master_conf.c

[詳解]

/*++
/* NAME
/*  master_conf 3
/* SUMMARY
/*  Postfix master - master.cf file processing
/* SYNOPSIS
/*  #include "master.h"
/*
/*  void    master_config(serv)
/*  MASTER_SERV *serv;
/*
/*  void    master_refresh(serv)
/*  MASTER_SERV *serv;
/* DESCRIPTION
/*  Use master_config() to read the master.cf configuration file
/*  during program initialization.
/*
/*  Use master_refresh() to re-read the master.cf configuration file
/*  when the process is already running.
/* DIAGNOSTICS
/* BUGS
/* SEE ALSO
/*  master_ent(3), configuration file programmatic interface.
/* 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
/*--*/

/* System libraries. */

#include <sys_defs.h>
#include <unistd.h>
#include <string.h>

/* Utility library. */

#include <msg.h>
#include <argv.h>

/* Application-specific. */

#include "master.h"

/* master_refresh - re-read configuration table */

void    master_refresh(void)
{
    MASTER_SERV *serv;
    MASTER_SERV **servp;

    /*
     * Mark all existing services.
     */
    for (serv = master_head; serv != 0; serv = serv->next)
    serv->flags |= MASTER_FLAG_MARK;

    /*
     * Read the master.cf configuration file. The master_conf() routine
     * unmarks services upon update. New services are born with the mark bit
     * off. After this, anything with the mark bit on should be removed.
     */
    master_config();

    /*
     * Delete all services that are still marked - they disappeared from the
     * configuration file and are therefore no longer needed.
     */
    for (servp = &master_head; (serv = *servp) != 0; /* void */ ) {
    if ((serv->flags & MASTER_FLAG_MARK) != 0) {
        *servp = serv->next;
        master_stop_service(serv);
        free_master_ent(serv);
    } else {
        servp = &serv->next;
    }
    }
}

/* master_config - read config file */

void    master_config(void)
{
    MASTER_SERV *entry;
    MASTER_SERV *serv;

#define STR_DIFF    strcmp
#define STR_SAME    !strcmp
#define SWAP(type,a,b)  { type temp = a; a = b; b = temp; }

    /*
     * A service is identified by its endpoint name AND by its transport
     * type, not just by its name alone. The name is unique within its
     * transport type. XXX Service privacy is encoded in the service name.
     */
    set_master_ent();
    while ((entry = get_master_ent()) != 0) {
    if (msg_verbose)
        print_master_ent(entry);
    for (serv = master_head; serv != 0; serv = serv->next)
        if (STR_SAME(serv->name, entry->name) && serv->type == entry->type)
        break;

    /*
     * Add a new service entry. We do not really care in what order the
     * service entries are kept in memory.
     */
    if (serv == 0) {
        entry->next = master_head;
        master_head = entry;
        master_start_service(entry);
    }

    /*
     * Update an existing service entry. Make the current generation of
     * child processes commit suicide whenever it is convenient. The next
     * generation of child processes will run with the new configuration
     * settings.
     */
    else {
        serv->flags &= ~MASTER_FLAG_MARK;
        if (entry->flags & MASTER_FLAG_CONDWAKE)
        serv->flags |= MASTER_FLAG_CONDWAKE;
        else
        serv->flags &= ~MASTER_FLAG_CONDWAKE;
        serv->wakeup_time = entry->wakeup_time;
        serv->max_proc = entry->max_proc;
        serv->throttle_delay = entry->throttle_delay;
        SWAP(char *, serv->ext_name, entry->ext_name);
        SWAP(char *, serv->path, entry->path);
        SWAP(ARGV *, serv->args, entry->args);
        SWAP(char *, serv->stress_param_val, entry->stress_param_val);
        master_restart_service(serv, DO_CONF_RELOAD);
        free_master_ent(entry);
    }
    }
    end_master_ent();
}