dsn.c

[詳解]

/*++
/* NAME
/*  dsn
/* SUMMARY
/*  RFC-compliant delivery status information
/* SYNOPSIS
/*  #include <dsn.h>
/*
/*  typedef struct {
/* .in +4
/*      const char *status; /* RFC 3463 status */
/*      const char *action; /* null or RFC 3464 action */
/*      const char *reason; /* human-readable text */
/*      const char *dtype;  /* null or diagnostic type */
/*      const char *dtext;  /* null or diagnostic code */
/*      const char *mtype;  /* null or MTA type */
/*      const char *mname;  /* null or remote MTA */
/* .in -4
/*  } DSN;
/*
/*  DSN *dsn_create(status, action, reason, dtype, dtext, mtype, mname)
/*  const char *status;
/*  const char *action;
/*  const char *reason;
/*  const char *dtype;
/*  const char *dtext;
/*  const char *mtype;
/*  const char *mname;
/*
/*  DSN *DSN_COPY(dsn)
/*  DSN *dsn;
/*
/*  void    dsn_free(dsn)
/*  DSN *dsn;
/*
/*  DSN *DSN_ASSIGN(dsn, status, action, reason, dtype, dtext,
/*                      mtype, mname)
/*  DSN *dsn;
/*  const char *status;
/*  const char *action;
/*  const char *reason;
/*  const char *dtype;
/*  const char *dtext;
/*  const char *mtype;
/*  const char *mname;
/*
/*  DSN *DSN_SIMPLE(dsn, status, action, reason)
/*  DSN *dsn;
/*  const char *status;
/*  const char *action;
/*  const char *reason;
/* DESCRIPTION
/*  This module maintains delivery error information. For a
/*  description of structure field members see "Arguments"
/*  below.  Function-like names spelled in upper case are macros.
/*  These may evaluate some arguments more than once.
/*
/*  dsn_create() creates a DSN structure and copies its arguments.
/*  The DSN structure should be destroyed with dsn_free().
/*
/*  DSN_COPY() creates a deep copy of its argument.
/*
/*  dsn_free() destroys a DSN structure and makes its storage
/*  available for reuse.
/*
/*  DSN_ASSIGN() updates a DSN structure and DOES NOT copy
/*  arguments or free memory.  The result DSN structure must
/*  NOT be passed to dsn_free(). DSN_ASSIGN() is typically used
/*  for stack-based short-lived storage.
/*
/*  DSN_SIMPLE() takes the minimally required subset of all the
/*  attributes and sets the rest to empty strings.
/*  This is a wrapper around the DSN_ASSIGN() macro.
/*
/*  Arguments:
/* .IP reason
/*  Human-readable text, used for logging purposes, and for
/*  updating the message-specific \fBbounce\fR or \fIdefer\fR
/*  logfile.
/* .IP status
/*  Enhanced status code as specified in RFC 3463.
/* .IP action
/*  DSN_NO_ACTION, empty string, or action as defined in RFC 3464.
/*  If no action is specified, a default action is chosen.
/* .IP dtype
/*  DSN_NO_DTYPE, empty string, or diagnostic code type as
/*  specified in RFC 3464.
/* .IP dtext
/*  DSN_NO_DTEXT, empty string, or diagnostic code as specified
/*  in RFC 3464.
/* .IP mtype
/*  DSN_NO_MTYPE, empty string, DSN_MTYPE_DNS or DSN_MTYPE_UNIX.
/* .IP mname
/*  DSN_NO_MNAME, empty string, or remote MTA as specified in
/*  RFC 3464.
/* DIAGNOSTICS
/*  Panic: null or empty status or reason.
/*  Fatal: out of memory.
/* 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 library. */

#include <sys_defs.h>

/* Utility library. */

#include <msg.h>
#include <mymalloc.h>

/* Global library. */

#include <dsn.h>

/* dsn_create - create DSN structure */

DSN    *dsn_create(const char *status, const char *action, const char *reason,
                   const char *dtype, const char *dtext,
                   const char *mtype, const char *mname)
{
    const char *myname = "dsn_create";
    DSN    *dsn;

    dsn = (DSN *) mymalloc(sizeof(*dsn));

    /*
     * Status and reason must not be empty. Other members may be empty
     * strings.
     * 
     * Early implementations represented unavailable information with null
     * pointers. This resulted in code that was difficult to maintain. We now
     * use empty strings instead. For safety sake we keep the null pointer
     * test for input, but we always convert to empty string on output.
     */
#define NULL_OR_EMPTY(s) ((s) == 0 || *(s) == 0)

    if (NULL_OR_EMPTY(status))
    msg_panic("%s: null dsn status", myname);
    else
    dsn->status = mystrdup(status);

    if (NULL_OR_EMPTY(action))
    dsn->action = mystrdup("");
    else
    dsn->action = mystrdup(action);

    if (NULL_OR_EMPTY(reason))
    msg_panic("%s: null dsn reason", myname);
    else
    dsn->reason = mystrdup(reason);

    if (NULL_OR_EMPTY(dtype) || NULL_OR_EMPTY(dtext)) {
    dsn->dtype = mystrdup("");
    dsn->dtext = mystrdup("");
    } else {
    dsn->dtype = mystrdup(dtype);
    dsn->dtext = mystrdup(dtext);
    }
    if (NULL_OR_EMPTY(mtype) || NULL_OR_EMPTY(mname)) {
    dsn->mtype = mystrdup("");
    dsn->mname = mystrdup("");
    } else {
    dsn->mtype = mystrdup(mtype);
    dsn->mname = mystrdup(mname);
    }
    return (dsn);
}

/* dsn_free - destroy DSN structure */

void    dsn_free(DSN *dsn)
{
    myfree((void *) dsn->status);
    myfree((void *) dsn->action);
    myfree((void *) dsn->reason);
    myfree((void *) dsn->dtype);
    myfree((void *) dsn->dtext);
    myfree((void *) dsn->mtype);
    myfree((void *) dsn->mname);
    myfree((void *) dsn);
}