ADDRINFO_DNS_SERVER structure (ws2def.h)

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Represents a custom Domain Name System (DNS) server, used in the Winsock APIs.

Syntax

typedef struct addrinfo_dns_server {
  unsigned int     ai_servertype;
  unsigned __int64 ai_flags;
  unsigned int     ai_addrlen;
  struct sockaddr  *ai_addr;
  union {
    PWSTR ai_template;
  };
} ADDRINFO_DNS_SERVER;

Members

ai_servertype

The type of DNS server. Can be one of the following values.

Constant Value Meaning
AI_DNS_SERVER_TYPE_UDP 1 A regular DNS server.
AI_DNS_SERVER_TYPE_DOH 2 A DNS-over-HTTPS server.

ai_flags

A bitmap containing any of the following options.

Constant Value Meaning
AI_DNS_SERVER_UDP_FALLBACK 0x1 This server can also be used for non-secure name resolution.

ai_addrlen

The length in bytes of the socket address structure that ai_addr points to.

ai_addr

A pointer to a socket address structure containing the address of the custom server. Only SOCKADDR_IN and SOCKADDR_IN6 structures are supported. The sa_family member must be set to AF_INET or AF_INET6. The rest of the structure must be zeroed out, with the exception of the SOCKADDR_IN::sin_addr member for IPv4, or SOCKADDR_IN6::sin6_addr for IPv6.

ai_template

If ai_servertype is set to AI_DNS_SERVER_TYPE_DOH, then this member must point to a NULL-terminated wide string representing the DNS-over-HTTPS template for this server.

If ai_servertype is set to AI_DNS_SERVER_TYPE_UDP, then this field must be NULL.

Requirements

Requirement Value
Minimum supported client Windows Build 22000
Minimum supported server Windows Build 22000
Header ws2def.h

See also