cleanup_map1n.c

[詳解]

/*++
/* NAME
/*  cleanup_map1n 3
/* SUMMARY
/*  one-to-many address mapping
/* SYNOPSIS
/*  #include <cleanup.h>
/*
/*  ARGV    *cleanup_map1n_internal(state, addr, maps, propagate)
/*  CLEANUP_STATE *state;
/*  const char *addr;
/*  MAPS    *maps;
/*  int propagate;
/* DESCRIPTION
/*  This module implements one-to-many table mapping via table lookup.
/*  Table lookups are done with quoted (externalized) address forms.
/*  The process is recursive. The recursion terminates when the
/*  left-hand side appears in its own expansion.
/*
/*  cleanup_map1n_internal() is the interface for addresses in
/*  internal (unquoted) form.
/* DIAGNOSTICS
/*  When the maximal expansion or recursion limit is reached,
/*  the alias is not expanded and the CLEANUP_STAT_DEFER error
/*  is raised with reason "4.6.0 Alias expansion error".
/*
/*  When table lookup fails, the alias is not expanded and the
/*  CLEANUP_STAT_WRITE error is raised with reason "4.6.0 Alias
/*  expansion error".
/* SEE ALSO
/*  mail_addr_map(3) address mappings
/*  mail_addr_find(3) address lookups
/* 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
/*
/*  Wietse Venema
/*  Google, Inc.
/*  111 8th Avenue
/*  New York, NY 10011, USA
/*--*/

/* System library. */

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

/* Utility library. */

#include <mymalloc.h>
#include <msg.h>
#include <argv.h>
#include <vstring.h>
#include <dict.h>
#include <stringops.h>

/* Global library. */

#include <mail_params.h>
#include <mail_addr_map.h>
#include <cleanup_user.h>
#include <quote_822_local.h>
#include <been_here.h>

/* Application-specific. */

#include "cleanup.h"

/* cleanup_map1n_internal - one-to-many table lookups */

ARGV   *cleanup_map1n_internal(CLEANUP_STATE *state, const char *addr,
                           MAPS *maps, int propagate)
{
    ARGV   *argv;
    ARGV   *lookup;
    int     count;
    int     i;
    int     arg;
    BH_TABLE *been_here;
    char   *saved_lhs;

    /*
     * Initialize.
     */
    argv = argv_alloc(1);
    argv_add(argv, addr, ARGV_END);
    argv_terminate(argv);
    been_here = been_here_init(0, BH_FLAG_FOLD);

    /*
     * Rewrite the address vector in place. With each map lookup result,
     * split it into separate addresses, then rewrite and flatten each
     * address, and repeat the process. Beware: argv is being changed, so we
     * must index the array explicitly, instead of running along it with a
     * pointer.
     */
#define UPDATE(ptr,new) do { \
    if (ptr) myfree(ptr); ptr = mystrdup(new); \
    } while (0)
#define STR vstring_str
#define RETURN(x) do { \
    been_here_free(been_here); return (x); \
    } while (0)
#define UNEXPAND(argv, addr) do { \
    argv_truncate((argv), 0); argv_add((argv), (addr), (char *) 0); \
    } while (0)

    for (arg = 0; arg < argv->argc; arg++) {
    if (argv->argc > var_virt_expan_limit) {
        msg_warn("%s: unreasonable %s map expansion size for %s -- "
             "message not accepted, try again later",
             state->queue_id, maps->title, addr);
        state->errs |= CLEANUP_STAT_DEFER;
        UPDATE(state->reason, "4.6.0 Alias expansion error");
        UNEXPAND(argv, addr);
        RETURN(argv);
    }
    for (count = 0; /* void */ ; count++) {

        /*
         * Don't expand an address that already expanded into itself.
         */
        if (been_here_check_fixed(been_here, argv->argv[arg]) != 0)
        break;
        if (count >= var_virt_recur_limit) {
        msg_warn("%s: unreasonable %s map nesting for %s -- "
             "message not accepted, try again later",
             state->queue_id, maps->title, addr);
        state->errs |= CLEANUP_STAT_DEFER;
        UPDATE(state->reason, "4.6.0 Alias expansion error");
        UNEXPAND(argv, addr);
        RETURN(argv);
        }
        if ((lookup = mail_addr_map_internal(maps, argv->argv[arg],
                         propagate)) != 0) {
        saved_lhs = mystrdup(argv->argv[arg]);
        for (i = 0; i < lookup->argc; i++) {
            if (strlen(lookup->argv[i]) > var_virt_addrlen_limit) {
            msg_warn("%s: unreasonable %s result %.300s... -- "
                 "message not accepted, try again later",
                 state->queue_id, maps->title, lookup->argv[i]);
            state->errs |= CLEANUP_STAT_DEFER;
            UPDATE(state->reason, "4.6.0 Alias expansion error");
            UNEXPAND(argv, addr);
            RETURN(argv);
            }
            if (i == 0) {
            UPDATE(argv->argv[arg], lookup->argv[i]);
            } else {
            argv_add(argv, lookup->argv[i], ARGV_END);
            argv_terminate(argv);
            }

            /*
             * Allow an address to expand into itself once.
             */
            if (strcasecmp_utf8(saved_lhs, lookup->argv[i]) == 0)
            been_here_fixed(been_here, saved_lhs);
        }
        myfree(saved_lhs);
        argv_free(lookup);
        } else if (maps->error != 0) {
        msg_warn("%s: %s map lookup problem for %s -- "
             "message not accepted, try again later",
             state->queue_id, maps->title, addr);
        state->errs |= CLEANUP_STAT_WRITE;
        UPDATE(state->reason, "4.6.0 Alias expansion error");
        UNEXPAND(argv, addr);
        RETURN(argv);
        } else {
        break;
        }
    }
    }
    RETURN(argv);
}