1#ifndef __ARES_PRIVATE_H
2#define __ARES_PRIVATE_H
3
4
5/* Copyright 1998 by the Massachusetts Institute of Technology.
6 * Copyright (C) 2004-2010 by Daniel Stenberg
7 *
8 * Permission to use, copy, modify, and distribute this
9 * software and its documentation for any purpose and without
10 * fee is hereby granted, provided that the above copyright
11 * notice appear in all copies and that both that copyright
12 * notice and this permission notice appear in supporting
13 * documentation, and that the name of M.I.T. not be used in
14 * advertising or publicity pertaining to distribution of the
15 * software without specific, written prior permission.
16 * M.I.T. makes no representations about the suitability of
17 * this software for any purpose.  It is provided "as is"
18 * without express or implied warranty.
19 */
20
21/*
22 * Define WIN32 when build target is Win32 API
23 */
24
25#if (defined(_WIN32) || defined(__WIN32__)) && !defined(WIN32)
26#define WIN32
27#endif
28
29#include <stdio.h>
30#include <sys/types.h>
31
32#ifdef HAVE_NETINET_IN_H
33#include <netinet/in.h>
34#endif
35
36#ifdef WATT32
37#include <tcp.h>
38#include <sys/ioctl.h>
39#define writev(s,v,c)     writev_s(s,v,c)
40#define HAVE_WRITEV 1
41#endif
42
43#ifdef NETWARE
44#include <time.h>
45#endif
46
47#define DEFAULT_TIMEOUT         5000 /* milliseconds */
48#define DEFAULT_TRIES           4
49#ifndef INADDR_NONE
50#define INADDR_NONE 0xffffffff
51#endif
52
53#if defined(WIN32) && !defined(WATT32)
54
55#define WIN_NS_9X      "System\\CurrentControlSet\\Services\\VxD\\MSTCP"
56#define WIN_NS_NT_KEY  "System\\CurrentControlSet\\Services\\Tcpip\\Parameters"
57#define NAMESERVER     "NameServer"
58#define DHCPNAMESERVER "DhcpNameServer"
59#define DATABASEPATH   "DatabasePath"
60#define WIN_PATH_HOSTS  "\\hosts"
61
62#elif defined(WATT32)
63
64#define PATH_RESOLV_CONF "/dev/ENV/etc/resolv.conf"
65
66#elif defined(NETWARE)
67
68#define PATH_RESOLV_CONF "sys:/etc/resolv.cfg"
69#define PATH_HOSTS              "sys:/etc/hosts"
70
71#elif defined(__riscos__)
72
73#define PATH_HOSTS             "InetDBase:Hosts"
74
75#else
76
77#define PATH_RESOLV_CONF        "/etc/resolv.conf"
78#ifdef ETC_INET
79#define PATH_HOSTS              "/etc/inet/hosts"
80#else
81#define PATH_HOSTS              "/etc/hosts"
82#endif
83
84#endif
85
86#define ARES_ID_KEY_LEN 31
87
88#include "ares_ipv6.h"
89#include "ares_llist.h"
90
91#ifndef HAVE_GETENV
92#  include "ares_getenv.h"
93#  define getenv(ptr) ares_getenv(ptr)
94#endif
95
96#ifndef HAVE_STRDUP
97#  include "ares_strdup.h"
98#  define strdup(ptr) ares_strdup(ptr)
99#endif
100
101#ifndef HAVE_STRCASECMP
102#  include "ares_strcasecmp.h"
103#  define strcasecmp(p1,p2) ares_strcasecmp(p1,p2)
104#endif
105
106#ifndef HAVE_STRNCASECMP
107#  include "ares_strcasecmp.h"
108#  define strncasecmp(p1,p2,n) ares_strncasecmp(p1,p2,n)
109#endif
110
111#ifndef HAVE_WRITEV
112#  include "ares_writev.h"
113#  define writev(s,ptr,cnt) ares_writev(s,ptr,cnt)
114#endif
115
116struct ares_addr {
117  int family;
118  union {
119    struct in_addr       addr4;
120    struct ares_in6_addr addr6;
121  } addr;
122};
123#define addrV4 addr.addr4
124#define addrV6 addr.addr6
125
126struct query;
127
128struct send_request {
129  /* Remaining data to send */
130  const unsigned char *data;
131  size_t len;
132
133  /* The query for which we're sending this data */
134  struct query* owner_query;
135  /* The buffer we're using, if we have our own copy of the packet */
136  unsigned char *data_storage;
137
138  /* Next request in queue */
139  struct send_request *next;
140};
141
142struct server_state {
143  struct ares_addr addr;
144  ares_socket_t udp_socket;
145  ares_socket_t tcp_socket;
146
147  /* Mini-buffer for reading the length word */
148  unsigned char tcp_lenbuf[2];
149  int tcp_lenbuf_pos;
150  int tcp_length;
151
152  /* Buffer for reading actual TCP data */
153  unsigned char *tcp_buffer;
154  int tcp_buffer_pos;
155
156  /* TCP output queue */
157  struct send_request *qhead;
158  struct send_request *qtail;
159
160  /* Which incarnation of this connection is this? We don't want to
161   * retransmit requests into the very same socket, but if the server
162   * closes on us and we re-open the connection, then we do want to
163   * re-send. */
164  int tcp_connection_generation;
165
166  /* Circular, doubly-linked list of outstanding queries to this server */
167  struct list_node queries_to_server;
168
169  /* Link back to owning channel */
170  ares_channel channel;
171
172  /* Is this server broken? We mark connections as broken when a
173   * request that is queued for sending times out.
174   */
175  int is_broken;
176};
177
178/* State to represent a DNS query */
179struct query {
180  /* Query ID from qbuf, for faster lookup, and current timeout */
181  unsigned short qid;
182  struct timeval timeout;
183
184  /*
185   * Links for the doubly-linked lists in which we insert a query.
186   * These circular, doubly-linked lists that are hash-bucketed based
187   * the attributes we care about, help making most important
188   * operations O(1).
189   */
190  struct list_node queries_by_qid;    /* hopefully in same cache line as qid */
191  struct list_node queries_by_timeout;
192  struct list_node queries_to_server;
193  struct list_node all_queries;
194
195  /* Query buf with length at beginning, for TCP transmission */
196  unsigned char *tcpbuf;
197  int tcplen;
198
199  /* Arguments passed to ares_send() (qbuf points into tcpbuf) */
200  const unsigned char *qbuf;
201  int qlen;
202  ares_callback callback;
203  void *arg;
204
205  /* Query status */
206  int try_count; /* Number of times we tried this query already. */
207  int server; /* Server this query has last been sent to. */
208  struct query_server_info *server_info;   /* per-server state */
209  int using_tcp;
210  int error_status;
211  int timeouts; /* number of timeouts we saw for this request */
212};
213
214/* Per-server state for a query */
215struct query_server_info {
216  int skip_server;  /* should we skip server, due to errors, etc? */
217  int tcp_connection_generation;  /* into which TCP connection did we send? */
218};
219
220/* An IP address pattern; matches an IP address X if X & mask == addr */
221#define PATTERN_MASK 0x1
222#define PATTERN_CIDR 0x2
223
224struct apattern {
225  union
226  {
227    struct in_addr       addr4;
228    struct ares_in6_addr addr6;
229  } addr;
230  union
231  {
232    struct in_addr       addr4;
233    struct ares_in6_addr addr6;
234    unsigned short       bits;
235  } mask;
236  int family;
237  unsigned short type;
238};
239
240typedef struct rc4_key
241{
242  unsigned char state[256];
243  unsigned char x;
244  unsigned char y;
245} rc4_key;
246
247struct ares_channeldata {
248  /* Configuration data */
249  int flags;
250  int timeout; /* in milliseconds */
251  int tries;
252  int ndots;
253  int rotate; /* if true, all servers specified are used */
254  int udp_port;
255  int tcp_port;
256  int socket_send_buffer_size;
257  int socket_receive_buffer_size;
258  char **domains;
259  int ndomains;
260  struct apattern *sortlist;
261  int nsort;
262  char *lookups;
263
264  /* For binding to local devices and/or IP addresses.  Leave
265   * them null/zero for no binding.
266   */
267  char local_dev_name[32];
268  unsigned int local_ip4;
269  unsigned char local_ip6[16];
270
271  int optmask; /* the option bitfield passed in at init time */
272
273  /* Server addresses and communications state */
274  struct server_state *servers;
275  int nservers;
276
277  /* ID to use for next query */
278  unsigned short next_id;
279  /* key to use when generating new ids */
280  rc4_key id_key;
281
282  /* Generation number to use for the next TCP socket open/close */
283  int tcp_connection_generation;
284
285  /* The time at which we last called process_timeouts(). Uses integer seconds
286     just to draw the line somewhere. */
287  time_t last_timeout_processed;
288
289  /* Last server we sent a query to. */
290  int last_server;
291
292  /* Circular, doubly-linked list of queries, bucketed various ways.... */
293  /* All active queries in a single list: */
294  struct list_node all_queries;
295  /* Queries bucketed by qid, for quickly dispatching DNS responses: */
296#define ARES_QID_TABLE_SIZE 2048
297  struct list_node queries_by_qid[ARES_QID_TABLE_SIZE];
298  /* Queries bucketed by timeout, for quickly handling timeouts: */
299#define ARES_TIMEOUT_TABLE_SIZE 1024
300  struct list_node queries_by_timeout[ARES_TIMEOUT_TABLE_SIZE];
301
302  ares_sock_state_cb sock_state_cb;
303  void *sock_state_cb_data;
304
305  ares_sock_create_callback sock_create_cb;
306  void *sock_create_cb_data;
307};
308
309/* return true if now is exactly check time or later */
310int ares__timedout(struct timeval *now,
311                   struct timeval *check);
312/* add the specific number of milliseconds to the time in the first argument */
313int ares__timeadd(struct timeval *now,
314                  int millisecs);
315/* return time offset between now and (future) check, in milliseconds */
316long ares__timeoffset(struct timeval *now,
317                      struct timeval *check);
318/* returns ARES_SUCCESS if library has been initialized */
319int ares_library_initialized(void);
320void ares__rc4(rc4_key* key,unsigned char *buffer_ptr, int buffer_len);
321void ares__send_query(ares_channel channel, struct query *query,
322                      struct timeval *now);
323void ares__close_sockets(ares_channel channel, struct server_state *server);
324int ares__get_hostent(FILE *fp, int family, struct hostent **host);
325int ares__read_line(FILE *fp, char **buf, size_t *bufsize);
326void ares__free_query(struct query *query);
327unsigned short ares__generate_new_id(rc4_key* key);
328struct timeval ares__tvnow(void);
329int ares__expand_name_for_response(const unsigned char *encoded,
330                                   const unsigned char *abuf, int alen,
331                                   char **s, long *enclen);
332void ares__init_servers_state(ares_channel channel);
333void ares__destroy_servers_state(ares_channel channel);
334#if 0 /* Not used */
335long ares__tvdiff(struct timeval t1, struct timeval t2);
336#endif
337
338#define ARES_SWAP_BYTE(a,b) \
339  { unsigned char swapByte = *(a);  *(a) = *(b);  *(b) = swapByte; }
340
341#define SOCK_STATE_CALLBACK(c, s, r, w)                                 \
342  do {                                                                  \
343    if ((c)->sock_state_cb)                                             \
344      (c)->sock_state_cb((c)->sock_state_cb_data, (s), (r), (w));       \
345  } while (0)
346
347#ifdef CURLDEBUG
348/* This is low-level hard-hacking memory leak tracking and similar. Using the
349   libcurl lowlevel code from within library is ugly and only works when
350   c-ares is built and linked with a similarly curldebug-enabled libcurl,
351   but we do this anyway for convenience. */
352#include "../lib/memdebug.h"
353#endif
354
355#endif /* __ARES_PRIVATE_H */
356