ceph/src/c-ares/ares_private.h

   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 #ifdef HAVE_NETINET_IN_H
  30 #include <netinet/in.h>
  31 #endif
  32
  33 #ifdef WATT32
  34 #include <tcp.h>
  35 #include <sys/ioctl.h>
  36 #define writev(s,v,c)     writev_s(s,v,c)
  37 #define HAVE_WRITEV 1
  38 #endif
  39
  40 #define DEFAULT_TIMEOUT         5000 /* milliseconds */
  41 #define DEFAULT_TRIES           4
  42 #ifndef INADDR_NONE
  43 #define INADDR_NONE 0xffffffff
  44 #endif
  45
  46 #ifdef CARES_EXPOSE_STATICS
  47 /* Make some internal functions visible for testing */
  48 #define STATIC_TESTABLE
  49 #else
  50 #define STATIC_TESTABLE static
  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 #include "ares_strdup.h"
  97
  98 #ifndef HAVE_STRCASECMP
  99 #  include "ares_strcasecmp.h"
 100 #  define strcasecmp(p1,p2) ares_strcasecmp(p1,p2)
 101 #endif
 102
 103 #ifndef HAVE_STRNCASECMP
 104 #  include "ares_strcasecmp.h"
 105 #  define strncasecmp(p1,p2,n) ares_strncasecmp(p1,p2,n)
 106 #endif
 107
 108 #ifndef HAVE_WRITEV
 109 #  include "ares_writev.h"
 110 #  define writev(s,ptr,cnt) ares_writev(s,ptr,cnt)
 111 #endif
 112
 113 /********* EDNS defines section ******/
 114 #define EDNSPACKETSZ   1280  /* Reasonable UDP payload size, as suggested
 115                                 in RFC2671 */
 116 #define MAXENDSSZ      4096  /* Maximum (local) limit for edns packet size */
 117 #define EDNSFIXEDSZ    11    /* Size of EDNS header */
 118 /********* EDNS defines section ******/
 119
 120 struct ares_addr {
 121   int family;
 122   union {
 123     struct in_addr       addr4;
 124     struct ares_in6_addr addr6;
 125   } addr;
 126   int udp_port;  /* stored in network order */
 127   int tcp_port;  /* stored in network order */
 128 };
 129 #define addrV4 addr.addr4
 130 #define addrV6 addr.addr6
 131
 132 struct query;
 133
 134 struct send_request {
 135   /* Remaining data to send */
 136   const unsigned char *data;
 137   size_t len;
 138
 139   /* The query for which we're sending this data */
 140   struct query* owner_query;
 141   /* The buffer we're using, if we have our own copy of the packet */
 142   unsigned char *data_storage;
 143
 144   /* Next request in queue */
 145   struct send_request *next;
 146 };
 147
 148 struct server_state {
 149   struct ares_addr addr;
 150   ares_socket_t udp_socket;
 151   ares_socket_t tcp_socket;
 152
 153   /* Mini-buffer for reading the length word */
 154   unsigned char tcp_lenbuf[2];
 155   int tcp_lenbuf_pos;
 156   int tcp_length;
 157
 158   /* Buffer for reading actual TCP data */
 159   unsigned char *tcp_buffer;
 160   int tcp_buffer_pos;
 161
 162   /* TCP output queue */
 163   struct send_request *qhead;
 164   struct send_request *qtail;
 165
 166   /* Which incarnation of this connection is this? We don't want to
 167    * retransmit requests into the very same socket, but if the server
 168    * closes on us and we re-open the connection, then we do want to
 169    * re-send. */
 170   int tcp_connection_generation;
 171
 172   /* Circular, doubly-linked list of outstanding queries to this server */
 173   struct list_node queries_to_server;
 174
 175   /* Link back to owning channel */
 176   ares_channel channel;
 177
 178   /* Is this server broken? We mark connections as broken when a
 179    * request that is queued for sending times out.
 180    */
 181   int is_broken;
 182 };
 183
 184 /* State to represent a DNS query */
 185 struct query {
 186   /* Query ID from qbuf, for faster lookup, and current timeout */
 187   unsigned short qid;
 188   struct timeval timeout;
 189
 190   /*
 191    * Links for the doubly-linked lists in which we insert a query.
 192    * These circular, doubly-linked lists that are hash-bucketed based
 193    * the attributes we care about, help making most important
 194    * operations O(1).
 195    */
 196   struct list_node queries_by_qid;    /* hopefully in same cache line as qid */
 197   struct list_node queries_by_timeout;
 198   struct list_node queries_to_server;
 199   struct list_node all_queries;
 200
 201   /* Query buf with length at beginning, for TCP transmission */
 202   unsigned char *tcpbuf;
 203   int tcplen;
 204
 205   /* Arguments passed to ares_send() (qbuf points into tcpbuf) */
 206   const unsigned char *qbuf;
 207   int qlen;
 208   ares_callback callback;
 209   void *arg;
 210
 211   /* Query status */
 212   int try_count; /* Number of times we tried this query already. */
 213   int server; /* Server this query has last been sent to. */
 214   struct query_server_info *server_info;   /* per-server state */
 215   int using_tcp;
 216   int error_status;
 217   int timeouts; /* number of timeouts we saw for this request */
 218 };
 219
 220 /* Per-server state for a query */
 221 struct query_server_info {
 222   int skip_server;  /* should we skip server, due to errors, etc? */
 223   int tcp_connection_generation;  /* into which TCP connection did we send? */
 224 };
 225
 226 /* An IP address pattern; matches an IP address X if X & mask == addr */
 227 #define PATTERN_MASK 0x1
 228 #define PATTERN_CIDR 0x2
 229
 230 struct apattern {
 231   union
 232   {
 233     struct in_addr       addr4;
 234     struct ares_in6_addr addr6;
 235   } addr;
 236   union
 237   {
 238     struct in_addr       addr4;
 239     struct ares_in6_addr addr6;
 240     unsigned short       bits;
 241   } mask;
 242   int family;
 243   unsigned short type;
 244 };
 245
 246 typedef struct rc4_key
 247 {
 248   unsigned char state[256];
 249   unsigned char x;
 250   unsigned char y;
 251 } rc4_key;
 252
 253 struct ares_channeldata {
 254   /* Configuration data */
 255   int flags;
 256   int timeout; /* in milliseconds */
 257   int tries;
 258   int ndots;
 259   int rotate; /* if true, all servers specified are used */
 260   int udp_port; /* stored in network order */
 261   int tcp_port; /* stored in network order */
 262   int socket_send_buffer_size;
 263   int socket_receive_buffer_size;
 264   char **domains;
 265   int ndomains;
 266   struct apattern *sortlist;
 267   int nsort;
 268   char *lookups;
 269   int ednspsz;
 270
 271   /* For binding to local devices and/or IP addresses.  Leave
 272    * them null/zero for no binding.
 273    */
 274   char local_dev_name[32];
 275   unsigned int local_ip4;
 276   unsigned char local_ip6[16];
 277
 278   int optmask; /* the option bitfield passed in at init time */
 279
 280   /* Server addresses and communications state */
 281   struct server_state *servers;
 282   int nservers;
 283
 284   /* ID to use for next query */
 285   unsigned short next_id;
 286   /* key to use when generating new ids */
 287   rc4_key id_key;
 288
 289   /* Generation number to use for the next TCP socket open/close */
 290   int tcp_connection_generation;
 291
 292   /* The time at which we last called process_timeouts(). Uses integer seconds
 293      just to draw the line somewhere. */
 294   time_t last_timeout_processed;
 295
 296   /* Last server we sent a query to. */
 297   int last_server;
 298
 299   /* Circular, doubly-linked list of queries, bucketed various ways.... */
 300   /* All active queries in a single list: */
 301   struct list_node all_queries;
 302   /* Queries bucketed by qid, for quickly dispatching DNS responses: */
 303 #define ARES_QID_TABLE_SIZE 2048
 304   struct list_node queries_by_qid[ARES_QID_TABLE_SIZE];
 305   /* Queries bucketed by timeout, for quickly handling timeouts: */
 306 #define ARES_TIMEOUT_TABLE_SIZE 1024
 307   struct list_node queries_by_timeout[ARES_TIMEOUT_TABLE_SIZE];
 308
 309   ares_sock_state_cb sock_state_cb;
 310   void *sock_state_cb_data;
 311
 312   ares_sock_create_callback sock_create_cb;
 313   void *sock_create_cb_data;
 314
 315   ares_sock_config_callback sock_config_cb;
 316   void *sock_config_cb_data;
 317
 318   const struct ares_socket_functions * sock_funcs;
 319   void *sock_func_cb_data;
 320 };
 321
 322 /* Memory management functions */
 323 extern void *(*ares_malloc)(size_t size);
 324 extern void *(*ares_realloc)(void *ptr, size_t size);
 325 extern void (*ares_free)(void *ptr);
 326
 327 /* return true if now is exactly check time or later */
 328 int ares__timedout(struct timeval *now,
 329                    struct timeval *check);
 330
 331 void ares__send_query(ares_channel channel, struct query *query,
 332                       struct timeval *now);
 333 void ares__close_sockets(ares_channel channel, struct server_state *server);
 334 int ares__get_hostent(FILE *fp, int family, struct hostent **host);
 335 int ares__read_line(FILE *fp, char **buf, size_t *bufsize);
 336 void ares__free_query(struct query *query);
 337 unsigned short ares__generate_new_id(rc4_key* key);
 338 struct timeval ares__tvnow(void);
 339 int ares__expand_name_for_response(const unsigned char *encoded,
 340                                    const unsigned char *abuf, int alen,
 341                                    char **s, long *enclen);
 342 void ares__init_servers_state(ares_channel channel);
 343 void ares__destroy_servers_state(ares_channel channel);
 344 #if 0 /* Not used */
 345 long ares__tvdiff(struct timeval t1, struct timeval t2);
 346 #endif
 347
 348 void ares__socket_close(ares_channel, ares_socket_t);
 349
 350 #define ARES_SWAP_BYTE(a,b) \
 351   { unsigned char swapByte = *(a);  *(a) = *(b);  *(b) = swapByte; }
 352
 353 #define SOCK_STATE_CALLBACK(c, s, r, w)                                 \
 354   do {                                                                  \
 355     if ((c)->sock_state_cb)                                             \
 356       (c)->sock_state_cb((c)->sock_state_cb_data, (s), (r), (w));       \
 357   } WHILE_FALSE
 358
 359 #ifdef CURLDEBUG
 360 /* This is low-level hard-hacking memory leak tracking and similar. Using the
 361    libcurl lowlevel code from within library is ugly and only works when
 362    c-ares is built and linked with a similarly curldebug-enabled libcurl,
 363    but we do this anyway for convenience. */
 364 #define HEADER_CURL_SETUP_ONCE_H
 365 #include "../lib/memdebug.h"
 366 #endif
 367
 368 #endif /* __ARES_PRIVATE_H */