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/*
* Copyright (C) 2006-2009 Stig Venaas <venaas@uninett.no>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*/
#include <stdlib.h>
#include <string.h>
#include <netdb.h>
#include "debug.h"
#include "util.h"
#include "resolve.h"
void resolve_freehostport(struct hostportres *hp) {
if (hp) {
free(hp->host);
free(hp->port);
if (hp->addrinfo)
freeaddrinfo(hp->addrinfo);
free(hp);
}
}
static int resolve_parsehostport(struct hostportres *hp, char *hostport, char *default_port) {
char *p, *field;
int ipv6 = 0;
p = hostport;
/* allow literal addresses and port, e.g. [2001:db8::1]:1812 */
if (*p == '[') {
p++;
field = p;
for (; *p && *p != ']' && *p != ' ' && *p != '\t' && *p != '\n'; p++);
if (*p != ']') {
debug(DBG_ERR, "no ] matching initial [");
return 0;
}
ipv6 = 1;
} else {
field = p;
for (; *p && *p != ':' && *p != ' ' && *p != '\t' && *p != '\n'; p++);
}
if (field == p) {
debug(DBG_ERR, "missing host/address");
return 0;
}
hp->host = stringcopy(field, p - field);
if (ipv6) {
p++;
if (*p && *p != ':' && *p != ' ' && *p != '\t' && *p != '\n') {
debug(DBG_ERR, "unexpected character after ]");
return 0;
}
}
if (*p == ':') {
/* port number or service name is specified */;
field = ++p;
for (; *p && *p != ' ' && *p != '\t' && *p != '\n'; p++);
if (field == p) {
debug(DBG_ERR, "syntax error, : but no following port");
return 0;
}
hp->port = stringcopy(field, p - field);
} else
hp->port = default_port ? stringcopy(default_port, 0) : NULL;
return 1;
}
struct hostportres *resolve_newhostport(char *hostport, char *default_port, uint8_t prefixok) {
struct hostportres *hp;
char *slash, *s;
int plen;
hp = malloc(sizeof(struct hostportres));
if (!hp) {
debug(DBG_ERR, "resolve_newhostport: malloc failed");
goto errexit;
}
memset(hp, 0, sizeof(struct hostportres));
if (!resolve_parsehostport(hp, hostport, default_port))
goto errexit;
if (!strcmp(hp->host, "*")) {
free(hp->host);
hp->host = NULL;
}
slash = hp->host ? strchr(hp->host, '/') : NULL;
if (slash) {
if (!prefixok) {
debug(DBG_WARN, "resolve_newhostport: prefix not allowed here", hp->host);
goto errexit;
}
s = slash + 1;
if (!*s) {
debug(DBG_WARN, "resolve_newhostport: prefix length must be specified after the / in %s", hp->host);
goto errexit;
}
for (; *s; s++)
if (*s < '0' || *s > '9') {
debug(DBG_WARN, "resolve_newhostport: %s in %s is not a valid prefix length", slash + 1, hp->host);
goto errexit;
}
plen = atoi(slash + 1);
if (plen < 0 || plen > 128) {
debug(DBG_WARN, "resolve_newhostport: %s in %s is not a valid prefix length", slash + 1, hp->host);
goto errexit;
}
hp->prefixlen = plen;
*slash = '\0';
} else
hp->prefixlen = 255;
return hp;
errexit:
resolve_freehostport(hp);
return NULL;
}
static int resolve_resolve(struct hostportres *hp, int socktype, uint8_t passive) {
struct addrinfo hints, *res;
memset(&hints, 0, sizeof(hints));
hints.ai_socktype = socktype;
hints.ai_family = AF_UNSPEC;
if (passive)
hints.ai_flags = AI_PASSIVE;
if (!hp->host && !hp->port) {
/* getaddrinfo() doesn't like host and port to be NULL */
if (getaddrinfo(hp->host, "1812" /* can be anything */, &hints, &hp->addrinfo)) {
debug(DBG_WARN, "resolve_resolve: can't resolve (null) port (null)");
goto errexit;
}
for (res = hp->addrinfo; res; res = res->ai_next)
port_set(res->ai_addr, 0);
} else {
if (hp->prefixlen != 255)
hints.ai_flags |= AI_NUMERICHOST;
if (getaddrinfo(hp->host, hp->port, &hints, &hp->addrinfo)) {
debug(DBG_WARN, "resolve_resolve: can't resolve %s port %s", hp->host ? hp->host : "(null)", hp->port ? hp->port : "(null)");
goto errexit;
}
if (hp->prefixlen != 255) {
switch (hp->addrinfo->ai_family) {
case AF_INET:
if (hp->prefixlen > 32) {
debug(DBG_WARN, "resolve_resolve: prefix length must be <= 32 in %s", hp->host);
goto errexit;
}
break;
case AF_INET6:
break;
default:
debug(DBG_WARN, "resolve_resolve: prefix must be IPv4 or IPv6 in %s", hp->host);
goto errexit;
}
}
}
return 1;
errexit:
if (hp->addrinfo)
freeaddrinfo(hp->addrinfo);
return 0;
}
int resolve_hostports(struct list *hostports, int socktype) {
struct list_node *entry;
struct hostportres *hp;
for (entry = list_first(hostports); entry; entry = list_next(entry)) {
hp = (struct hostportres *)entry->data;
if (!hp->addrinfo && !resolve_resolve(hp, socktype, 0))
return 0;
}
return 1;
}
struct addrinfo *resolve_passiveaddrinfo(char *hostport, char *default_port, int socktype) {
struct addrinfo *ai = NULL;
struct hostportres *hp = resolve_newhostport(hostport, default_port, 0);
if (hp && resolve_resolve(hp, socktype, 1)) {
ai = hp->addrinfo;
hp->addrinfo = NULL;
}
resolve_freehostport(hp);
return ai;
}
/* returns 1 if the len first bits are equal, else 0 */
static int prefixmatch(void *a1, void *a2, uint8_t len) {
static uint8_t mask[] = { 0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe };
uint8_t r, l = len / 8;
if (l && memcmp(a1, a2, l))
return 0;
r = len % 8;
if (!r)
return 1;
return (((uint8_t *)a1)[l] & mask[r]) == (((uint8_t *)a2)[l] & mask[r]);
}
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