cleanup_out.c

[詳解]

/*++
/* NAME
/*  cleanup_out 3
/* SUMMARY
/*  record output support
/* SYNOPSIS
/*  #include "cleanup.h"
/*
/*  int CLEANUP_OUT_OK(state)
/*  CLEANUP_STATE *state;
/*
/*  void    cleanup_out(state, type, data, len)
/*  CLEANUP_STATE *state;
/*  int type;
/*  const char *data;
/*  ssize_t len;
/*
/*  void    cleanup_out_string(state, type, str)
/*  CLEANUP_STATE *state;
/*  int type;
/*  const char *str;
/*
/*  void    CLEANUP_OUT_BUF(state, type, buf)
/*  CLEANUP_STATE *state;
/*  int type;
/*  VSTRING *buf;
/*
/*  void    cleanup_out_format(state, type, format, ...)
/*  CLEANUP_STATE *state;
/*  int type;
/*  const char *format;
/*
/*  void    cleanup_out_header(state, buf)
/*  CLEANUP_STATE *state;
/*  VSTRING *buf;
/* DESCRIPTION
/*  This module writes records to the output stream.
/*
/*  CLEANUP_OUT_OK() is a macro that evaluates to non-zero
/*  as long as it makes sense to produce output. All output
/*  routines below check for this condition.
/*
/*  cleanup_out() is the main record output routine. It writes
/*  one record of the specified type, with the specified data
/*  and length to the output stream.
/*
/*  cleanup_out_string() outputs one string as a record.
/*
/*  CLEANUP_OUT_BUF() is an unsafe macro that outputs
/*  one string buffer as a record.
/*
/*  cleanup_out_format() formats its arguments and writes
/*  the result as a record.
/*
/*  cleanup_out_header() outputs a multi-line header as records
/*  of the specified type. The input is expected to be newline
/*  separated (not newline terminated), and is modified.
/* 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>
#include <errno.h>
#include <stdlib.h>         /* 44BSD stdarg.h uses abort() */
#include <stdarg.h>
#include <string.h>

/* Utility library. */

#include <msg.h>
#include <vstring.h>
#include <vstream.h>
#include <split_at.h>
#include <stringops.h>

/* Global library. */

#include <record.h>
#include <rec_type.h>
#include <cleanup_user.h>
#include <mail_params.h>
#include <lex_822.h>
#include <smtputf8.h>

/* Application-specific. */

#include "cleanup.h"

#define STR vstring_str

/* cleanup_out - output one single record */

void    cleanup_out(CLEANUP_STATE *state, int type, const char *string, ssize_t len)
{
    int     err = 0;

    /*
     * Long message header lines have to be read and written as multiple
     * records. Other header/body content, and envelope data, is copied one
     * record at a time. Be sure to not skip a zero-length request.
     * 
     * XXX We don't know if we're writing a message header or not, but that is
     * not a problem. A REC_TYPE_NORM or REC_TYPE_CONT record can always be
     * chopped up into an equivalent set of REC_TYPE_CONT plus REC_TYPE_NORM
     * records.
     */
    if (CLEANUP_OUT_OK(state) == 0)
    return;

#define TEXT_RECORD(t)  ((t) == REC_TYPE_NORM || (t) == REC_TYPE_CONT)

    if (var_line_limit <= 0)
    msg_panic("cleanup_out: bad line length limit: %d", var_line_limit);
    do {
    if (len > var_line_limit && TEXT_RECORD(type)) {
        err = rec_put(state->dst, REC_TYPE_CONT, string, var_line_limit);
        string += var_line_limit;
        len -= var_line_limit;
    } else {
        err = rec_put(state->dst, type, string, len);
        break;
    }
    } while (len > 0 && err >= 0);

    if (err < 0) {
    if (errno == EFBIG) {
        msg_warn("%s: queue file size limit exceeded",
             state->queue_id);
        state->errs |= CLEANUP_STAT_SIZE;
    } else {
        msg_warn("%s: write queue file: %m", state->queue_id);
        state->errs |= CLEANUP_STAT_WRITE;
    }
    }
}

/* cleanup_out_string - output string to one single record */

void    cleanup_out_string(CLEANUP_STATE *state, int type, const char *string)
{
    cleanup_out(state, type, string, strlen(string));
}

/* cleanup_out_format - output one formatted record */

void    cleanup_out_format(CLEANUP_STATE *state, int type, const char *fmt,...)
{
    static VSTRING *vp;
    va_list ap;

    if (vp == 0)
    vp = vstring_alloc(100);
    va_start(ap, fmt);
    vstring_vsprintf(vp, fmt, ap);
    va_end(ap);
    CLEANUP_OUT_BUF(state, type, vp);
}

/* cleanup_out_header - output one multi-line header as a bunch of records */

void    cleanup_out_header(CLEANUP_STATE *state, VSTRING *header_buf)
{
    char   *start = vstring_str(header_buf);
    char   *line;
    char   *next_line;
    ssize_t line_len;

    /*
     * Fix 20140711: Auto-detect the presence of a non-ASCII header.
     */
    if (var_smtputf8_enable && *STR(header_buf) && !allascii(STR(header_buf))) {
    state->smtputf8 |= SMTPUTF8_FLAG_HEADER;
    /* Fix 20140713: request SMTPUTF8 support selectively. */
    if (state->flags & CLEANUP_FLAG_AUTOUTF8)
        state->smtputf8 |= SMTPUTF8_FLAG_REQUESTED;
    }

    /*
     * Prepend a tab to continued header lines that went through the address
     * rewriting machinery. See cleanup_fold_header(state) below for the form
     * of such header lines. NB: This code destroys the header. We could try
     * to avoid clobbering it, but we're not going to use the data any
     * further.
     * 
     * XXX We prefer to truncate a header at the last line boundary before the
     * header size limit. If this would undershoot the limit by more than
     * 10%, we truncate between line boundaries to avoid losing too much
     * text. This "unkind cut" may result in syntax errors and may trigger
     * warnings from down-stream MTAs.
     * 
     * If Milter is enabled, pad a short header record with a dummy record so
     * that a header record can safely be overwritten by a pointer record.
     * This simplifies header modification enormously.
     */
    for (line = start; line; line = next_line) {
    next_line = split_at(line, '\n');
    line_len = next_line ? next_line - 1 - line : strlen(line);
    if (line + line_len > start + var_header_limit) {
        if (line - start > 0.9 * var_header_limit)  /* nice cut */
        break;
        start[var_header_limit] = 0;    /* unkind cut */
        next_line = 0;
    }
    if (line == start) {
        cleanup_out_string(state, REC_TYPE_NORM, line);
        if ((state->milters || cleanup_milters)
        && line_len < REC_TYPE_PTR_PAYL_SIZE)
        rec_pad(state->dst, REC_TYPE_DTXT,
            REC_TYPE_PTR_PAYL_SIZE - line_len);
    } else if (IS_SPACE_TAB(*line)) {
        cleanup_out_string(state, REC_TYPE_NORM, line);
    } else {
        cleanup_out_format(state, REC_TYPE_NORM, "\t%s", line);
    }
    }
}