src/network/lookup.h

#ifndef LOOKUP_H
#define LOOKUP_H

#include <stdint.h>
#include <stddef.h>
#include <features.h>
#include <netinet/in.h>
#include <netdb.h>

struct aibuf {
	struct addrinfo ai;
	union sa {
		struct sockaddr_in sin;
		struct sockaddr_in6 sin6;
	} sa;
	volatile int lock[1];
	short slot, ref;
};

struct address {
	int family;
	unsigned scopeid;
	uint8_t addr[16];
	int sortkey;
};

struct service {
	uint16_t port;
	unsigned char proto, socktype;
};

#define MAXNS 3

struct resolvconf {
	struct address ns[MAXNS];
	unsigned nns, attempts, ndots;
	unsigned timeout;
};

/* The limit of 48 results is a non-sharp bound on the number of addresses
 * that can fit in one 512-byte DNS packet full of v4 results and a second
 * packet full of v6 results. Due to headers, the actual limit is lower. */
#define MAXADDRS 48
#define MAXSERVS 2

hidden int __lookup_serv(struct service buf[static MAXSERVS], const char *name, int proto, int socktype, int flags);
hidden int __lookup_name(struct address buf[static MAXADDRS], char canon[static 256], const char *name, int family, int flags);
hidden int __lookup_ipliteral(struct address buf[static 1], const char *name, int family);

hidden int __get_resolv_conf(struct resolvconf *, char *, size_t);
hidden int __res_msend_rc(int, const unsigned char *const *, const int *, unsigned char *const *, int *, int, const struct resolvconf *);

hidden int __dns_parse(const unsigned char *, int, int (*)(void *, int, const void *, int, const void *), void *);

#endif