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19c8da85d8
curl/ares/ares_init.c
Steinar H. Gunderson 23f5d145ec Previously, processing a large batch of timeouts was O(n^2) in the number of 
outstanding queries, and processing a DNS response packet was O(n) in the
number of outstanding queries. To speed things up in Google, we added a few circular,
doubly-linked lists of queries that are hash-bucketed based on
the attributes we care about, so most important operations are now O(1).

It might be that the number of buckets are higher than most people would need,
but on a quick calculation it should only be 100kB or so even on a 64-bit
system, so I've let it stay as-is.
2007-09-29 18:18:47 +00:00

1384 lines
37 KiB
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/* $Id$ */
/* Copyright 1998 by the Massachusetts Institute of Technology.
*
* Permission to use, copy, modify, and distribute this
* software and its documentation for any purpose and without
* fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright
* notice and this permission notice appear in supporting
* documentation, and that the name of M.I.T. not be used in
* advertising or publicity pertaining to distribution of the
* software without specific, written prior permission.
* M.I.T. makes no representations about the suitability of
* this software for any purpose. It is provided "as is"
* without express or implied warranty.
*/
#include "setup.h"
#if defined(WIN32) && !defined(WATT32)
#include "nameser.h"
#include <iphlpapi.h>
#include <malloc.h>
#else
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <arpa/nameser.h>
#ifdef HAVE_ARPA_NAMESER_COMPAT_H
#include <arpa/nameser_compat.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_PROCESS_H
#include <process.h> /* Some have getpid() here */
#endif
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <time.h>
#include <errno.h>
#include "ares.h"
#include "ares_private.h"
#include "inet_net_pton.h"
#ifdef WATT32
#undef WIN32 /* Redefined in MingW/MSVC headers */
#endif
static int init_by_options(ares_channel channel, const struct ares_options *options,
int optmask);
static int init_by_environment(ares_channel channel);
static int init_by_resolv_conf(ares_channel channel);
static int init_by_defaults(ares_channel channel);
static int config_nameserver(struct server_state **servers, int *nservers,
char *str);
static int set_search(ares_channel channel, const char *str);
static int set_options(ares_channel channel, const char *str);
static const char *try_option(const char *p, const char *q, const char *opt);
static void init_id_key(rc4_key* key,int key_data_len);
#ifndef WIN32
static int sortlist_alloc(struct apattern **sortlist, int *nsort, struct apattern *pat);
static int ip_addr(const char *s, int len, struct in_addr *addr);
static void natural_mask(struct apattern *pat);
static int config_domain(ares_channel channel, char *str);
static int config_lookup(ares_channel channel, const char *str,
const char *bindch, const char *filech);
static int config_sortlist(struct apattern **sortlist, int *nsort,
const char *str);
static char *try_config(char *s, const char *opt);
#endif
#define ARES_CONFIG_CHECK(x) (x->lookups && x->nsort > -1 && \
x->nservers > -1 && \
x->ndomains > -1 && \
x->ndots > -1 && x->timeout > -1 && \
x->tries > -1)
int ares_init(ares_channel *channelptr)
{
return ares_init_options(channelptr, NULL, 0);
}
int ares_init_options(ares_channel *channelptr, struct ares_options *options,
int optmask)
{
ares_channel channel;
int i;
int status = ARES_SUCCESS;
struct server_state *server;
struct timeval tv;
#ifdef CURLDEBUG
const char *env = getenv("CARES_MEMDEBUG");
if (env)
curl_memdebug(env);
env = getenv("CARES_MEMLIMIT");
if (env)
curl_memlimit(atoi(env));
#endif
channel = malloc(sizeof(struct ares_channeldata));
if (!channel) {
*channelptr = NULL;
return ARES_ENOMEM;
}
/* Set everything to distinguished values so we know they haven't
* been set yet.
*/
channel->flags = -1;
channel->timeout = -1;
channel->tries = -1;
channel->ndots = -1;
channel->udp_port = -1;
channel->tcp_port = -1;
channel->socket_send_buffer_size = -1;
channel->socket_receive_buffer_size = -1;
channel->nservers = -1;
channel->ndomains = -1;
channel->nsort = -1;
channel->tcp_connection_generation = 0;
channel->lookups = NULL;
channel->domains = NULL;
channel->sortlist = NULL;
channel->servers = NULL;
channel->sock_state_cb = NULL;
channel->sock_state_cb_data = NULL;
gettimeofday(&tv, NULL);
channel->last_timeout_processed = tv.tv_sec;
/* Initialize our lists of queries */
ares__init_list_head(&(channel->all_queries));
for (i = 0; i < ARES_QID_TABLE_SIZE; i++)
{
ares__init_list_head(&(channel->queries_by_qid[i]));
}
for (i = 0; i < ARES_TIMEOUT_TABLE_SIZE; i++)
{
ares__init_list_head(&(channel->queries_by_timeout[i]));
}
/* Initialize configuration by each of the four sources, from highest
* precedence to lowest.
*/
if (status == ARES_SUCCESS) {
status = init_by_options(channel, options, optmask);
if (status != ARES_SUCCESS)
DEBUGF(fprintf(stderr, "Error: init_by_options failed: %s\n",
ares_strerror(status)));
}
if (status == ARES_SUCCESS) {
status = init_by_environment(channel);
if (status != ARES_SUCCESS)
DEBUGF(fprintf(stderr, "Error: init_by_environment failed: %s\n",
ares_strerror(status)));
}
if (status == ARES_SUCCESS) {
status = init_by_resolv_conf(channel);
if (status != ARES_SUCCESS)
DEBUGF(fprintf(stderr, "Error: init_by_resolv_conf failed: %s\n",
ares_strerror(status)));
}
if (status == ARES_SUCCESS) {
status = init_by_defaults(channel);
if (status != ARES_SUCCESS)
DEBUGF(fprintf(stderr, "Error: init_by_defaults failed: %s\n",
ares_strerror(status)));
}
if (status != ARES_SUCCESS)
{
/* Something failed; clean up memory we may have allocated. */
if (channel->servers)
free(channel->servers);
if (channel->domains)
{
for (i = 0; i < channel->ndomains; i++)
free(channel->domains[i]);
free(channel->domains);
}
if (channel->sortlist)
free(channel->sortlist);
if(channel->lookups)
free(channel->lookups);
free(channel);
return status;
}
/* Trim to one server if ARES_FLAG_PRIMARY is set. */
if ((channel->flags & ARES_FLAG_PRIMARY) && channel->nservers > 1)
channel->nservers = 1;
/* Initialize server states. */
for (i = 0; i < channel->nservers; i++)
{
server = &channel->servers[i];
server->udp_socket = ARES_SOCKET_BAD;
server->tcp_socket = ARES_SOCKET_BAD;
server->tcp_connection_generation = ++channel->tcp_connection_generation;
server->tcp_lenbuf_pos = 0;
server->tcp_buffer = NULL;
server->qhead = NULL;
server->qtail = NULL;
ares__init_list_head(&(server->queries_to_server));
server->channel = channel;
server->is_broken = 0;
}
init_id_key(&channel->id_key, ARES_ID_KEY_LEN);
channel->next_id = ares__generate_new_id(&channel->id_key);
*channelptr = channel;
return ARES_SUCCESS;
}
/* Save options from initialized channel */
int ares_save_options(ares_channel channel, struct ares_options *options,
int *optmask)
{
int i;
/* Zero everything out */
memset(options, 0, sizeof(struct ares_options));
if (!ARES_CONFIG_CHECK(channel))
return ARES_ENODATA;
(*optmask) = (ARES_OPT_FLAGS|ARES_OPT_TIMEOUT|ARES_OPT_TRIES|ARES_OPT_NDOTS|
ARES_OPT_UDP_PORT|ARES_OPT_TCP_PORT|ARES_OPT_SOCK_STATE_CB|
ARES_OPT_SERVERS|ARES_OPT_DOMAINS|ARES_OPT_LOOKUPS|
ARES_OPT_SORTLIST);
/* Copy easy stuff */
options->flags = channel->flags;
options->timeout = channel->timeout;
options->tries = channel->tries;
options->ndots = channel->ndots;
options->udp_port = channel->udp_port;
options->tcp_port = channel->tcp_port;
options->sock_state_cb = channel->sock_state_cb;
options->sock_state_cb_data = channel->sock_state_cb_data;
/* Copy servers */
if (channel->nservers) {
options->servers =
malloc(channel->nservers * sizeof(struct server_state));
if (!options->servers && channel->nservers != 0)
return ARES_ENOMEM;
for (i = 0; i < channel->nservers; i++)
options->servers[i] = channel->servers[i].addr;
}
options->nservers = channel->nservers;
/* copy domains */
if (channel->ndomains) {
options->domains = malloc(channel->ndomains * sizeof(char *));
if (!options->domains)
return ARES_ENOMEM;
for (i = 0; i < channel->ndomains; i++)
{
options->ndomains = i;
options->domains[i] = strdup(channel->domains[i]);
if (!options->domains[i])
return ARES_ENOMEM;
}
}
options->ndomains = channel->ndomains;
/* copy lookups */
if (channel->lookups) {
options->lookups = strdup(channel->lookups);
if (!options->lookups && channel->lookups)
return ARES_ENOMEM;
}
/* copy sortlist */
if (channel->nsort) {
options->sortlist = malloc(channel->nsort * sizeof(struct apattern));
if (!options->sortlist)
return ARES_ENOMEM;
for (i = 0; i < channel->nsort; i++)
{
memcpy(&(options->sortlist[i]), &(channel->sortlist[i]),
sizeof(struct apattern));
}
}
options->nsort = channel->nsort;
return ARES_SUCCESS;
}
static int init_by_options(ares_channel channel,
const struct ares_options *options,
int optmask)
{
int i;
/* Easy stuff. */
if ((optmask & ARES_OPT_FLAGS) && channel->flags == -1)
channel->flags = options->flags;
if ((optmask & ARES_OPT_TIMEOUT) && channel->timeout == -1)
channel->timeout = options->timeout;
if ((optmask & ARES_OPT_TRIES) && channel->tries == -1)
channel->tries = options->tries;
if ((optmask & ARES_OPT_NDOTS) && channel->ndots == -1)
channel->ndots = options->ndots;
if ((optmask & ARES_OPT_UDP_PORT) && channel->udp_port == -1)
channel->udp_port = options->udp_port;
if ((optmask & ARES_OPT_TCP_PORT) && channel->tcp_port == -1)
channel->tcp_port = options->tcp_port;
if ((optmask & ARES_OPT_SOCK_STATE_CB) && channel->sock_state_cb == NULL)
{
channel->sock_state_cb = options->sock_state_cb;
channel->sock_state_cb_data = options->sock_state_cb_data;
}
if ((optmask & ARES_OPT_SOCK_SNDBUF)
&& channel->socket_send_buffer_size == -1)
channel->socket_send_buffer_size = options->socket_send_buffer_size;
if ((optmask & ARES_OPT_SOCK_RCVBUF)
&& channel->socket_receive_buffer_size == -1)
channel->socket_receive_buffer_size = options->socket_receive_buffer_size;
/* Copy the servers, if given. */
if ((optmask & ARES_OPT_SERVERS) && channel->nservers == -1)
{
/* Avoid zero size allocations at any cost */
if (options->nservers > 0)
{
channel->servers =
malloc(options->nservers * sizeof(struct server_state));
if (!channel->servers)
return ARES_ENOMEM;
for (i = 0; i < options->nservers; i++)
channel->servers[i].addr = options->servers[i];
}
channel->nservers = options->nservers;
}
/* Copy the domains, if given. Keep channel->ndomains consistent so
* we can clean up in case of error.
*/
if ((optmask & ARES_OPT_DOMAINS) && channel->ndomains == -1)
{
/* Avoid zero size allocations at any cost */
if (options->ndomains > 0)
{
channel->domains = malloc(options->ndomains * sizeof(char *));
if (!channel->domains)
return ARES_ENOMEM;
for (i = 0; i < options->ndomains; i++)
{
channel->ndomains = i;
channel->domains[i] = strdup(options->domains[i]);
if (!channel->domains[i])
return ARES_ENOMEM;
}
}
channel->ndomains = options->ndomains;
}
/* Set lookups, if given. */
if ((optmask & ARES_OPT_LOOKUPS) && !channel->lookups)
{
channel->lookups = strdup(options->lookups);
if (!channel->lookups)
return ARES_ENOMEM;
}
/* copy sortlist */
if ((optmask & ARES_OPT_SORTLIST) && channel->nsort == -1)
{
channel->sortlist = malloc(options->nsort * sizeof(struct apattern));
if (!channel->sortlist)
return ARES_ENOMEM;
for (i = 0; i < options->nsort; i++)
{
memcpy(&(channel->sortlist[i]), &(options->sortlist[i]), sizeof(struct apattern));
}
channel->nsort = options->nsort;
}
return ARES_SUCCESS;
}
static int init_by_environment(ares_channel channel)
{
const char *localdomain, *res_options;
int status;
localdomain = getenv("LOCALDOMAIN");
if (localdomain && channel->ndomains == -1)
{
status = set_search(channel, localdomain);
if (status != ARES_SUCCESS)
return status;
}
res_options = getenv("RES_OPTIONS");
if (res_options)
{
status = set_options(channel, res_options);
if (status != ARES_SUCCESS)
return status;
}
return ARES_SUCCESS;
}
#ifdef WIN32
/*
* Warning: returns a dynamically allocated buffer, the user MUST
* use free() if the function returns 1
*/
static int get_res_nt(HKEY hKey, const char *subkey, char **obuf)
{
/* Test for the size we need */
DWORD size = 0;
int result;
result = RegQueryValueEx(hKey, subkey, 0, NULL, NULL, &size);
if ((result != ERROR_SUCCESS && result != ERROR_MORE_DATA) || !size)
return 0;
*obuf = malloc(size+1);
if (!*obuf)
return 0;
if (RegQueryValueEx(hKey, subkey, 0, NULL,
(LPBYTE)*obuf, &size) != ERROR_SUCCESS)
{
free(*obuf);
return 0;
}
if (size == 1)
{
free(*obuf);
return 0;
}
return 1;
}
static int get_res_interfaces_nt(HKEY hKey, const char *subkey, char **obuf)
{
char enumbuf[39]; /* GUIDs are 38 chars + 1 for NULL */
DWORD enum_size = 39;
int idx = 0;
HKEY hVal;
while (RegEnumKeyEx(hKey, idx++, enumbuf, &enum_size, 0,
NULL, NULL, NULL) != ERROR_NO_MORE_ITEMS)
{
int rc;
enum_size = 39;
if (RegOpenKeyEx(hKey, enumbuf, 0, KEY_QUERY_VALUE, &hVal) !=
ERROR_SUCCESS)
continue;
rc = get_res_nt(hVal, subkey, obuf);
RegCloseKey(hVal);
if (rc)
return 1;
}
return 0;
}
static int get_iphlpapi_dns_info (char *ret_buf, size_t ret_size)
{
FIXED_INFO *fi = alloca (sizeof(*fi));
DWORD size = sizeof (*fi);
typedef DWORD (WINAPI* get_net_param_func) (FIXED_INFO*, DWORD*);
get_net_param_func GetNetworkParams; /* available only on Win-98/2000+ */
HMODULE handle;
IP_ADDR_STRING *ipAddr;
int i, count = 0;
int debug = 0;
size_t ip_size = sizeof("255.255.255.255,")-1;
size_t left = ret_size;
char *ret = ret_buf;
HRESULT res;
if (!fi)
return (0);
handle = LoadLibrary ("iphlpapi.dll");
if (!handle)
return (0);
GetNetworkParams = (get_net_param_func) GetProcAddress (handle, "GetNetworkParams");
if (!GetNetworkParams)
goto quit;
res = (*GetNetworkParams) (fi, &size);
if ((res != ERROR_BUFFER_OVERFLOW) && (res != ERROR_SUCCESS))
goto quit;
fi = alloca (size);
if (!fi || (*GetNetworkParams) (fi, &size) != ERROR_SUCCESS)
goto quit;
if (debug)
{
printf ("Host Name: %s\n", fi->HostName);
printf ("Domain Name: %s\n", fi->DomainName);
printf ("DNS Servers:\n"
" %s (primary)\n", fi->DnsServerList.IpAddress.String);
}
if (strlen(fi->DnsServerList.IpAddress.String) > 0 &&
inet_addr(fi->DnsServerList.IpAddress.String) != INADDR_NONE &&
left > ip_size)
{
ret += sprintf (ret, "%s,", fi->DnsServerList.IpAddress.String);
left -= ret - ret_buf;
count++;
}
for (i = 0, ipAddr = fi->DnsServerList.Next; ipAddr && left > ip_size;
ipAddr = ipAddr->Next, i++)
{
if (inet_addr(ipAddr->IpAddress.String) != INADDR_NONE)
{
ret += sprintf (ret, "%s,", ipAddr->IpAddress.String);
left -= ret - ret_buf;
count++;
}
if (debug)
printf (" %s (secondary %d)\n", ipAddr->IpAddress.String, i+1);
}
quit:
if (handle)
FreeLibrary (handle);
if (debug && left <= ip_size)
printf ("Too many nameservers. Truncating to %d addressess", count);
if (ret > ret_buf)
ret[-1] = '\0';
return (count);
}
#endif
static int init_by_resolv_conf(ares_channel channel)
{
char *line = NULL;
int status = -1, nservers = 0, nsort = 0;
struct server_state *servers = NULL;
struct apattern *sortlist = NULL;
#ifdef WIN32
/*
NameServer info via IPHLPAPI (IP helper API):
GetNetworkParams() should be the trusted source for this.
Available in Win-98/2000 and later. If that fail, fall-back to
registry information.
NameServer Registry:
On Windows 9X, the DNS server can be found in:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\VxD\MSTCP\NameServer
On Windows NT/2000/XP/2003:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\NameServer
or
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\DhcpNameServer
or
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\{AdapterID}\
NameServer
or
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\{AdapterID}\
DhcpNameServer
*/
HKEY mykey;
HKEY subkey;
DWORD data_type;
DWORD bytes;
DWORD result;
char buf[256];
if (channel->nservers > -1) /* don't override ARES_OPT_SERVER */
return ARES_SUCCESS;
if (get_iphlpapi_dns_info(buf,sizeof(buf)) > 0)
{
status = config_nameserver(&servers, &nservers, buf);
if (status == ARES_SUCCESS)
goto okay;
}
if (IS_NT())
{
if (RegOpenKeyEx(
HKEY_LOCAL_MACHINE, WIN_NS_NT_KEY, 0,
KEY_READ, &mykey
) == ERROR_SUCCESS)
{
RegOpenKeyEx(mykey, "Interfaces", 0,
KEY_QUERY_VALUE|KEY_ENUMERATE_SUB_KEYS, &subkey);
if (get_res_nt(mykey, NAMESERVER, &line))
{
status = config_nameserver(&servers, &nservers, line);
free(line);
}
else if (get_res_nt(mykey, DHCPNAMESERVER, &line))
{
status = config_nameserver(&servers, &nservers, line);
free(line);
}
/* Try the interfaces */
else if (get_res_interfaces_nt(subkey, NAMESERVER, &line))
{
status = config_nameserver(&servers, &nservers, line);
free(line);
}
else if (get_res_interfaces_nt(subkey, DHCPNAMESERVER, &line))
{
status = config_nameserver(&servers, &nservers, line);
free(line);
}
RegCloseKey(subkey);
RegCloseKey(mykey);
}
}
else
{
if (RegOpenKeyEx(
HKEY_LOCAL_MACHINE, WIN_NS_9X, 0,
KEY_READ, &mykey
) == ERROR_SUCCESS)
{
if ((result = RegQueryValueEx(
mykey, NAMESERVER, NULL, &data_type,
NULL, &bytes
)
) == ERROR_SUCCESS ||
result == ERROR_MORE_DATA)
{
if (bytes)
{
line = (char *)malloc(bytes+1);
if (RegQueryValueEx(mykey, NAMESERVER, NULL, &data_type,
(unsigned char *)line, &bytes) ==
ERROR_SUCCESS)
{
status = config_nameserver(&servers, &nservers, line);
}
free(line);
}
}
}
RegCloseKey(mykey);
}
if (status == ARES_SUCCESS)
status = ARES_EOF;
else
/* Catch the case when all the above checks fail (which happens when there
is no network card or the cable is unplugged) */
status = ARES_EFILE;
#elif defined(__riscos__)
/* Under RISC OS, name servers are listed in the
system variable Inet$Resolvers, space separated. */
line = getenv("Inet$Resolvers");
status = ARES_EOF;
if (line) {
char *resolvers = strdup(line), *pos, *space;
if (!resolvers)
return ARES_ENOMEM;
pos = resolvers;
do {
space = strchr(pos, ' ');
if (space)
*space = '\0';
status = config_nameserver(&servers, &nservers, pos);
if (status != ARES_SUCCESS)
break;
pos = space + 1;
} while (space);
if (status == ARES_SUCCESS)
status = ARES_EOF;
free(resolvers);
}
#elif defined(WATT32)
int i;
sock_init();
for (i = 0; def_nameservers[i]; i++)
;
if (i == 0)
return ARES_SUCCESS; /* use localhost DNS server */
nservers = i;
servers = calloc(sizeof(*servers), i);
if (!servers)
return ARES_ENOMEM;
for (i = 0; def_nameservers[i]; i++)
servers[i].addr.s_addr = htonl(def_nameservers[i]);
status = ARES_EOF;
#else
{
char *p;
FILE *fp;
int linesize;
int error;
/* Don't read resolv.conf and friends if we don't have to */
if (ARES_CONFIG_CHECK(channel))
return ARES_SUCCESS;
fp = fopen(PATH_RESOLV_CONF, "r");
if (fp) {
while ((status = ares__read_line(fp, &line, &linesize)) == ARES_SUCCESS)
{
if ((p = try_config(line, "domain")) && channel->ndomains == -1)
status = config_domain(channel, p);
else if ((p = try_config(line, "lookup")) && !channel->lookups)
status = config_lookup(channel, p, "bind", "file");
else if ((p = try_config(line, "search")) && channel->ndomains == -1)
status = set_search(channel, p);
else if ((p = try_config(line, "nameserver")) && channel->nservers == -1)
status = config_nameserver(&servers, &nservers, p);
else if ((p = try_config(line, "sortlist")) && channel->nsort == -1)
status = config_sortlist(&sortlist, &nsort, p);
else if ((p = try_config(line, "options")))
status = set_options(channel, p);
else
status = ARES_SUCCESS;
if (status != ARES_SUCCESS)
break;
}
fclose(fp);
}
else {
error = ERRNO;
switch(error) {
case ENOENT:
case ESRCH:
status = ARES_EOF;
break;
default:
DEBUGF(fprintf(stderr, "fopen() failed with error: %d %s\n",
error, strerror(error)));
DEBUGF(fprintf(stderr, "Error opening file: %s\n", PATH_RESOLV_CONF));
status = ARES_EFILE;
}
}
if ((status == ARES_EOF) && (!channel->lookups)) {
/* Many systems (Solaris, Linux, BSD's) use nsswitch.conf */
fp = fopen("/etc/nsswitch.conf", "r");
if (fp) {
while ((status = ares__read_line(fp, &line, &linesize)) == ARES_SUCCESS)
{
if ((p = try_config(line, "hosts:")) && !channel->lookups)
status = config_lookup(channel, p, "dns", "files");
}
fclose(fp);
}
else {
error = ERRNO;
switch(error) {
case ENOENT:
case ESRCH:
status = ARES_EOF;
break;
default:
DEBUGF(fprintf(stderr, "fopen() failed with error: %d %s\n",
error, strerror(error)));
DEBUGF(fprintf(stderr, "Error opening file: %s\n", "/etc/nsswitch.conf"));
status = ARES_EFILE;
}
}
}
if ((status == ARES_EOF) && (!channel->lookups)) {
/* Linux / GNU libc 2.x and possibly others have host.conf */
fp = fopen("/etc/host.conf", "r");
if (fp) {
while ((status = ares__read_line(fp, &line, &linesize)) == ARES_SUCCESS)
{
if ((p = try_config(line, "order")) && !channel->lookups)
status = config_lookup(channel, p, "bind", "hosts");
}
fclose(fp);
}
else {
error = ERRNO;
switch(error) {
case ENOENT:
case ESRCH:
status = ARES_EOF;
break;
default:
DEBUGF(fprintf(stderr, "fopen() failed with error: %d %s\n",
error, strerror(error)));
DEBUGF(fprintf(stderr, "Error opening file: %s\n", "/etc/host.conf"));
status = ARES_EFILE;
}
}
}
if ((status == ARES_EOF) && (!channel->lookups)) {
/* Tru64 uses /etc/svc.conf */
fp = fopen("/etc/svc.conf", "r");
if (fp) {
while ((status = ares__read_line(fp, &line, &linesize)) == ARES_SUCCESS)
{
if ((p = try_config(line, "hosts=")) && !channel->lookups)
status = config_lookup(channel, p, "bind", "local");
}
fclose(fp);
}
else {
error = ERRNO;
switch(error) {
case ENOENT:
case ESRCH:
status = ARES_EOF;
break;
default:
DEBUGF(fprintf(stderr, "fopen() failed with error: %d %s\n",
error, strerror(error)));
DEBUGF(fprintf(stderr, "Error opening file: %s\n", "/etc/svc.conf"));
status = ARES_EFILE;
}
}
}
if(line)
free(line);
}
#endif
/* Handle errors. */
if (status != ARES_EOF)
{
if (servers != NULL)
free(servers);
if (sortlist != NULL)
free(sortlist);
return status;
}
/* If we got any name server entries, fill them in. */
#ifdef WIN32
okay:
#endif
if (servers)
{
channel->servers = servers;
channel->nservers = nservers;
}
/* If we got any sortlist entries, fill them in. */
if (sortlist)
{
channel->sortlist = sortlist;
channel->nsort = nsort;
}
return ARES_SUCCESS;
}
static int init_by_defaults(ares_channel channel)
{
char hostname[MAXHOSTNAMELEN + 1];
if (channel->flags == -1)
channel->flags = 0;
if (channel->timeout == -1)
channel->timeout = DEFAULT_TIMEOUT;
if (channel->tries == -1)
channel->tries = DEFAULT_TRIES;
if (channel->ndots == -1)
channel->ndots = 1;
if (channel->udp_port == -1)
channel->udp_port = htons(NAMESERVER_PORT);
if (channel->tcp_port == -1)
channel->tcp_port = htons(NAMESERVER_PORT);
if (channel->nservers == -1)
{
/* If nobody specified servers, try a local named. */
channel->servers = malloc(sizeof(struct server_state));
if (!channel->servers)
return ARES_ENOMEM;
channel->servers[0].addr.s_addr = htonl(INADDR_LOOPBACK);
channel->nservers = 1;
}
if (channel->ndomains == -1)
{
/* Derive a default domain search list from the kernel hostname,
* or set it to empty if the hostname isn't helpful.
*/
if (gethostname(hostname, sizeof(hostname)) == -1
|| !strchr(hostname, '.'))
{
channel->ndomains = 0;
}
else
{
channel->domains = malloc(sizeof(char *));
if (!channel->domains)
return ARES_ENOMEM;
channel->ndomains = 0;
channel->domains[0] = strdup(strchr(hostname, '.') + 1);
if (!channel->domains[0])
return ARES_ENOMEM;
channel->ndomains = 1;
}
}
if (channel->nsort == -1)
{
channel->sortlist = NULL;
channel->nsort = 0;
}
if (!channel->lookups)
{
channel->lookups = strdup("fb");
if (!channel->lookups)
return ARES_ENOMEM;
}
return ARES_SUCCESS;
}
#ifndef WIN32
static int config_domain(ares_channel channel, char *str)
{
char *q;
/* Set a single search domain. */
q = str;
while (*q && !ISSPACE(*q))
q++;
*q = '\0';
return set_search(channel, str);
}
static int config_lookup(ares_channel channel, const char *str,
const char *bindch, const char *filech)
{
char lookups[3], *l;
const char *p;
/* Set the lookup order. Only the first letter of each work
* is relevant, and it has to be "b" for DNS or "f" for the
* host file. Ignore everything else.
*/
l = lookups;
p = str;
while (*p)
{
if ((*p == *bindch || *p == *filech) && l < lookups + 2) {
if (*p == *bindch) *l++ = 'b';
else *l++ = 'f';
}
while (*p && !ISSPACE(*p) && (*p != ','))
p++;
while (*p && (ISSPACE(*p) || (*p == ',')))
p++;
}
*l = '\0';
channel->lookups = strdup(lookups);
return (channel->lookups) ? ARES_SUCCESS : ARES_ENOMEM;
}
#endif
static int config_nameserver(struct server_state **servers, int *nservers,
char *str)
{
struct in_addr addr;
struct server_state *newserv;
/* On Windows, there may be more than one nameserver specified in the same
* registry key, so we parse it as a space or comma seperated list.
*/
#ifdef WIN32
char *p = str;
char *begin = str;
int more = 1;
while (more)
{
more = 0;
while (*p && !ISSPACE(*p) && *p != ',')
p++;
if (*p)
{
*p = '\0';
more = 1;
}
/* Skip multiple spaces or trailing spaces */
if (!*begin)
{
begin = ++p;
continue;
}
/* This is the part that actually sets the nameserver */
addr.s_addr = inet_addr(begin);
if (addr.s_addr == INADDR_NONE)
continue;
newserv = realloc(*servers, (*nservers + 1) * sizeof(struct server_state));
if (!newserv)
return ARES_ENOMEM;
newserv[*nservers].addr = addr;
*servers = newserv;
(*nservers)++;
if (!more)
break;
begin = ++p;
}
#else
/* Add a nameserver entry, if this is a valid address. */
addr.s_addr = inet_addr(str);
if (addr.s_addr == INADDR_NONE)
return ARES_SUCCESS;
newserv = realloc(*servers, (*nservers + 1) * sizeof(struct server_state));
if (!newserv)
return ARES_ENOMEM;
newserv[*nservers].addr = addr;
*servers = newserv;
(*nservers)++;
#endif
return ARES_SUCCESS;
}
#ifndef WIN32
static int config_sortlist(struct apattern **sortlist, int *nsort,
const char *str)
{
struct apattern pat;
const char *q;
/* Add sortlist entries. */
while (*str && *str != ';')
{
int bits;
char ipbuf[16], ipbufpfx[32];
/* Find just the IP */
q = str;
while (*q && *q != '/' && *q != ';' && !ISSPACE(*q))
q++;
memcpy(ipbuf, str, (int)(q-str));
ipbuf[(int)(q-str)] = '\0';
/* Find the prefix */
if (*q == '/')
{
const char *str2 = q+1;
while (*q && *q != ';' && !ISSPACE(*q))
q++;
memcpy(ipbufpfx, str, (int)(q-str));
ipbufpfx[(int)(q-str)] = '\0';
str = str2;
}
else
ipbufpfx[0] = '\0';
/* Lets see if it is CIDR */
/* First we'll try IPv6 */
if ((bits = ares_inet_net_pton(AF_INET6, ipbufpfx[0] ? ipbufpfx : ipbuf,
&pat.addr.addr6,
sizeof(pat.addr.addr6))) > 0)
{
pat.type = PATTERN_CIDR;
pat.mask.bits = (unsigned short)bits;
pat.family = AF_INET6;
if (!sortlist_alloc(sortlist, nsort, &pat))
return ARES_ENOMEM;
}
if (ipbufpfx[0] &&
(bits = ares_inet_net_pton(AF_INET, ipbufpfx, &pat.addr.addr4,
sizeof(pat.addr.addr4))) > 0)
{
pat.type = PATTERN_CIDR;
pat.mask.bits = (unsigned short)bits;
pat.family = AF_INET;
if (!sortlist_alloc(sortlist, nsort, &pat))
return ARES_ENOMEM;
}
/* See if it is just a regular IP */
else if (ip_addr(ipbuf, (int)(q-str), &pat.addr.addr4) == 0)
{
if (ipbufpfx[0])
{
memcpy(ipbuf, str, (int)(q-str));
ipbuf[(int)(q-str)] = '\0';
if (ip_addr(ipbuf, (int)(q - str), &pat.mask.addr.addr4) != 0)
natural_mask(&pat);
}
else
natural_mask(&pat);
pat.family = AF_INET;
pat.type = PATTERN_MASK;
if (!sortlist_alloc(sortlist, nsort, &pat))
return ARES_ENOMEM;
}
else
{
while (*q && *q != ';' && !ISSPACE(*q))
q++;
}
str = q;
while (ISSPACE(*str))
str++;
}
return ARES_SUCCESS;
}
#endif
static int set_search(ares_channel channel, const char *str)
{
int n;
const char *p, *q;
if(channel->ndomains != -1) {
/* if we already have some domains present, free them first */
for(n=0; n < channel->ndomains; n++)
free(channel->domains[n]);
free(channel->domains);
channel->domains = NULL;
channel->ndomains = -1;
}
/* Count the domains given. */
n = 0;
p = str;
while (*p)
{
while (*p && !ISSPACE(*p))
p++;
while (ISSPACE(*p))
p++;
n++;
}
if (!n)
{
channel->ndomains = 0;
return ARES_SUCCESS;
}
channel->domains = malloc(n * sizeof(char *));
if (!channel->domains)
return ARES_ENOMEM;
/* Now copy the domains. */
n = 0;
p = str;
while (*p)
{
channel->ndomains = n;
q = p;
while (*q && !ISSPACE(*q))
q++;
channel->domains[n] = malloc(q - p + 1);
if (!channel->domains[n])
return ARES_ENOMEM;
memcpy(channel->domains[n], p, q - p);
channel->domains[n][q - p] = 0;
p = q;
while (ISSPACE(*p))
p++;
n++;
}
channel->ndomains = n;
return ARES_SUCCESS;
}
static int set_options(ares_channel channel, const char *str)
{
const char *p, *q, *val;
p = str;
while (*p)
{
q = p;
while (*q && !ISSPACE(*q))
q++;
val = try_option(p, q, "ndots:");
if (val && channel->ndots == -1)
channel->ndots = atoi(val);
val = try_option(p, q, "retrans:");
if (val && channel->timeout == -1)
channel->timeout = atoi(val);
val = try_option(p, q, "retry:");
if (val && channel->tries == -1)
channel->tries = atoi(val);
p = q;
while (ISSPACE(*p))
p++;
}
return ARES_SUCCESS;
}
#ifndef WIN32
static char *try_config(char *s, const char *opt)
{
size_t len;
len = strlen(opt);
if (strncmp(s, opt, len) != 0 || !ISSPACE(s[len]))
return NULL;
s += len;
while (ISSPACE(*s))
s++;
return s;
}
#endif
static const char *try_option(const char *p, const char *q, const char *opt)
{
size_t len = strlen(opt);
return ((size_t)(q - p) > len && !strncmp(p, opt, len)) ? &p[len] : NULL;
}
#ifndef WIN32
static int sortlist_alloc(struct apattern **sortlist, int *nsort,
struct apattern *pat)
{
struct apattern *newsort;
newsort = realloc(*sortlist, (*nsort + 1) * sizeof(struct apattern));
if (!newsort)
return 0;
newsort[*nsort] = *pat;
*sortlist = newsort;
(*nsort)++;
return 1;
}
static int ip_addr(const char *ipbuf, int len, struct in_addr *addr)
{
/* Four octets and three periods yields at most 15 characters. */
if (len > 15)
return -1;
addr->s_addr = inet_addr(ipbuf);
if (addr->s_addr == INADDR_NONE && strcmp(ipbuf, "255.255.255.255") != 0)
return -1;
return 0;
}
static void natural_mask(struct apattern *pat)
{
struct in_addr addr;
/* Store a host-byte-order copy of pat in a struct in_addr. Icky,
* but portable.
*/
addr.s_addr = ntohl(pat->addr.addr4.s_addr);
/* This is out of date in the CIDR world, but some people might
* still rely on it.
*/
if (IN_CLASSA(addr.s_addr))
pat->mask.addr.addr4.s_addr = htonl(IN_CLASSA_NET);
else if (IN_CLASSB(addr.s_addr))
pat->mask.addr.addr4.s_addr = htonl(IN_CLASSB_NET);
else
pat->mask.addr.addr4.s_addr = htonl(IN_CLASSC_NET);
}
#endif
/* initialize an rc4 key. If possible a cryptographically secure random key
is generated using a suitable function (for example win32's RtlGenRandom as
described in
http://blogs.msdn.com/michael_howard/archive/2005/01/14/353379.aspx
otherwise the code defaults to cross-platform albeit less secure mechanism
using rand
*/
static void randomize_key(unsigned char* key,int key_data_len)
{
int randomized = 0;
int counter=0;
#ifdef WIN32
HMODULE lib=LoadLibrary("ADVAPI32.DLL");
if (lib) {
BOOLEAN (APIENTRY *pfn)(void*, ULONG) =
(BOOLEAN (APIENTRY *)(void*,ULONG))GetProcAddress(lib,"SystemFunction036");
if (pfn && pfn(key,key_data_len) )
randomized = 1;
FreeLibrary(lib);
}
#else /* !WIN32 */
#ifdef RANDOM_FILE
char buffer[256];
FILE *f = fopen(RANDOM_FILE, "rb");
if(f) {
size_t i;
size_t rc = fread(buffer, key_data_len, 1, f);
for(i=0; i<rc && counter < key_data_len; i++)
key[counter++]=buffer[i];
fclose(f);
}
#endif
#endif /* WIN32 */
if ( !randomized ) {
for (;counter<key_data_len;counter++)
key[counter]=rand() % 256;
}
}
static void init_id_key(rc4_key* key,int key_data_len)
{
unsigned char index1;
unsigned char index2;
unsigned char* state;
short counter;
unsigned char *key_data_ptr = 0;
key_data_ptr = calloc(1,key_data_len);
randomize_key(key->state,key_data_len);
state = &key->state[0];
for(counter = 0; counter < 256; counter++)
/* unnecessary AND but it keeps some compilers happier */
state[counter] = counter & 0xff;
key->x = 0;
key->y = 0;
index1 = 0;
index2 = 0;
for(counter = 0; counter < 256; counter++)
{
index2 = (key_data_ptr[index1] + state[counter] +
index2) % 256;
ARES_SWAP_BYTE(&state[counter], &state[index2]);
index1 = (index1 + 1) % key_data_len;
}
free(key_data_ptr);
}
short ares__generate_new_id(rc4_key* key)
{
short r=0;
ares__rc4(key, (unsigned char *)&r, sizeof(r));
return r;
}
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