src/src/structs.h

   1 /* $Cambridge: exim/src/src/structs.h,v 1.2 2004/12/16 15:11:47 tom Exp $ */
   2
   3 /*************************************************
   4 *     Exim - an Internet mail transport agent    *
   5 *************************************************/
   6
   7 /* Copyright (c) University of Cambridge 1995 - 2004 */
   8 /* See the file NOTICE for conditions of use and distribution. */
   9
  10
  11 /* Definitions of various structures. In addition, those that are visible for
  12 the compilation of local_scan() are defined in local_scan.h. These are
  13
  14   header_line
  15   optionlist
  16   recipient_item
  17
  18 For those declared here, we have to pre-declare some because of mutually
  19 recursive definitions in the auths, routers, and transports blocks. */
  20
  21 struct address_item;
  22 struct auth_info;
  23 struct driver_info;
  24 struct director_info;
  25 struct smtp_inblock;
  26 struct smtp_outblock;
  27 struct transport_info;
  28 struct router_info;
  29
  30 /* Structure for remembering macros for the configuration file */
  31
  32 typedef struct macro_item {
  33   struct  macro_item *next;
  34   BOOL    command_line;
  35   uschar *replacement;
  36   uschar  name[1];
  37 } macro_item;
  38
  39 /* Structure for bit tables for debugging and logging */
  40
  41 typedef struct bit_table {
  42   uschar *name;
  43   unsigned int bit;
  44 } bit_table;
  45
  46 /* Block for holding a uid and gid, possibly unset, and an initgroups flag. */
  47
  48 typedef struct ugid_block {
  49   uid_t   uid;
  50   gid_t   gid;
  51   BOOL    uid_set;
  52   BOOL    gid_set;
  53   BOOL    initgroups;
  54 } ugid_block;
  55
  56 /* Structure for holding information about a host for use mainly by routers,
  57 but also used when checking lists of hosts and when transporting. Looking up
  58 host addresses is done using this structure. */
  59
  60 typedef struct host_item {
  61   struct host_item *next;
  62   uschar *name;                   /* Host name */
  63   uschar *address;                /* IP address in text form */
  64   int     port;                   /* port value in host order (if SRV lookup) */
  65   int     mx;                     /* MX value if found via MX records */
  66   int     sort_key;               /* MX*1000 plus random "fraction" */
  67   int     status;                 /* Usable, unusable, or unknown */
  68   int     why;                    /* Why host is unusable */
  69   int     last_try;               /* Time of last try if known */
  70   BOOL    update_waiting;         /* Turned off if wait db not to be updated */
  71 } host_item;
  72
  73 /* Chain of rewrite rules, read from the rewrite config, or parsed from the
  74 rewrite_headers field of a transport. */
  75
  76 typedef struct rewrite_rule {
  77   struct rewrite_rule *next;
  78   int     flags;
  79   uschar *key;
  80   uschar *replacement;
  81 } rewrite_rule;
  82
  83 /* This structure is used to pass back configuration data from the smtp
  84 transport to the outside world. It is used during callback processing. If ever
  85 another remote transport were implemented, it could use the same structure. */
  86
  87 typedef struct transport_feedback {
  88   uschar *interface;
  89   uschar *port;
  90   uschar *protocol;
  91   uschar *hosts;
  92   BOOL   hosts_override;
  93   BOOL   hosts_randomize;
  94   BOOL   gethostbyname;
  95   BOOL   qualify_single;
  96   BOOL   search_parents;
  97 } transport_feedback;
  98
  99 /* Routers, transports, and authenticators have similar data blocks. Each
 100 driver that is compiled into the code is represented by a xxx_info block; the
 101 active drivers are represented by a chain of xxx_instance blocks. To make it
 102 possible to use the same code for reading the configuration files for all
 103 three, the layout of the start of the blocks is kept the same, and represented
 104 by the generic structures driver_info and driver_instance. */
 105
 106 typedef struct driver_instance {
 107   struct driver_instance *next;
 108   uschar *name;                   /* Instance name */
 109   struct driver_info *info;       /* Points to info for this driver */
 110   void   *options_block;          /* Pointer to private options */
 111   uschar *driver_name;            /* All start with this generic option */
 112 } driver_instance;
 113
 114 typedef struct driver_info {
 115   uschar *driver_name;            /* Name of driver */
 116   optionlist *options;            /* Table of private options names */
 117   int    *options_count;          /* -> Number of entries in table */
 118   void   *options_block;          /* Points to default private block */
 119   int     options_len;            /* Length of same in bytes */
 120   void  (*init)(                  /* Initialization entry point */
 121     struct driver_instance *);
 122 } driver_info;
 123
 124
 125 /* Structure for holding information about the configured transports. Some
 126 of the generally accessible options are set from the configuration file; others
 127 are set by transport initialization, since they can only be set for certain
 128 transports. They need to be generally accessible, however, as they are used by
 129 the main transport code. */
 130
 131 typedef struct transport_instance {
 132   struct transport_instance *next;
 133   uschar *name;                   /* Instance name */
 134   struct transport_info *info;    /* Info for this driver */
 135   void *options_block;            /* Pointer to private options */
 136   uschar *driver_name;            /* Must be first */
 137   int   (*setup)(                 /* Setup entry point */
 138     struct transport_instance *,
 139     struct address_item *,
 140     struct transport_feedback *,  /* For passing back config data */
 141     uschar **);                   /* For an error message */
 142                                   /**************************************/
 143   int     batch_max;              /* )                                  */
 144   uschar *batch_id;               /* )                                  */
 145   uschar *home_dir;               /* ) Used only for local transports   */
 146   uschar *current_dir;            /* )                                  */
 147                                   /**************************************/
 148   BOOL    multi_domain;           /* )                                  */
 149   BOOL    overrides_hosts;        /* ) Used only for remote transports  */
 150   int     max_addresses;          /* )                                  */
 151   int     connection_max_messages;/* )                                  */
 152                                   /**************************************/
 153   BOOL    deliver_as_creator;     /* Used only by pipe at present */
 154   BOOL    disable_logging;        /* For very weird requirements */
 155   BOOL    initgroups;             /* Initialize groups when setting uid */
 156   BOOL    uid_set;                /* uid is set */
 157   BOOL    gid_set;                /* gid is set */
 158   uid_t   uid;
 159   gid_t   gid;
 160   uschar *expand_uid;             /* Variable uid */
 161   uschar *expand_gid;             /* Variable gid */
 162   uschar *warn_message;           /* Used only by appendfile at present */
 163   uschar *shadow;                 /* Name of shadow transport */
 164   uschar *shadow_condition;       /* Condition for running it */
 165   uschar *filter_command;         /* For on-the-fly-filtering */
 166   uschar *add_headers;            /* Add these headers */
 167   uschar *remove_headers;         /* Remove these headers */
 168   uschar *return_path;            /* Overriding (rewriting) return path */
 169   uschar *debug_string;           /* Debugging output */
 170   uschar *message_size_limit;     /* Biggest message this transport handles */
 171   uschar *headers_rewrite;        /* Rules for rewriting headers */
 172   rewrite_rule *rewrite_rules;    /* Parsed rewriting rules */
 173   int     rewrite_existflags;     /* Bits showing which headers are rewritten */
 174   int     filter_timeout;         /* For transport filter timing */
 175   BOOL    body_only;              /* Deliver only the body */
 176   BOOL    delivery_date_add;      /* Add Delivery-Date header */
 177   BOOL    envelope_to_add;        /* Add Envelope-To header */
 178   BOOL    headers_only;           /* Deliver only the headers */
 179   BOOL    rcpt_include_affixes;   /* TRUE to retain affixes in RCPT commands */
 180   BOOL    return_path_add;        /* Add Return-Path header */
 181   BOOL    return_output;          /* TRUE if output should always be returned */
 182   BOOL    return_fail_output;     /* ditto, but only on failure */
 183   BOOL    log_output;             /* Similarly for logging */
 184   BOOL    log_fail_output;
 185   BOOL    log_defer_output;
 186   BOOL    retry_use_local_part;   /* Defaults true for local, false for remote */
 187 } transport_instance;
 188
 189
 190 /* Structure for holding information about a type of transport. The first six
 191 fields must match driver_info above. */
 192
 193 typedef struct transport_info {
 194   uschar *driver_name;            /* Driver name */
 195   optionlist *options;            /* Table of private options names */
 196   int    *options_count;          /* -> Number of entries in table */
 197   void   *options_block;          /* Points to default private block */
 198   int     options_len;            /* Length of same in bytes */
 199   void (*init)(                   /* Initialization function */
 200     struct transport_instance *);
 201 /****/
 202   BOOL (*code)(                   /* Main entry point */
 203     transport_instance *,
 204     struct address_item *);
 205   void (*tidyup)(                 /* Tidyup function */
 206     struct transport_instance *);
 207   void  (*closedown)(             /* For closing down a passed channel */
 208     struct transport_instance *);
 209   BOOL    local;                  /* TRUE for local transports */
 210 } transport_info;
 211
 212
 213
 214 /* Structure for holding information about the configured routers. */
 215
 216 typedef struct router_instance {
 217   struct router_instance *next;
 218   uschar *name;
 219   struct router_info *info;
 220   void   *options_block;          /* Pointer to private options */
 221   uschar *driver_name;            /* Must be first */
 222
 223   uschar *address_data;           /* Arbitrary data */
 224 #ifdef EXPERIMENTAL_BRIGHTMAIL
 225   uschar *bmi_rule;               /* Brightmail AntiSpam rule checking */
 226 #endif
 227   uschar *cannot_route_message;   /* Used when routing fails */
 228   uschar *condition;              /* General condition */
 229   uschar *current_directory;      /* For use during delivery */
 230   uschar *debug_string;           /* Debugging output */
 231   uschar *domains;                /* Specific domains */
 232   uschar *errors_to;              /* Errors address */
 233   uschar *expand_gid;             /* Expanded gid string */
 234   uschar *expand_uid;             /* Expanded uid string */
 235   uschar *expand_more;            /* Expanded more string */
 236   uschar *expand_unseen;          /* Expanded unseen string */
 237   uschar *extra_headers;          /* Additional headers */
 238   uschar *fallback_hosts;         /* For remote transports (text list) */
 239   uschar *home_directory;         /* For use during delivery */
 240   uschar *ignore_target_hosts;    /* Target hosts to ignore */
 241   uschar *local_parts;            /* Specific local parts */
 242   uschar *pass_router_name;       /* Router for passed address */
 243   uschar *prefix;                 /* Address prefix */
 244   uschar *redirect_router_name;   /* Router for generated address */
 245   uschar *remove_headers;         /* Removed headers */
 246   uschar *require_files;          /* File checks before router is run */
 247   uschar *router_home_directory;  /* For use while routing */
 248   uschar *self;                   /* Text option for handling self reference */
 249   uschar *senders;                /* Specific senders */
 250   uschar *suffix;                 /* Address suffix */
 251   uschar *translate_ip_address;   /* IP address translation fudgery */
 252   uschar *transport_name;         /* Transport name */
 253
 254   BOOL    address_test;           /* Use this router when testing addresses */
 255 #ifdef EXPERIMENTAL_BRIGHTMAIL
 256   BOOL    bmi_deliver_alternate;  /* TRUE => BMI said that message should be delivered to alternate location */
 257   BOOL    bmi_deliver_default;    /* TRUE => BMI said that message should be delivered to default location */
 258   BOOL    bmi_dont_deliver;       /* TRUE => BMI said that message should not be delivered at all */
 259 #endif
 260   BOOL    expn;                   /* Use this router when processing EXPN */
 261   BOOL    caseful_local_part;     /* TRUE => don't lowercase */
 262   BOOL    check_local_user;       /* TRUE => check local user */
 263   BOOL    disable_logging;        /* For very weird requirements */
 264   BOOL    fail_verify_recipient;  /* Fail verify if recipient match this router */
 265   BOOL    fail_verify_sender;     /* Fail verify if sender match this router */
 266   BOOL    gid_set;                /* Flag to indicate gid is set */
 267   BOOL    initgroups;             /* TRUE if initgroups is required */
 268   BOOL    log_as_local;           /* TRUE logs as a local delivery */
 269   BOOL    more;                   /* If FALSE, do no more if this one fails */
 270   BOOL    pass_on_timeout;        /* Treat timeout DEFERs as fails */
 271   BOOL    prefix_optional;        /* Just what it says */
 272   BOOL    repeat_use;             /* If FALSE, skip if ancestor used it */
 273   BOOL    retry_use_local_part;   /* Just what it says */
 274   BOOL    same_domain_copy_routing; /* TRUE => copy routing for same domain */
 275   BOOL    self_rewrite;           /* TRUE to rewrite headers if making local */
 276   BOOL    suffix_optional;        /* As it says */
 277   BOOL    verify_only;            /* Skip this router if not verifying */
 278   BOOL    verify_recipient;       /* Use this router when verifying a recipient*/
 279   BOOL    verify_sender;          /* Use this router when verifying a sender */
 280   BOOL    uid_set;                /* Flag to indicate uid is set */
 281   BOOL    unseen;                 /* If TRUE carry on, even after success */
 282
 283   int     self_code;              /* Encoded version of "self" */
 284   uid_t   uid;                    /* Fixed uid value */
 285   gid_t   gid;                    /* Fixed gid value */
 286
 287   host_item *fallback_hostlist;   /* For remote transport (block chain) */
 288   transport_instance *transport;  /* Transport block (when found) */
 289   struct router_instance *pass_router; /* Actual router for passed address */
 290   struct router_instance *redirect_router; /* Actual router for generated address */
 291 } router_instance;
 292
 293
 294 /* Structure for holding information about a type of router. The first six
 295 fields must match driver_info above. */
 296
 297 typedef struct router_info {
 298   uschar *driver_name;
 299   optionlist *options;            /* Table of private options names */
 300   int    *options_count;          /* -> Number of entries in table */
 301   void   *options_block;          /* Points to default private block */
 302   int     options_len;            /* Length of same in bytes */
 303   void (*init)(                   /* Initialization function */
 304     struct router_instance *);
 305 /****/
 306   int (*code)(                    /* Main entry point */
 307     router_instance *,
 308     struct address_item *,
 309     struct passwd *,
 310     BOOL,
 311     struct address_item **,
 312     struct address_item **,
 313     struct address_item **,
 314     struct address_item **);
 315   void (*tidyup)(                 /* Tidyup function */
 316     struct router_instance *);
 317   int     ri_flags;               /* Descriptive flags */
 318 } router_info;
 319
 320
 321 /* Structure for holding information about a lookup type. */
 322
 323 typedef struct lookup_info {
 324   uschar *name;                   /* e.g. "lsearch" */
 325   int type;                       /* query/singlekey/abs-file */
 326   void *(*open)(                  /* open function */
 327     uschar *,                     /* file name for those that have one */
 328     uschar **);                   /* for error message */
 329   BOOL (*check)(                  /* file checking function */
 330     void *,                       /* handle */
 331     uschar *,                     /* file name */
 332     int,                          /* modemask for file checking */
 333     uid_t *,                      /* owners for file checking */
 334     gid_t *,                      /* owngroups for file checking */
 335     uschar **);                   /* for error messages */
 336   int (*find)(                    /* find function */
 337     void *,                       /* handle */
 338     uschar *,                     /* file name or NULL */
 339     uschar *,                     /* key or query */
 340     int,                          /* length of key or query */
 341     uschar **,                    /* for returning answer */
 342     uschar **,                    /* for error message */
 343     BOOL *);                      /* to request cache cleanup */
 344   void (*close)(                  /* close function */
 345     void *);                      /* handle */
 346   void (*tidy)(void);             /* tidy function */
 347   uschar *(*quote)(               /* quoting function */
 348     uschar *,                     /* string to quote */
 349     uschar *);                    /* additional data from quote name */
 350 } lookup_info;
 351
 352
 353 /* Structure for holding information about the configured authentication
 354 mechanisms */
 355
 356 typedef struct auth_instance {
 357   struct auth_instance *next;
 358   uschar *name;                   /* Exim instance name */
 359   struct auth_info *info;         /* Pointer to driver info block */
 360   void   *options_block;          /* Pointer to private options */
 361   uschar *driver_name;            /* Must be first */
 362   uschar *advertise_condition;    /* Are we going to advertise this?*/
 363   uschar *public_name;            /* Advertised name */
 364   uschar *set_id;                 /* String to set as authenticated id */
 365   uschar *mail_auth_condition;    /* Condition for AUTH on MAIL command */
 366   uschar *server_debug_string;    /* Debugging output */
 367   BOOL    client;                 /* TRUE if client option(s) set */
 368   BOOL    server;                 /* TRUE if server options(s) set */
 369   BOOL    advertised;             /* Set TRUE when advertised */
 370 } auth_instance;
 371
 372
 373 /* Structure for holding information about an authentication mechanism. The
 374 first six fields must match driver_info above. */
 375
 376 typedef struct auth_info {
 377   uschar *driver_name;            /* e.g. "condition" */
 378   optionlist *options;            /* Table of private options names */
 379   int    *options_count;          /* -> Number of entries in table */
 380   void   *options_block;          /* Points to default private block */
 381   int     options_len;            /* Length of same in bytes */
 382   void (*init)(                   /* initialization function */
 383     struct auth_instance *);
 384 /****/
 385   int (*servercode)(              /* server function */
 386     auth_instance *,              /* the instance data */
 387     uschar *);                    /* rest of AUTH command */
 388   int (*clientcode)(              /* client function */
 389     struct auth_instance *,
 390     struct smtp_inblock *,        /* socket and input buffer */
 391     struct smtp_outblock *,       /* socket and output buffer */
 392     int,                          /* command timeout */
 393     uschar *,                     /* buffer for reading response */
 394     int);                         /* sizeof buffer */
 395 } auth_info;
 396
 397
 398 /* Structure for holding a single IP address and port; used for the chain of
 399 addresses and ports for the local host. Make the char string large enough to
 400 hold an IPv6 address. */
 401
 402 typedef struct ip_address_item {
 403   struct ip_address_item *next;
 404   int    port;
 405   BOOL   v6_include_v4;            /* Used in the daemon */
 406   uschar address[46];
 407 } ip_address_item;
 408
 409 /* Structure for chaining together arbitrary strings. */
 410
 411 typedef struct string_item {
 412   struct string_item *next;
 413   uschar *text;
 414 } string_item;
 415
 416 /* Information about a soft delivery failure, for use when calculating
 417 retry information. It's separate from the address block, because there
 418 can be a chain of them for SMTP deliveries where multiple IP addresses
 419 can be tried. */
 420
 421 typedef struct retry_item {
 422   struct retry_item *next;        /* for chaining */
 423   uschar *key;                    /* string identifying host/address/message */
 424   int     basic_errno;            /* error code for this destination */
 425   int     more_errno;             /* additional error information */
 426   uschar *message;                /* local error message */
 427   int     flags;                  /* see below */
 428 } retry_item;
 429
 430 /* Retry data flags */
 431
 432 #define rf_delete   0x0001        /* retry info is to be deleted */
 433 #define rf_host     0x0002        /* retry info is for a remote host */
 434 #define rf_message  0x0004        /* retry info is for a host+message */
 435
 436 /* Information about a constructed message that is to be sent using the
 437 autoreply transport. This is pointed to from the address block. */
 438
 439 typedef struct reply_item {
 440   uschar *from;                   /* ) */
 441   uschar *reply_to;               /* ) */
 442   uschar *to;                     /* ) */
 443   uschar *cc;                     /* ) specific header fields */
 444   uschar *bcc;                    /* ) */
 445   uschar *subject;                /* ) */
 446   uschar *headers;                /* misc other headers, concatenated */
 447   uschar *text;                   /* text string body */
 448   uschar *file;                   /* file body */
 449   BOOL    file_expand;            /* expand the body */
 450   int     expand_forbid;          /* expansion lockout flags */
 451   uschar *logfile;                /* file to keep a log in */
 452   uschar *oncelog;                /* file to keep records in for once only */
 453   time_t  once_repeat;            /* time to repeat "once only" */
 454   BOOL    return_message;         /* send back the original message */
 455 } reply_item;
 456
 457
 458 /* The address_item structure contains many fields which are used at various
 459 times while delivering a message. Some are used only for remote deliveries;
 460 some only for local. A particular set of fields is copied whenever a child
 461 address is created. For convenience, we keep those fields in a separate
 462 sub-structure so they can be copied in one go. This also means I won't forget
 463 to edit the various copying places when new to-be-copied fields are added. */
 464
 465 typedef struct address_item_propagated {
 466   uschar *address_data;           /* arbitrary data to keep with the address */
 467   uschar *domain_data;            /* from "domains" lookup */
 468   uschar *localpart_data;         /* from "local_parts" lookup */
 469   uschar *errors_address;         /* where to send errors (NULL => sender) */
 470   header_line *extra_headers;     /* additional headers */
 471   uschar *remove_headers;         /* list of those to remove */
 472 } address_item_propagated;
 473
 474 /* Bits for the flags field below */
 475
 476 #define af_allow_file          0x00000001 /* allow file in generated address */
 477 #define af_allow_pipe          0x00000002 /* allow pipe in generated address */
 478 #define af_allow_reply         0x00000004 /* allow autoreply in generated address */
 479 #define af_dr_retry_exists     0x00000008 /* router retry record exists */
 480 #define af_expand_pipe         0x00000010 /* expand pipe arguments */
 481 #define af_file                0x00000020 /* file delivery; always with pfr */
 482 #define af_gid_set             0x00000040 /* gid field is set */
 483 #define af_home_expanded       0x00000080 /* home_dir is already expanded */
 484 #define af_ignore_error        0x00000100 /* ignore delivery error */
 485 #define af_initgroups          0x00000200 /* use initgroups() for local transporting */
 486 #define af_local_host_removed  0x00000400 /* local host was backup */
 487 #define af_lt_retry_exists     0x00000800 /* local transport retry exists */
 488 #define af_pfr                 0x00001000 /* pipe or file or reply delivery */
 489 #define af_retry_skipped       0x00002000 /* true if retry caused some skipping */
 490 #define af_retry_timedout      0x00004000 /* true if retry timed out */
 491 #define af_uid_set             0x00008000 /* uid field is set */
 492 #define af_hide_child          0x00010000 /* hide child in bounce/defer msgs */
 493 #define af_sverify_told        0x00020000 /* sender verify failure notified */
 494 #define af_verify_pmfail       0x00040000 /* verify failure was postmaster callout */
 495 #define af_verify_nsfail       0x00080000 /* verify failure was null sender callout */
 496 #define af_homonym             0x00100000 /* an ancestor has same address */
 497 #define af_verify_routed       0x00200000 /* for cached sender verify: routed OK */
 498 #define af_verify_callout      0x00400000 /* for cached sender verify: callout was specified */
 499 #define af_include_affixes     0x00800000 /* delivered with affixes in RCPT */
 500 #define af_cert_verified       0x01000000 /* delivered with verified TLS cert */
 501
 502 /* These flags must be propagated when a child is created */
 503
 504 #define af_propagate           (af_ignore_error)
 505
 506 /* The main address structure. Note that fields that are to be copied to
 507 generated addresses should be put in the address_item_propagated structure (see
 508 above) rather than directly into the address_item structure. */
 509
 510 typedef struct address_item {
 511   struct address_item *next;      /* for chaining addresses */
 512   struct address_item *parent;    /* parent address */
 513   struct address_item *first;     /* points to first after group delivery */
 514   struct address_item *dupof;     /* points to address this is a duplicate of */
 515
 516   router_instance *start_router;  /* generated address starts here */
 517   router_instance *router;        /* the router that routed */
 518   transport_instance *transport;  /* the transport to use */
 519
 520   host_item *host_list;           /* host data for the transport */
 521   host_item *host_used;           /* host that took delivery or failed hard */
 522   host_item *fallback_hosts;      /* to try if delivery defers */
 523
 524   reply_item *reply;              /* data for autoreply */
 525   retry_item *retries;            /* chain of retry information */
 526
 527   uschar *address;                /* address being delivered or routed */
 528   uschar *unique;                 /* used for disambiguating */
 529   uschar *cc_local_part;          /* caseful local part */
 530   uschar *lc_local_part;          /* lowercased local part */
 531   uschar *local_part;             /* points to cc or lc version */
 532   uschar *prefix;                 /* stripped prefix of local part */
 533   uschar *suffix;                 /* stripped suffix of local part */
 534   uschar *domain;                 /* working domain (lower cased) */
 535
 536   uschar *address_retry_key;      /* retry key including full address */
 537   uschar *domain_retry_key;       /* retry key for domain only */
 538
 539   uschar *current_dir;            /* current directory for transporting */
 540   uschar *home_dir;               /* home directory for transporting */
 541   uschar *message;                /* error message */
 542   uschar *user_message;           /* error message that can be sent over SMTP
 543                                      or quoted in bounce message */
 544   uschar *onetime_parent;         /* saved original parent for onetime */
 545   uschar **pipe_expandn;          /* numeric expansions for pipe from filter */
 546   uschar *return_filename;        /* name of return file */
 547   uschar *self_hostname;          /* after self=pass */
 548   uschar *shadow_message;         /* info about shadow transporting */
 549
 550   #ifdef SUPPORT_TLS
 551   uschar *cipher;                 /* Cipher used for transport */
 552   uschar *peerdn;                 /* DN of server's certificate */
 553   #endif
 554
 555   uid_t   uid;                    /* uid for transporting */
 556   gid_t   gid;                    /* gid for transporting */
 557
 558   unsigned int flags;             /* a row of bits, defined above */
 559   unsigned int domain_cache[(MAX_NAMED_LIST * 2)/32];
 560   unsigned int localpart_cache[(MAX_NAMED_LIST * 2)/32];
 561   int     mode;                   /* mode for local transporting to a file */
 562   int     more_errno;             /* additional error information */
 563                                   /* (may need to hold a timestamp) */
 564
 565   short int basic_errno;          /* status after failure */
 566   short int child_count;          /* number of child addresses */
 567   short int return_file;          /* fileno of return data file */
 568   short int special_action;       /* ( used when when deferred or failed */
 569                                   /* (  also  */
 570                                   /* ( contains = or - when successful SMTP delivered */
 571                                   /* (  also  */
 572                                   /* ( contains verify rc in sender verify cache */
 573   short int transport_return;     /* result of delivery attempt */
 574   address_item_propagated p;      /* fields that are propagated to children */
 575 } address_item;
 576
 577 /* The table of header names consists of items of this type */
 578
 579 typedef struct {
 580   uschar *name;
 581   int     len;
 582   BOOL    allow_resent;
 583   int     htype;
 584 } header_name;
 585
 586 /* Chain of information about errors (e.g. bad addresses) */
 587
 588 typedef struct error_block {
 589   struct error_block *next;
 590   uschar *text1;
 591   uschar *text2;
 592 } error_block;
 593
 594 /* Chain of file names when processing the queue */
 595
 596 typedef struct queue_filename {
 597   struct queue_filename *next;
 598   uschar dir_uschar;
 599   uschar text[1];
 600 } queue_filename;
 601
 602 /* Chain of items of retry information, read from the retry config. */
 603
 604 typedef struct retry_rule {
 605   struct retry_rule *next;
 606   int    rule;
 607   int    timeout;
 608   int    p1;
 609   int    p2;
 610 } retry_rule;
 611
 612 typedef struct retry_config {
 613   struct retry_config *next;
 614   uschar *pattern;
 615   int     basic_errno;
 616   int     more_errno;
 617   uschar *senders;
 618   retry_rule *rules;
 619 } retry_config;
 620
 621 /* Structure for each node in a tree, of which there are various kinds */
 622
 623 typedef struct tree_node {
 624   struct tree_node *left;         /* pointer to left child */
 625   struct tree_node *right;        /* pointer to right child */
 626   union
 627     {
 628     void  *ptr;                   /* pointer to data */
 629     int val;                      /* or integer data */
 630     } data;
 631   uschar  balance;                /* balancing factor */
 632   uschar  name[1];                /* node name - variable length */
 633 } tree_node;
 634
 635 /* Structure for holding the handle and the cached last lookup for searches.
 636 This block is pointed to by the tree entry for the file. The file can get
 637 closed if too many are opened at once. There is a LRU chain for deciding which
 638 to close. */
 639
 640 typedef struct search_cache {
 641   void   *handle;                 /* lookup handle, or NULL if closed */
 642   int search_type;                /* search type */
 643   tree_node *up;                  /* LRU up pointer */
 644   tree_node *down;                /* LRU down pointer */
 645   tree_node *item_cache;          /* tree of cached results */
 646 } search_cache;
 647
 648 /* Structure for holding a partially decoded DNS record; the name has been
 649 uncompressed, but the data pointer is into the raw data. */
 650
 651 typedef struct {
 652   uschar  name[DNS_MAXNAME];      /* domain name */
 653   int     type;                   /* record type */
 654   int     size;                   /* size of data */
 655   uschar *data;                   /* pointer to data */
 656 } dns_record;
 657
 658 /* Structure for holding the result of a DNS query. */
 659
 660 typedef struct {
 661   int     answerlen;              /* length of the answer */
 662   uschar  answer[MAXPACKET];      /* the answer itself */
 663 } dns_answer;
 664
 665 /* Structure for holding the intermediate data while scanning a DNS answer
 666 block. */
 667
 668 typedef struct {
 669   int     rrcount;                /* count of RRs in the answer */
 670   uschar *aptr;                   /* pointer in the answer while scanning */
 671   dns_record srr;                 /* data from current record in scan */
 672 } dns_scan;
 673
 674 /* Structure for holding a chain of IP addresses that are extracted from
 675 an A, AAAA, or A6 record. For the first two, there is only ever one address,
 676 but the chaining feature of A6 allows for several addresses to be realized from
 677 a single initial A6 record. The structure defines the address field of length
 678 1. In use, a suitable sized block is obtained to hold the complete textual
 679 address. */
 680
 681 typedef struct dns_address {
 682   struct dns_address *next;
 683   uschar  address[1];
 684 } dns_address;
 685
 686 /* Structure used for holding intermediate data during MD5 computations. */
 687
 688 typedef struct md5 {
 689   unsigned int length;
 690   unsigned int abcd[4];
 691   }
 692 md5;
 693
 694 /* Structure used for holding intermediate data during SHA-1 computations. */
 695
 696 typedef struct sha1 {
 697   unsigned int H[5];
 698   unsigned int length;
 699   }
 700 sha1;
 701
 702 /* Structure used to hold incoming packets of SMTP responses for a specific
 703 socket. The packets which may contain multiple lines (and in some cases,
 704 multiple responses). */
 705
 706 typedef struct smtp_inblock {
 707   int     sock;                   /* the socket */
 708   int     buffersize;             /* the size of the buffer */
 709   uschar *ptr;                    /* current position in the buffer */
 710   uschar *ptrend;                 /* end of data in the buffer */
 711   uschar *buffer;                 /* the buffer itself */
 712 } smtp_inblock;
 713
 714 /* Structure used to hold buffered outgoing packets of SMTP commands for a
 715 specific socket. The packets which may contain multiple lines when pipelining
 716 is in use. */
 717
 718 typedef struct smtp_outblock {
 719   int     sock;                   /* the socket */
 720   int     cmd_count;              /* count of buffered commands */
 721   int     buffersize;             /* the size of the buffer */
 722   BOOL    authenticating;         /* TRUE when authenticating */
 723   uschar *ptr;                    /* current position in the buffer */
 724   uschar *buffer;                 /* the buffer itself */
 725 } smtp_outblock;
 726
 727 /* Structure to hold information about the source of redirection information */
 728
 729 typedef struct redirect_block {
 730   uschar *string;                 /* file name or string */
 731   uid_t  *owners;                 /* allowed file owners */
 732   gid_t  *owngroups;              /* allowed file groups */
 733   struct passwd *pw;              /* possible owner if not NULL */
 734   int     modemask;               /* forbidden bits */
 735   BOOL    isfile;                 /* TRUE if string is a file name */
 736   BOOL    check_owner;            /* TRUE, FALSE, or TRUE_UNSET */
 737   BOOL    check_group;            /* TRUE, FALSE, or TRUE_UNSET */
 738 } redirect_block;
 739
 740 /* Structure for passing arguments to check_host() */
 741
 742 typedef struct check_host_block {
 743   uschar *host_name;
 744   uschar *host_address;
 745   uschar *host_ipv4;
 746   BOOL   negative;
 747 } check_host_block;
 748
 749 /* Structure for remembering lookup data when caching the result of
 750 a lookup in a named list. */
 751
 752 typedef struct namedlist_cacheblock {
 753   struct namedlist_cacheblock *next;
 754   uschar *key;
 755   uschar *data;
 756 } namedlist_cacheblock;
 757
 758 /* Structure for holding data for an entry in a named list */
 759
 760 typedef struct namedlist_block {
 761   uschar *string;                    /* the list string */
 762   namedlist_cacheblock *cache_data;  /* cached domain_data or localpart_data */
 763   int number;                        /* the number of the list for caching */
 764 } namedlist_block;
 765
 766 /* Structures for Access Control Lists */
 767
 768 typedef struct acl_condition_block {
 769   struct acl_condition_block *next;
 770   uschar *arg;
 771   int type;
 772   union {
 773     BOOL negated;
 774     int varnumber;
 775   } u;
 776 } acl_condition_block;
 777
 778 typedef struct acl_block {
 779   struct acl_block *next;
 780   acl_condition_block *condition;
 781   int verb;
 782 } acl_block;
 783
 784 /* End of structs.h */