the tests.

There is no buffer size passed to this function. Tests are expected to use a buffer that is sufficiently large for their tests.

Parameters

query	The DNS query that is being processed
records	An array of test-specific representations of DNS records
num_records	The number of elements in the records array
record_size	The size of each element in the records array
generate	The test-specific encoder for DNS records
buffer	The buffer into which to write the DNS response

Definition at line 222 of file dns_test.c.

References ast_dns_test_write_domain(), ast_dns_test_write_string(), buf, generate_dns_answer(), generate_dns_header(), generate_dns_question(), and records.

Referenced by naptr_thread(), and srv_thread().

{
   char *ptr = buffer;
   char *record_iter;

   ptr += generate_dns_header(num_records, ptr);
   ptr += generate_dns_question(ptr);

   for (record_iter = records; record_iter < (char *) records + num_records * record_size; record_iter += record_size) {
      unsigned short rdlength;
      unsigned short net_rdlength;

      /* XXX Do we even want to override TTL? */
      ptr += generate_dns_answer(0, ptr);
      rdlength = generate(record_iter, ptr + 2);
      net_rdlength = htons(rdlength);
      memcpy(ptr, &net_rdlength, 2);
      ptr += 2;
      ptr += rdlength;
   }

   return ptr - buffer;
}

ast_dns_test_write_domain()

int ast_dns_test_write_domain	(	const char *	string,
		char *	buf
	)

Write a DNS domain to a buffer.

A DNS domain consists of a series of labels separated by dots. Each of these labels gets written as a DNS string. A DNS domain ends with a NULL label, which is essentially a zero-length DNS string.

There is no buffer size passed to this function. Tests are expected to use a buffer that is sufficiently large for their tests.

Parameters

string	The DNS domain to write
buf	The buffer to write the domain into

Returns

The number of bytes written to the buffer

A DNS domain consists of a series of labels separated by dots. Each of these labels gets written as a DNS string. A DNS domain ends with a NULL label, which is essentially a zero-length DNS string.

There is no buffer size passed to this function since we provide the data ourselves and have sized the buffer to be way larger than necessary for the tests.

Parameters

string	The DNS domain to write
buf	The buffer to write the domain into

Returns

The number of bytes written to the buffer

Definition at line 196 of file dns_test.c.

References ast_dns_test_write_string(), ast_strdupa, ast_strlen_zero, buf, copy(), ast_dns_test_string::len, strsep(), and ast_dns_test_string::val.

Referenced by ast_dns_test_generate_result(), generate_naptr_record(), and generate_srv_record().

{
   char *copy = ast_strdupa(string);
   char *part;
   char *ptr = buf;
   static const struct ast_dns_test_string null_label = {
      .len = 0,
      .val = "",
   };

   while (1) {
      struct ast_dns_test_string dns_str;
      part = strsep(&copy, ".");
      if (ast_strlen_zero(part)) {
         break;
      }
      dns_str.len = strlen(part);
      dns_str.val = part;

      ptr += ast_dns_test_write_string(&dns_str, ptr);
   }
   ptr += ast_dns_test_write_string(&null_label, ptr);

   return ptr - buf;
}

ast_dns_test_write_string()

int ast_dns_test_write_string	(	const struct ast_dns_test_string *	string,
		char *	buf
	)

Write a DNS string to a buffer.

This writes the DNS string to the buffer and returns the total number of bytes written to the buffer.

There is no buffer size passed to this function. Tests are expected to use a buffer that is sufficiently large for their tests.

Parameters

string	The string to write
buf	The buffer to write the string into

Returns

The number of bytes written to the buffer

This writes the DNS string to the buffer and returns the total number of bytes written to the buffer.

There is no buffer size passed to this function since we provide the data ourselves and have sized the buffer to be way larger than necessary for the tests.

Parameters

string	The string to write
buf	The buffer to write the string into

Returns

The number of bytes written to the buffer

Definition at line 162 of file dns_test.c.

References len(), and ast_dns_test_string::val.

Referenced by ast_dns_test_generate_result(), ast_dns_test_write_domain(), and generate_naptr_record().

{
   uint8_t len = string->len;
   size_t actual_len = strlen(string->val);
   buf[0] = len;
   /*
    * We use the actual length of the string instead of
    * the stated value since sometimes we're going to lie about
    * the length of the string
    */
   if (actual_len) {
      memcpy(&buf[1], string->val, strlen(string->val));
   }

   return actual_len + 1;
}