Zephyr API Documentation 3.7.99
A Scalable Open Source RTOS
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DNS resolving library . More...
Data Structures | |
struct | dns_addrinfo |
Address info struct is passed to callback that gets all the results. More... | |
struct | dns_resolve_context |
DNS resolve context structure. More... | |
Macros | |
#define | DNS_MAX_NAME_SIZE 20 |
Max size of the resolved name. | |
Typedefs | |
typedef void(* | dns_resolve_cb_t) (enum dns_resolve_status status, struct dns_addrinfo *info, void *user_data) |
DNS resolve callback. | |
Enumerations | |
enum | dns_query_type { DNS_QUERY_TYPE_A = 1 , DNS_QUERY_TYPE_AAAA = 28 } |
DNS query type enum. More... | |
enum | dns_resolve_status { DNS_EAI_BADFLAGS = -1 , DNS_EAI_NONAME = -2 , DNS_EAI_AGAIN = -3 , DNS_EAI_FAIL = -4 , DNS_EAI_NODATA = -5 , DNS_EAI_FAMILY = -6 , DNS_EAI_SOCKTYPE = -7 , DNS_EAI_SERVICE = -8 , DNS_EAI_ADDRFAMILY = -9 , DNS_EAI_MEMORY = -10 , DNS_EAI_SYSTEM = -11 , DNS_EAI_OVERFLOW = -12 , DNS_EAI_INPROGRESS = -100 , DNS_EAI_CANCELED = -101 , DNS_EAI_NOTCANCELED = -102 , DNS_EAI_ALLDONE = -103 , DNS_EAI_IDN_ENCODE = -105 } |
Status values for the callback. More... | |
Functions | |
int | dns_resolve_init (struct dns_resolve_context *ctx, const char *dns_servers_str[], const struct sockaddr *dns_servers_sa[]) |
Init DNS resolving context. | |
int | dns_resolve_init_default (struct dns_resolve_context *ctx) |
Init DNS resolving context with default Kconfig options. | |
int | dns_resolve_close (struct dns_resolve_context *ctx) |
Close DNS resolving context. | |
int | dns_resolve_reconfigure (struct dns_resolve_context *ctx, const char *servers_str[], const struct sockaddr *servers_sa[]) |
Reconfigure DNS resolving context. | |
int | dns_resolve_cancel (struct dns_resolve_context *ctx, uint16_t dns_id) |
Cancel a pending DNS query. | |
int | dns_resolve_cancel_with_name (struct dns_resolve_context *ctx, uint16_t dns_id, const char *query_name, enum dns_query_type query_type) |
Cancel a pending DNS query using id, name and type. | |
int | dns_resolve_name (struct dns_resolve_context *ctx, const char *query, enum dns_query_type type, uint16_t *dns_id, dns_resolve_cb_t cb, void *user_data, int32_t timeout) |
Resolve DNS name. | |
struct dns_resolve_context * | dns_resolve_get_default (void) |
Get default DNS context. | |
static int | dns_get_addr_info (const char *query, enum dns_query_type type, uint16_t *dns_id, dns_resolve_cb_t cb, void *user_data, int32_t timeout) |
Get IP address info from DNS. | |
static int | dns_cancel_addr_info (uint16_t dns_id) |
Cancel a pending DNS query. | |
DNS resolving library .
#define DNS_MAX_NAME_SIZE 20 |
#include <zephyr/net/dns_resolve.h>
Max size of the resolved name.
typedef void(* dns_resolve_cb_t) (enum dns_resolve_status status, struct dns_addrinfo *info, void *user_data) |
#include <zephyr/net/dns_resolve.h>
DNS resolve callback.
The DNS resolve callback is called after a successful DNS resolving. The resolver can call this callback multiple times, one for each resolved address.
status | The status of the query: DNS_EAI_INPROGRESS returned for each resolved address DNS_EAI_ALLDONE mark end of the resolving, info is set to NULL in this case DNS_EAI_CANCELED if the query was canceled manually or timeout happened DNS_EAI_FAIL if the name cannot be resolved by the server DNS_EAI_NODATA if there is no such name other values means that an error happened. |
info | Query results are stored here. |
user_data | The user data given in dns_resolve_name() call. |
enum dns_query_type |
#include <zephyr/net/dns_resolve.h>
DNS query type enum.
Enumerator | |
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DNS_QUERY_TYPE_A | IPv4 query. |
DNS_QUERY_TYPE_AAAA | IPv6 query. |
enum dns_resolve_status |
#include <zephyr/net/dns_resolve.h>
Status values for the callback.
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inlinestatic |
#include <zephyr/net/dns_resolve.h>
Cancel a pending DNS query.
This releases DNS resources used by a pending query.
dns_id | DNS id of the pending query |
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inlinestatic |
#include <zephyr/net/dns_resolve.h>
Get IP address info from DNS.
This function can be used to resolve e.g., IPv4 or IPv6 address. Note that this is asynchronous call, the function will return immediately and system will call the callback after resolving has finished or timeout has occurred. We might send the query to multiple servers (if there are more than one server configured), but we only use the result of the first received response. This variant uses system wide DNS servers.
query | What the caller wants to resolve. |
type | What kind of data the caller wants to get. |
dns_id | DNS id is returned to the caller. This is needed if one wishes to cancel the query. This can be set to NULL if there is no need to cancel the query. |
cb | Callback to call after the resolving has finished or timeout has happened. |
user_data | The user data. |
timeout | The timeout value for the connection. Possible values: SYS_FOREVER_MS: the query is tried forever, user needs to cancel it manually if it takes too long time to finish >0: start the query and let the system timeout it after specified ms |
int dns_resolve_cancel | ( | struct dns_resolve_context * | ctx, |
uint16_t | dns_id ) |
#include <zephyr/net/dns_resolve.h>
Cancel a pending DNS query.
This releases DNS resources used by a pending query.
ctx | DNS context |
dns_id | DNS id of the pending query |
int dns_resolve_cancel_with_name | ( | struct dns_resolve_context * | ctx, |
uint16_t | dns_id, | ||
const char * | query_name, | ||
enum dns_query_type | query_type ) |
#include <zephyr/net/dns_resolve.h>
Cancel a pending DNS query using id, name and type.
This releases DNS resources used by a pending query.
ctx | DNS context |
dns_id | DNS id of the pending query |
query_name | Name of the resource we are trying to query (hostname) |
query_type | Type of the query (A or AAAA) |
int dns_resolve_close | ( | struct dns_resolve_context * | ctx | ) |
#include <zephyr/net/dns_resolve.h>
Close DNS resolving context.
This releases DNS resolving context and marks the context unusable. Caller must call the dns_resolve_init() again to make context usable.
ctx | DNS context |
struct dns_resolve_context * dns_resolve_get_default | ( | void | ) |
#include <zephyr/net/dns_resolve.h>
Get default DNS context.
The system level DNS context uses DNS servers that are defined in project config file. If no DNS servers are defined by the user, then resolving DNS names using default DNS context will do nothing. The configuration options are described in subsys/net/lib/dns/Kconfig file.
int dns_resolve_init | ( | struct dns_resolve_context * | ctx, |
const char * | dns_servers_str[], | ||
const struct sockaddr * | dns_servers_sa[] ) |
#include <zephyr/net/dns_resolve.h>
Init DNS resolving context.
This function sets the DNS server address and initializes the DNS context that is used by the actual resolver. DNS server addresses can be specified either in textual form, or as struct sockaddr (or both). Note that the recommended way to resolve DNS names is to use the dns_get_addr_info() API. In that case user does not need to call dns_resolve_init() as the DNS servers are already setup by the system.
ctx | DNS context. If the context variable is allocated from the stack, then the variable needs to be valid for the whole duration of the resolving. Caller does not need to fill the variable beforehand or edit the context afterwards. |
dns_servers_str | DNS server addresses using textual strings. The array is NULL terminated. The port number can be given in the string. Syntax for the server addresses with or without port numbers: IPv4 : 10.0.9.1 IPv4 + port : 10.0.9.1:5353 IPv6 : 2001:db8::22:42 IPv6 + port : [2001:db8::22:42]:5353 |
dns_servers_sa | DNS server addresses as struct sockaddr. The array is NULL terminated. Port numbers are optional in struct sockaddr, the default will be used if set to 0. |
int dns_resolve_init_default | ( | struct dns_resolve_context * | ctx | ) |
#include <zephyr/net/dns_resolve.h>
Init DNS resolving context with default Kconfig options.
ctx | DNS context. |
int dns_resolve_name | ( | struct dns_resolve_context * | ctx, |
const char * | query, | ||
enum dns_query_type | type, | ||
uint16_t * | dns_id, | ||
dns_resolve_cb_t | cb, | ||
void * | user_data, | ||
int32_t | timeout ) |
#include <zephyr/net/dns_resolve.h>
Resolve DNS name.
This function can be used to resolve e.g., IPv4 or IPv6 address. Note that this is asynchronous call, the function will return immediately and system will call the callback after resolving has finished or timeout has occurred. We might send the query to multiple servers (if there are more than one server configured), but we only use the result of the first received response.
ctx | DNS context |
query | What the caller wants to resolve. |
type | What kind of data the caller wants to get. |
dns_id | DNS id is returned to the caller. This is needed if one wishes to cancel the query. This can be set to NULL if there is no need to cancel the query. |
cb | Callback to call after the resolving has finished or timeout has happened. |
user_data | The user data. |
timeout | The timeout value for the query. Possible values: SYS_FOREVER_MS: the query is tried forever, user needs to cancel it manually if it takes too long time to finish >0: start the query and let the system timeout it after specified ms |
int dns_resolve_reconfigure | ( | struct dns_resolve_context * | ctx, |
const char * | servers_str[], | ||
const struct sockaddr * | servers_sa[] ) |
#include <zephyr/net/dns_resolve.h>
Reconfigure DNS resolving context.
Reconfigures DNS context with new server list.
ctx | DNS context |
servers_str | DNS server addresses using textual strings. The array is NULL terminated. The port number can be given in the string. Syntax for the server addresses with or without port numbers: IPv4 : 10.0.9.1 IPv4 + port : 10.0.9.1:5353 IPv6 : 2001:db8::22:42 IPv6 + port : [2001:db8::22:42]:5353 |
servers_sa | DNS server addresses as struct sockaddr. The array is NULL terminated. Port numbers are optional in struct sockaddr, the default will be used if set to 0. |