Expand PMF_FN_* macros.

[netbsd-mini2440.git] / external / ibm-public / postfix / dist / src / qmgr / qmgr.h

/*      $NetBSD$        */

/*++
/* NAME
/*      qmgr 3h
/* SUMMARY
/*      queue manager data structures
/* SYNOPSIS
/*      #include "qmgr.h"
/* DESCRIPTION
/* .nf

 /*
  * System library.
  */
#include <sys/time.h>
#include <time.h>

 /*
  * Utility library.
  */
#include <vstream.h>
#include <scan_dir.h>

 /*
  * Global library.
  */
#include <recipient_list.h>
#include <dsn.h>

 /*
  * The queue manager is built around lots of mutually-referring structures.
  * These typedefs save some typing.
  */
typedef struct QMGR_TRANSPORT QMGR_TRANSPORT;
typedef struct QMGR_QUEUE QMGR_QUEUE;
typedef struct QMGR_ENTRY QMGR_ENTRY;
typedef struct QMGR_MESSAGE QMGR_MESSAGE;
typedef struct QMGR_JOB QMGR_JOB;
typedef struct QMGR_PEER QMGR_PEER;
typedef struct QMGR_TRANSPORT_LIST QMGR_TRANSPORT_LIST;
typedef struct QMGR_QUEUE_LIST QMGR_QUEUE_LIST;
typedef struct QMGR_ENTRY_LIST QMGR_ENTRY_LIST;
typedef struct QMGR_JOB_LIST QMGR_JOB_LIST;
typedef struct QMGR_PEER_LIST QMGR_PEER_LIST;
typedef struct QMGR_SCAN QMGR_SCAN;
typedef struct QMGR_FEEDBACK QMGR_FEEDBACK;

 /*
  * Hairy macros to update doubly-linked lists.
  */
#define QMGR_LIST_ROTATE(head, object, peers) { \
    head.next->peers.prev = head.prev; \
    head.prev->peers.next = head.next; \
    head.next = object->peers.next; \
    head.next->peers.prev = 0; \
    head.prev = object; \
    object->peers.next = 0; \
}

#define QMGR_LIST_UNLINK(head, type, object, peers) { \
    type   _next = object->peers.next; \
    type   _prev = object->peers.prev; \
    if (_prev) _prev->peers.next = _next; \
        else head.next = _next; \
    if (_next) _next->peers.prev = _prev; \
        else head.prev = _prev; \
    object->peers.next = object->peers.prev = 0; \
}

#define QMGR_LIST_LINK(head, pred, object, succ, peers) { \
    object->peers.prev = pred; \
    object->peers.next = succ; \
    if (pred) pred->peers.next = object; \
    else head.next = object; \
    if (succ) succ->peers.prev = object; \
    else head.prev = object; \
}

#define QMGR_LIST_PREPEND(head, object, peers) { \
    object->peers.next = head.next; \
    object->peers.prev = 0; \
    if (head.next) { \
        head.next->peers.prev = object; \
    } else { \
        head.prev = object; \
    } \
    head.next = object; \
}

#define QMGR_LIST_APPEND(head, object, peers) { \
    object->peers.prev = head.prev; \
    object->peers.next = 0; \
    if (head.prev) { \
        head.prev->peers.next = object; \
    } else { \
        head.next = object; \
    } \
    head.prev = object; \
}

#define QMGR_LIST_INIT(head) { \
    head.prev = 0; \
    head.next = 0; \
}

 /*
  * Transports are looked up by name (when we have resolved a message), or
  * round-robin wise (when we want to distribute resources fairly).
  */
struct QMGR_TRANSPORT_LIST {
    QMGR_TRANSPORT *next;
    QMGR_TRANSPORT *prev;
};

extern struct HTABLE *qmgr_transport_byname;    /* transport by name */
extern QMGR_TRANSPORT_LIST qmgr_transport_list; /* transports, round robin */

 /*
  * Delivery agents provide feedback, as hints that Postfix should expend
  * more or fewer resources on a specific destination domain. The main.cf
  * file specifies how feedback affects delivery concurrency: add/subtract a
  * constant, a ratio of constants, or a constant divided by the delivery
  * concurrency; and it specifies how much feedback must accumulate between
  * concurrency updates.
  */
struct QMGR_FEEDBACK {
    int     hysteresis;                 /* to pass, need to be this tall */
    double  base;                       /* pre-computed from main.cf */
    int     index;                      /* none, window, sqrt(window) */
};

#define QMGR_FEEDBACK_IDX_NONE          0       /* no window dependence */
#define QMGR_FEEDBACK_IDX_WIN           1       /* 1/window dependence */
#if 0
#define QMGR_FEEDBACK_IDX_SQRT_WIN      2       /* 1/sqrt(window) dependence */
#endif

#ifdef QMGR_FEEDBACK_IDX_SQRT_WIN
#include <math.h>
#endif

extern void qmgr_feedback_init(QMGR_FEEDBACK *, const char *, const char *, const char *, const char *);

#ifndef QMGR_FEEDBACK_IDX_SQRT_WIN
#define QMGR_FEEDBACK_VAL(fb, win) \
    ((fb).index == QMGR_FEEDBACK_IDX_NONE ? (fb).base : (fb).base / (win))
#else
#define QMGR_FEEDBACK_VAL(fb, win) \
    ((fb).index == QMGR_FEEDBACK_IDX_NONE ? (fb).base : \
    (fb).index == QMGR_FEEDBACK_IDX_WIN ? (fb).base / (win) : \
    (fb).base / sqrt(win))
#endif

 /*
  * Each transport (local, smtp-out, bounce) can have one queue per next hop
  * name. Queues are looked up by next hop name (when we have resolved a
  * message destination), or round-robin wise (when we want to deliver
  * messages fairly).
  */
struct QMGR_QUEUE_LIST {
    QMGR_QUEUE *next;
    QMGR_QUEUE *prev;
};

struct QMGR_JOB_LIST {
    QMGR_JOB *next;
    QMGR_JOB *prev;
};

struct QMGR_TRANSPORT {
    int     flags;                      /* blocked, etc. */
    int     pending;                    /* incomplete DA connections */
    char   *name;                       /* transport name */
    int     dest_concurrency_limit;     /* concurrency per domain */
    int     init_dest_concurrency;      /* init. per-domain concurrency */
    int     recipient_limit;            /* recipients per transaction */
    int     rcpt_per_stack;             /* extra slots reserved for jobs put
                                         * on the job stack */
    int     rcpt_unused;                /* available in-core recipient slots */
    int     refill_limit;               /* recipient batch size for message
                                         * refill */
    int     refill_delay;               /* delay before message refill */
    int     slot_cost;                  /* cost of new preemption slot (# of
                                         * selected entries) */
    int     slot_loan;                  /* preemption boost offset and */
    int     slot_loan_factor;           /* factor, see qmgr_job_preempt() */
    int     min_slots;                  /* when preemption can take effect at
                                         * all */
    struct HTABLE *queue_byname;        /* queues indexed by domain */
    QMGR_QUEUE_LIST queue_list;         /* queues, round robin order */
    struct HTABLE *job_byname;          /* jobs indexed by queue id */
    QMGR_JOB_LIST job_list;             /* list of message jobs (1 per
                                         * message) ordered by scheduler */
    QMGR_JOB_LIST job_bytime;           /* jobs ordered by time since queued */
    QMGR_JOB *job_current;              /* keeps track of the current job */
    QMGR_JOB *job_next_unread;          /* next job with unread recipients */
    QMGR_JOB *candidate_cache;          /* cached result from
                                         * qmgr_job_candidate() */
    QMGR_JOB *candidate_cache_current;  /* current job tied to the candidate */
    time_t  candidate_cache_time;       /* when candidate_cache was last
                                         * updated */
    int     blocker_tag;                /* for marking blocker jobs */
    QMGR_TRANSPORT_LIST peers;          /* linkage */
    DSN    *dsn;                        /* why unavailable */
    QMGR_FEEDBACK pos_feedback;         /* positive feedback control */
    QMGR_FEEDBACK neg_feedback;         /* negative feedback control */
    int     fail_cohort_limit;          /* flow shutdown control */
    int     rate_delay;                 /* suspend per delivery */
};

#define QMGR_TRANSPORT_STAT_DEAD        (1<<1)

typedef void (*QMGR_TRANSPORT_ALLOC_NOTIFY) (QMGR_TRANSPORT *, VSTREAM *);
extern QMGR_TRANSPORT *qmgr_transport_select(void);
extern void qmgr_transport_alloc(QMGR_TRANSPORT *, QMGR_TRANSPORT_ALLOC_NOTIFY);
extern void qmgr_transport_throttle(QMGR_TRANSPORT *, DSN *);
extern void qmgr_transport_unthrottle(QMGR_TRANSPORT *);
extern QMGR_TRANSPORT *qmgr_transport_create(const char *);
extern QMGR_TRANSPORT *qmgr_transport_find(const char *);

#define QMGR_TRANSPORT_THROTTLED(t)     ((t)->flags & QMGR_TRANSPORT_STAT_DEAD)

 /*
  * Each next hop (e.g., a domain name) has its own queue of pending message
  * transactions. The "todo" queue contains messages that are to be delivered
  * to this next hop. When a message is elected for transmission, it is moved
  * from the "todo" queue to the "busy" queue. Messages are taken from the
  * "todo" queue in round-robin order.
  */
struct QMGR_ENTRY_LIST {
    QMGR_ENTRY *next;
    QMGR_ENTRY *prev;
};

struct QMGR_QUEUE {
    int     dflags;                     /* delivery request options */
    time_t  last_done;                  /* last delivery completion */
    char   *name;                       /* domain name or address */
    char   *nexthop;                    /* domain name */
    int     todo_refcount;              /* queue entries (todo list) */
    int     busy_refcount;              /* queue entries (busy list) */
    int     window;                     /* slow open algorithm */
    double  success;                    /* accumulated positive feedback */
    double  failure;                    /* accumulated negative feedback */
    double  fail_cohorts;               /* pseudo-cohort failure count */
    QMGR_TRANSPORT *transport;          /* transport linkage */
    QMGR_ENTRY_LIST todo;               /* todo queue entries */
    QMGR_ENTRY_LIST busy;               /* messages on the wire */
    QMGR_QUEUE_LIST peers;              /* neighbor queues */
    DSN    *dsn;                        /* why unavailable */
    time_t  clog_time_to_warn;          /* time of last warning */
    int     blocker_tag;                /* tagged if blocks job list */
};

#define QMGR_QUEUE_TODO 1               /* waiting for service */
#define QMGR_QUEUE_BUSY 2               /* recipients on the wire */

extern int qmgr_queue_count;

extern QMGR_QUEUE *qmgr_queue_create(QMGR_TRANSPORT *, const char *, const char *);
extern void qmgr_queue_done(QMGR_QUEUE *);
extern void qmgr_queue_throttle(QMGR_QUEUE *, DSN *);
extern void qmgr_queue_unthrottle(QMGR_QUEUE *);
extern QMGR_QUEUE *qmgr_queue_find(QMGR_TRANSPORT *, const char *);
extern void qmgr_queue_suspend(QMGR_QUEUE *, int);

 /*
  * Exclusive queue states. Originally there were only two: "throttled" and
  * "not throttled". It was natural to encode these in the queue window size.
  * After 10 years it's not practical to rip out all the working code and
  * change representations, so we just clean up the names a little.
  * 
  * Note: only the "ready" state can reach every state (including itself);
  * non-ready states can reach only the "ready" state. Other transitions are
  * forbidden, because they would result in dangling event handlers.
  */
#define QMGR_QUEUE_STAT_THROTTLED       0       /* back-off timer */
#define QMGR_QUEUE_STAT_SUSPENDED       -1      /* voluntary delay timer */
#define QMGR_QUEUE_STAT_SAVED           -2      /* delayed cleanup timer */
#define QMGR_QUEUE_STAT_BAD             -3      /* can't happen */

#define QMGR_QUEUE_READY(q)     ((q)->window > 0)
#define QMGR_QUEUE_THROTTLED(q) ((q)->window == QMGR_QUEUE_STAT_THROTTLED)
#define QMGR_QUEUE_SUSPENDED(q) ((q)->window == QMGR_QUEUE_STAT_SUSPENDED)
#define QMGR_QUEUE_SAVED(q)     ((q)->window == QMGR_QUEUE_STAT_SAVED)
#define QMGR_QUEUE_BAD(q)       ((q)->window <= QMGR_QUEUE_STAT_BAD)

#define QMGR_QUEUE_STATUS(q) ( \
            QMGR_QUEUE_READY(q) ? "ready" : \
            QMGR_QUEUE_THROTTLED(q) ? "throttled" : \
            QMGR_QUEUE_SUSPENDED(q) ? "suspended" : \
            QMGR_QUEUE_SAVED(q) ? "saved" : \
            "invalid queue status" \
        )

 /*
  * Structure of one next-hop queue entry. In order to save some copying
  * effort we allow multiple recipients per transaction.
  */
struct QMGR_ENTRY {
    VSTREAM *stream;                    /* delivery process */
    QMGR_MESSAGE *message;              /* message info */
    RECIPIENT_LIST rcpt_list;           /* as many as it takes */
    QMGR_QUEUE *queue;                  /* parent linkage */
    QMGR_PEER *peer;                    /* parent linkage */
    QMGR_ENTRY_LIST queue_peers;        /* per queue neighbor entries */
    QMGR_ENTRY_LIST peer_peers;         /* per peer neighbor entries */
};

extern QMGR_ENTRY *qmgr_entry_select(QMGR_PEER *);
extern void qmgr_entry_unselect(QMGR_ENTRY *);
extern void qmgr_entry_move_todo(QMGR_QUEUE *, QMGR_ENTRY *);
extern void qmgr_entry_done(QMGR_ENTRY *, int);
extern QMGR_ENTRY *qmgr_entry_create(QMGR_PEER *, QMGR_MESSAGE *);

 /*
  * All common in-core information about a message is kept here. When all
  * recipients have been tried the message file is linked to the "deferred"
  * queue (some hosts not reachable), to the "bounce" queue (some recipients
  * were rejected), and is then removed from the "active" queue.
  */
struct QMGR_MESSAGE {
    int     flags;                      /* delivery problems */
    int     qflags;                     /* queuing flags */
    int     tflags;                     /* tracing flags */
    long    tflags_offset;              /* offset for killing */
    int     rflags;                     /* queue file read flags */
    VSTREAM *fp;                        /* open queue file or null */
    int     refcount;                   /* queue entries */
    int     single_rcpt;                /* send one rcpt at a time */
    struct timeval arrival_time;        /* start of receive transaction */
    time_t  create_time;                /* queue file create time */
    struct timeval active_time;         /* time of entry into active queue */
    time_t  queued_time;                /* sanitized time when moved to the
                                         * active queue */
    time_t  refill_time;                /* sanitized time of last message
                                         * refill */
    long    warn_offset;                /* warning bounce flag offset */
    time_t  warn_time;                  /* time next warning to be sent */
    long    data_offset;                /* data seek offset */
    char   *queue_name;                 /* queue name */
    char   *queue_id;                   /* queue file */
    char   *encoding;                   /* content encoding */
    char   *sender;                     /* complete address */
    char   *dsn_envid;                  /* DSN envelope ID */
    int     dsn_ret;                    /* DSN headers/full */
    char   *verp_delims;                /* VERP delimiters */
    char   *filter_xport;               /* filtering transport */
    char   *inspect_xport;              /* inspecting transport */
    char   *redirect_addr;              /* info@spammer.tld */
    long    data_size;                  /* data segment size */
    long    cont_length;                /* message content length */
    long    rcpt_offset;                /* more recipients here */
    char   *client_name;                /* client hostname */
    char   *client_addr;                /* client address */
    char   *client_port;                /* client port */
    char   *client_proto;               /* client protocol */
    char   *client_helo;                /* helo parameter */
    char   *sasl_method;                /* SASL method */
    char   *sasl_username;              /* SASL user name */
    char   *sasl_sender;                /* SASL sender */
    char   *rewrite_context;            /* address qualification */
    RECIPIENT_LIST rcpt_list;           /* complete addresses */
    int     rcpt_count;                 /* used recipient slots */
    int     rcpt_limit;                 /* maximum read in-core */
    int     rcpt_unread;                /* # of recipients left in queue file */
    QMGR_JOB_LIST job_list;             /* jobs delivering this message (1
                                         * per transport) */
};

 /*
  * Flags 0-15 are reserved for qmgr_user.h.
  */
#define QMGR_READ_FLAG_SEEN_ALL_NON_RCPT        (1<<16)

#define QMGR_MESSAGE_LOCKED     ((QMGR_MESSAGE *) 1)

extern int qmgr_message_count;
extern int qmgr_recipient_count;

extern void qmgr_message_free(QMGR_MESSAGE *);
extern void qmgr_message_update_warn(QMGR_MESSAGE *);
extern void qmgr_message_kill_record(QMGR_MESSAGE *, long);
extern QMGR_MESSAGE *qmgr_message_alloc(const char *, const char *, int, mode_t);
extern QMGR_MESSAGE *qmgr_message_realloc(QMGR_MESSAGE *);

#define QMGR_MSG_STATS(stats, message) \
    MSG_STATS_INIT2(stats, \
                    incoming_arrival, message->arrival_time, \
                    active_arrival, message->active_time)

 /*
  * Sometimes it's required to access the transport queues and entries on per
  * message basis. That's what the QMGR_JOB structure is for - it groups all
  * per message information within each transport using a list of QMGR_PEER
  * structures. These structures in turn correspond with per message
  * QMGR_QUEUE structure and list all per message QMGR_ENTRY structures.
  */
struct QMGR_PEER_LIST {
    QMGR_PEER *next;
    QMGR_PEER *prev;
};

struct QMGR_JOB {
    QMGR_MESSAGE *message;              /* message delivered by this job */
    QMGR_TRANSPORT *transport;          /* transport this job belongs to */
    QMGR_JOB_LIST message_peers;        /* per message neighbor linkage */
    QMGR_JOB_LIST transport_peers;      /* per transport neighbor linkage */
    QMGR_JOB_LIST time_peers;           /* by time neighbor linkage */
    QMGR_JOB *stack_parent;             /* stack parent */
    QMGR_JOB_LIST stack_children;       /* all stack children */
    QMGR_JOB_LIST stack_siblings;       /* stack children linkage */
    int     stack_level;                /* job stack nesting level (-1 means
                                         * it's not on the lists at all) */
    int     blocker_tag;                /* tagged if blocks the job list */
    struct HTABLE *peer_byname;         /* message job peers, indexed by
                                         * domain */
    QMGR_PEER_LIST peer_list;           /* list of message job peers */
    int     slots_used;                 /* slots used during preemption */
    int     slots_available;            /* slots available for preemption (in
                                         * multiples of slot_cost) */
    int     selected_entries;           /* # of entries selected for delivery
                                         * so far */
    int     read_entries;               /* # of entries read in-core so far */
    int     rcpt_count;                 /* used recipient slots */
    int     rcpt_limit;                 /* available recipient slots */
};

struct QMGR_PEER {
    QMGR_JOB *job;                      /* job handling this peer */
    QMGR_QUEUE *queue;                  /* queue corresponding with this peer */
    int     refcount;                   /* peer entries */
    QMGR_ENTRY_LIST entry_list;         /* todo message entries queued for
                                         * this peer */
    QMGR_PEER_LIST peers;               /* neighbor linkage */
};

extern QMGR_ENTRY *qmgr_job_entry_select(QMGR_TRANSPORT *);
extern QMGR_PEER *qmgr_peer_select(QMGR_JOB *);
extern void qmgr_job_blocker_update(QMGR_QUEUE *);

extern QMGR_JOB *qmgr_job_obtain(QMGR_MESSAGE *, QMGR_TRANSPORT *);
extern void qmgr_job_free(QMGR_JOB *);
extern void qmgr_job_move_limits(QMGR_JOB *);

extern QMGR_PEER *qmgr_peer_create(QMGR_JOB *, QMGR_QUEUE *);
extern QMGR_PEER *qmgr_peer_find(QMGR_JOB *, QMGR_QUEUE *);
extern QMGR_PEER *qmgr_peer_obtain(QMGR_JOB *, QMGR_QUEUE *);
extern void qmgr_peer_free(QMGR_PEER *);

 /*
  * qmgr_defer.c
  */
extern void qmgr_defer_transport(QMGR_TRANSPORT *, DSN *);
extern void qmgr_defer_todo(QMGR_QUEUE *, DSN *);
extern void qmgr_defer_recipient(QMGR_MESSAGE *, RECIPIENT *, DSN *);

 /*
  * qmgr_bounce.c
  */
extern void qmgr_bounce_recipient(QMGR_MESSAGE *, RECIPIENT *, DSN *);

 /*
  * qmgr_deliver.c
  */
extern int qmgr_deliver_concurrency;
extern void qmgr_deliver(QMGR_TRANSPORT *, VSTREAM *);

 /*
  * qmgr_active.c
  */
extern int qmgr_active_feed(QMGR_SCAN *, const char *);
extern void qmgr_active_drain(void);
extern void qmgr_active_done(QMGR_MESSAGE *);

 /*
  * qmgr_move.c
  */
extern void qmgr_move(const char *, const char *, time_t);

 /*
  * qmgr_enable.c
  */
extern void qmgr_enable_all(void);
extern void qmgr_enable_transport(QMGR_TRANSPORT *);
extern void qmgr_enable_queue(QMGR_QUEUE *);

 /*
  * Queue scan context.
  */
struct QMGR_SCAN {
    char   *queue;                      /* queue name */
    int     flags;                      /* private, this run */
    int     nflags;                     /* private, next run */
    struct SCAN_DIR *handle;            /* scan */
};

 /*
  * Flags that control queue scans or destination selection. These are
  * similar to the QMGR_REQ_XXX request codes.
  */
#define QMGR_SCAN_START (1<<0)          /* start now/restart when done */
#define QMGR_SCAN_ALL   (1<<1)          /* all queue file time stamps */
#define QMGR_FLUSH_ONCE (1<<2)          /* unthrottle once */
#define QMGR_FLUSH_DFXP (1<<3)          /* override defer_transports */
#define QMGR_FLUSH_EACH (1<<4)          /* unthrottle per message */

 /*
  * qmgr_scan.c
  */
extern QMGR_SCAN *qmgr_scan_create(const char *);
extern void qmgr_scan_request(QMGR_SCAN *, int);
extern char *qmgr_scan_next(QMGR_SCAN *);

 /*
  * qmgr_error.c
  */
extern QMGR_TRANSPORT *qmgr_error_transport(const char *);
extern QMGR_QUEUE *qmgr_error_queue(const char *, DSN *);
extern char *qmgr_error_nexthop(DSN *);

/* LICENSE
/* .ad
/* .fi
/*      The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/*      Wietse Venema
/*      IBM T.J. Watson Research
/*      P.O. Box 704
/*      Yorktown Heights, NY 10598, USA
/*
/*      Preemptive scheduler enhancements:
/*      Patrik Rak
/*      Modra 6
/*      155 00, Prague, Czech Republic
/*--*/