postconf_edit.c

[詳解]

/*++
/* NAME
/*  postconf_edit 3
/* SUMMARY
/*  edit main.cf or master.cf
/* SYNOPSIS
/*  #include <postconf.h>
/*
/*  void    pcf_edit_main(mode, argc, argv)
/*  int mode;
/*  int argc;
/*  char    **argv;
/*
/*  void    pcf_edit_master(mode, argc, argv)
/*  int mode;
/*  int argc;
/*  char    **argv;
/* DESCRIPTION
/*  pcf_edit_main() edits the \fBmain.cf\fR configuration file.
/*  It replaces or adds parameter settings given as "\fIname=value\fR"
/*  pairs given on the command line, or removes parameter
/*  settings given as "\fIname\fR" on the command line.  The
/*  file is copied to a temporary file then renamed into place.
/*
/*  pcf_edit_master() edits the \fBmaster.cf\fR configuration
/*  file.  The file is copied to a temporary file then renamed
/*  into place. Depending on the flags in \fBmode\fR:
/* .IP PCF_MASTER_ENTRY
/*  With PCF_EDIT_CONF, pcf_edit_master() replaces or adds
/*  entire master.cf entries, specified on the command line as
/*  "\fIname/type = name type private unprivileged chroot wakeup
/*  process_limit command...\fR".
/*
/*  With PCF_EDIT_EXCL or PCF_COMMENT_OUT, pcf_edit_master()
/*  removes or comments out entries specified on the command
/*  line as "\fIname/type\fR.
/* .IP PCF_MASTER_FLD
/*  With PCF_EDIT_CONF, pcf_edit_master() replaces the value
/*  of specific service attributes, specified on the command
/*  line as "\fIname/type/attribute = value\fR".
/* .IP PCF_MASTER_PARAM
/*  With PCF_EDIT_CONF, pcf_edit_master() replaces or adds the
/*  value of service parameters, specified on the command line
/*  as "\fIname/type/parameter = value\fR".
/*
/*  With PCF_EDIT_EXCL, pcf_edit_master() removes service
/*  parameters specified on the command line as "\fIparametername\fR".
/* DIAGNOSTICS
/*  Problems are reported to the standard error stream.
/* FILES
/*  /etc/postfix/main.cf, Postfix configuration parameters
/*  /etc/postfix/main.cf.tmp, temporary name
/*  /etc/postfix/master.cf, Postfix configuration parameters
/*  /etc/postfix/master.cf.tmp, temporary name
/* 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 <string.h>
#include <ctype.h>

/* Utility library. */

#include <msg.h>
#include <mymalloc.h>
#include <htable.h>
#include <vstring.h>
#include <vstring_vstream.h>
#include <edit_file.h>
#include <readlline.h>
#include <stringops.h>
#include <split_at.h>

/* Global library. */

#include <mail_params.h>

/* Application-specific. */

#include <postconf.h>

#define STR(x) vstring_str(x)

/* pcf_find_cf_info - pass-through non-content line, return content or null */

static char *pcf_find_cf_info(VSTRING *buf, VSTREAM *dst)
{
    char   *cp;

    for (cp = STR(buf); ISSPACE(*cp) /* including newline */ ; cp++)
     /* void */ ;
    /* Pass-through comment, all-whitespace, or empty line. */
    if (*cp == '#' || *cp == 0) {
    vstream_fputs(STR(buf), dst);
    return (0);
    } else {
    return (cp);
    }
}

/* pcf_next_cf_line - return next content line, pass non-content */

static char *pcf_next_cf_line(VSTRING *buf, VSTREAM *src, VSTREAM *dst, int *lineno)
{
    char   *cp;

    while (vstring_get(buf, src) != VSTREAM_EOF) {
    if (lineno)
        *lineno += 1;
    if ((cp = pcf_find_cf_info(buf, dst)) != 0)
        return (cp);
    }
    return (0);
}

/* pcf_gobble_cf_line - accumulate multi-line content, pass non-content */

static void pcf_gobble_cf_line(VSTRING *full_entry_buf, VSTRING *line_buf,
                        VSTREAM *src, VSTREAM *dst, int *lineno)
{
    int     ch;

    vstring_strcpy(full_entry_buf, STR(line_buf));
    for (;;) {
    if ((ch = VSTREAM_GETC(src)) != VSTREAM_EOF)
        vstream_ungetc(src, ch);
    if ((ch != '#' && !ISSPACE(ch))
        || vstring_get(line_buf, src) == VSTREAM_EOF)
        break;
    lineno += 1;
    if (pcf_find_cf_info(line_buf, dst))
        vstring_strcat(full_entry_buf, STR(line_buf));
    }
}

/* pcf_edit_main - edit main.cf file */

void    pcf_edit_main(int mode, int argc, char **argv)
{
    char   *path;
    EDIT_FILE *ep;
    VSTREAM *src;
    VSTREAM *dst;
    VSTRING *buf = vstring_alloc(100);
    VSTRING *key = vstring_alloc(10);
    char   *cp;
    char   *pattern;
    char   *edit_value;
    HTABLE *table;
    struct cvalue {
    char   *value;
    int     found;
    };
    struct cvalue *cvalue;
    HTABLE_INFO **ht_info;
    HTABLE_INFO **ht;
    int     interesting;
    const char *err;

    /*
     * Store command-line parameters for quick lookup.
     */
    table = htable_create(argc);
    while ((cp = *argv++) != 0) {
    if (strchr(cp, '\n') != 0)
        msg_fatal("-e, -X, or -# accepts no multi-line input");
    while (ISSPACE(*cp))
        cp++;
    if (*cp == '#')
        msg_fatal("-e, -X, or -# accepts no comment input");
    if (mode & PCF_EDIT_CONF) {
        if ((err = split_nameval(cp, &pattern, &edit_value)) != 0)
        msg_fatal("%s: \"%s\"", err, cp);
    } else if (mode & (PCF_COMMENT_OUT | PCF_EDIT_EXCL)) {
        if (*cp == 0)
        msg_fatal("-X or -# requires non-blank parameter names");
        if (strchr(cp, '=') != 0)
        msg_fatal("-X or -# requires parameter names without value");
        pattern = cp;
        trimblanks(pattern, 0);
        edit_value = 0;
    } else {
        msg_panic("pcf_edit_main: unknown mode %d", mode);
    }
    cvalue = (struct cvalue *) mymalloc(sizeof(*cvalue));
    cvalue->value = edit_value;
    cvalue->found = 0;
    htable_enter(table, pattern, (void *) cvalue);
    }

    /*
     * Open a temp file for the result. This uses a deterministic name so we
     * don't leave behind thrash with random names.
     */
    pcf_set_config_dir();
    path = concatenate(var_config_dir, "/", MAIN_CONF_FILE, (char *) 0);
    if ((ep = edit_file_open(path, O_CREAT | O_WRONLY, 0644)) == 0)
    msg_fatal("open %s%s: %m", path, EDIT_FILE_SUFFIX);
    dst = ep->tmp_fp;

    /*
     * Open the original file for input.
     */
    if ((src = vstream_fopen(path, O_RDONLY, 0)) == 0) {
    /* OK to delete, since we control the temp file name exclusively. */
    (void) unlink(ep->tmp_path);
    msg_fatal("open %s for reading: %m", path);
    }

    /*
     * Copy original file to temp file, while replacing parameters on the
     * fly. Issue warnings for names found multiple times.
     */
#define STR(x) vstring_str(x)

    interesting = 0;
    while ((cp = pcf_next_cf_line(buf, src, dst, (int *) 0)) != 0) {
    /* Copy, skip or replace continued text. */
    if (cp > STR(buf)) {
        if (interesting == 0)
        vstream_fputs(STR(buf), dst);
        else if (mode & PCF_COMMENT_OUT)
        vstream_fprintf(dst, "#%s", STR(buf));
    }
    /* Copy or replace start of logical line. */
    else {
        vstring_strncpy(key, cp, strcspn(cp, CHARS_SPACE "="));
        cvalue = (struct cvalue *) htable_find(table, STR(key));
        if ((interesting = !!cvalue) != 0) {
        if (cvalue->found++ == 1)
            msg_warn("%s: multiple entries for \"%s\"", path, STR(key));
        if (mode & PCF_EDIT_CONF)
            vstream_fprintf(dst, "%s = %s\n", STR(key), cvalue->value);
        else if (mode & PCF_COMMENT_OUT)
            vstream_fprintf(dst, "#%s", cp);
        } else {
        vstream_fputs(STR(buf), dst);
        }
    }
    }

    /*
     * Generate new entries for parameters that were not found.
     */
    if (mode & PCF_EDIT_CONF) {
    for (ht_info = ht = htable_list(table); *ht; ht++) {
        cvalue = (struct cvalue *) ht[0]->value;
        if (cvalue->found == 0)
        vstream_fprintf(dst, "%s = %s\n", ht[0]->key, cvalue->value);
    }
    myfree((void *) ht_info);
    }

    /*
     * When all is well, rename the temp file to the original one.
     */
    if (vstream_fclose(src))
    msg_fatal("read %s: %m", path);
    if (edit_file_close(ep) != 0)
    msg_fatal("close %s%s: %m", path, EDIT_FILE_SUFFIX);

    /*
     * Cleanup.
     */
    myfree(path);
    vstring_free(buf);
    vstring_free(key);
    htable_free(table, myfree);
}

 /*
  * Data structure to hold a master.cf edit request.
  */
typedef struct {
    int     match_count;        /* hit count */
    const char *raw_text;       /* unparsed command-line argument */
    char   *parsed_text;        /* destructive parse */
    ARGV   *service_pattern;        /* service name, type, ... */
    int     field_number;       /* attribute field number */
    const char *param_pattern;      /* parameter name */
    char   *edit_value;         /* value substring */
} PCF_MASTER_EDIT_REQ;

/* pcf_edit_master - edit master.cf file */

void    pcf_edit_master(int mode, int argc, char **argv)
{
    const char *myname = "pcf_edit_master";
    char   *path;
    EDIT_FILE *ep;
    VSTREAM *src;
    VSTREAM *dst;
    VSTRING *line_buf = vstring_alloc(100);
    VSTRING *parse_buf = vstring_alloc(100);
    int     lineno;
    PCF_MASTER_ENT *new_entry;
    VSTRING *full_entry_buf = vstring_alloc(100);
    char   *cp;
    char   *pattern;
    int     service_name_type_matched;
    const char *err;
    PCF_MASTER_EDIT_REQ *edit_reqs;
    PCF_MASTER_EDIT_REQ *req;
    int     num_reqs = argc;
    const char *edit_opts = "-Me, -Fe, -Pe, -X, or -#";
    char   *service_name;
    char   *service_type;

    /*
     * Sanity check.
     */
    if (num_reqs <= 0)
    msg_panic("%s: empty argument list", myname);

    /*
     * Preprocessing: split pattern=value, then split the pattern components.
     */
    edit_reqs = (PCF_MASTER_EDIT_REQ *) mymalloc(sizeof(*edit_reqs) * num_reqs);
    for (req = edit_reqs; *argv != 0; req++, argv++) {
    req->match_count = 0;
    req->raw_text = *argv;
    cp = req->parsed_text = mystrdup(req->raw_text);
    if (strchr(cp, '\n') != 0)
        msg_fatal("%s accept no multi-line input", edit_opts);
    while (ISSPACE(*cp))
        cp++;
    if (*cp == '#')
        msg_fatal("%s accept no comment input", edit_opts);
    /* Separate the pattern from the value. */
    if (mode & PCF_EDIT_CONF) {
        if ((err = split_nameval(cp, &pattern, &req->edit_value)) != 0)
        msg_fatal("%s: \"%s\"", err, req->raw_text);
#if 0
        if ((mode & PCF_MASTER_PARAM)
        && req->edit_value[strcspn(req->edit_value, PCF_MASTER_BLANKS)])
        msg_fatal("whitespace in parameter value: \"%s\"",
              req->raw_text);
#endif
    } else if (mode & (PCF_COMMENT_OUT | PCF_EDIT_EXCL)) {
        if (strchr(cp, '=') != 0)
        msg_fatal("-X or -# requires names without value");
        pattern = cp;
        trimblanks(pattern, 0);
        req->edit_value = 0;
    } else {
        msg_panic("%s: unknown mode %d", myname, mode);
    }

#define PCF_MASTER_MASK (PCF_MASTER_ENTRY | PCF_MASTER_FLD | PCF_MASTER_PARAM)

    /*
     * Split name/type or name/type/whatever pattern into components.
     */
    switch (mode & PCF_MASTER_MASK) {
    case PCF_MASTER_ENTRY:
        if ((req->service_pattern =
         pcf_parse_service_pattern(pattern, 2, 2)) == 0)
        msg_fatal("-Me, -MX or -M# requires service_name/type");
        break;
    case PCF_MASTER_FLD:
        if ((req->service_pattern =
         pcf_parse_service_pattern(pattern, 3, 3)) == 0)
        msg_fatal("-Fe or -FX requires service_name/type/field_name");
        req->field_number =
        pcf_parse_field_pattern(req->service_pattern->argv[2]);
        if (pcf_is_magic_field_pattern(req->field_number))
        msg_fatal("-Fe does not accept wild-card field name");
        if ((mode & PCF_EDIT_CONF)
        && req->field_number < PCF_MASTER_FLD_CMD
        && req->edit_value[strcspn(req->edit_value, PCF_MASTER_BLANKS)])
        msg_fatal("-Fe does not accept whitespace in non-command field");
        break;
    case PCF_MASTER_PARAM:
        if ((req->service_pattern =
         pcf_parse_service_pattern(pattern, 3, 3)) == 0)
        msg_fatal("-Pe or -PX requires service_name/type/parameter");
        req->param_pattern = req->service_pattern->argv[2];
        if (PCF_IS_MAGIC_PARAM_PATTERN(req->param_pattern))
        msg_fatal("-Pe does not accept wild-card parameter name");
        if ((mode & PCF_EDIT_CONF)
        && req->edit_value[strcspn(req->edit_value, PCF_MASTER_BLANKS)])
        msg_fatal("-Pe does not accept whitespace in parameter value");
        break;
    default:
        msg_panic("%s: unknown edit mode %d", myname, mode);
    }
    }

    /*
     * Open a temp file for the result. This uses a deterministic name so we
     * don't leave behind thrash with random names.
     */
    pcf_set_config_dir();
    path = concatenate(var_config_dir, "/", MASTER_CONF_FILE, (char *) 0);
    if ((ep = edit_file_open(path, O_CREAT | O_WRONLY, 0644)) == 0)
    msg_fatal("open %s%s: %m", path, EDIT_FILE_SUFFIX);
    dst = ep->tmp_fp;

    /*
     * Open the original file for input.
     */
    if ((src = vstream_fopen(path, O_RDONLY, 0)) == 0) {
    /* OK to delete, since we control the temp file name exclusively. */
    (void) unlink(ep->tmp_path);
    msg_fatal("open %s for reading: %m", path);
    }

    /*
     * Copy original file to temp file, while replacing service entries on
     * the fly.
     */
    service_name_type_matched = 0;
    new_entry = 0;
    lineno = 0;
    while ((cp = pcf_next_cf_line(parse_buf, src, dst, &lineno)) != 0) {
    vstring_strcpy(line_buf, STR(parse_buf));

    /*
     * Copy, skip or replace continued text.
     */
    if (cp > STR(parse_buf)) {
        if (service_name_type_matched == 0)
        vstream_fputs(STR(line_buf), dst);
        else if (mode & PCF_COMMENT_OUT)
        vstream_fprintf(dst, "#%s", STR(line_buf));
    }

    /*
     * Copy or replace (start of) logical line.
     */
    else {
        service_name_type_matched = 0;

        /*
         * Parse out the service name and type.
         */
        if ((service_name = mystrtok(&cp, PCF_MASTER_BLANKS)) == 0
        || (service_type = mystrtok(&cp, PCF_MASTER_BLANKS)) == 0)
        msg_fatal("file %s: line %d: specify service name and type "
              "on the same line", path, lineno);
        if (strchr(service_name, '='))
        msg_fatal("file %s: line %d: service name syntax \"%s\" is "
              "unsupported with %s", path, lineno, service_name,
              edit_opts);
        if (service_type[strcspn(service_type, "=/")] != 0)
        msg_fatal("file %s: line %d: "
            "service type syntax \"%s\" is unsupported with %s",
              path, lineno, service_type, edit_opts);

        /*
         * Match each service pattern.
         */
        for (req = edit_reqs; req < edit_reqs + num_reqs; req++) {
        if (PCF_MATCH_SERVICE_PATTERN(req->service_pattern,
                          service_name,
                          service_type)) {
            service_name_type_matched = 1;  /* Sticky flag */
            req->match_count += 1;

            /*
             * Generate replacement master.cf entries.
             */
            if ((mode & PCF_EDIT_CONF)
            || ((mode & PCF_MASTER_PARAM) && (mode & PCF_EDIT_EXCL))) {
            switch (mode & PCF_MASTER_MASK) {

                /*
                 * Replace master.cf entry field or parameter
                 * value.
                 */
            case PCF_MASTER_FLD:
            case PCF_MASTER_PARAM:
                if (new_entry == 0) {
                /* Gobble up any continuation lines. */
                pcf_gobble_cf_line(full_entry_buf, line_buf,
                           src, dst, &lineno);
                new_entry = (PCF_MASTER_ENT *)
                    mymalloc(sizeof(*new_entry));
                if ((err = pcf_parse_master_entry(new_entry,
                         STR(full_entry_buf))) != 0)
                    msg_fatal("file %s: line %d: %s",
                          path, lineno, err);
                }
                if (mode & PCF_MASTER_FLD) {
                pcf_edit_master_field(new_entry,
                              req->field_number,
                              req->edit_value);
                } else {
                pcf_edit_master_param(new_entry, mode,
                              req->param_pattern,
                              req->edit_value);
                }
                break;

                /*
                 * Replace entire master.cf entry.
                 */
            case PCF_MASTER_ENTRY:
                if (new_entry != 0)
                pcf_free_master_entry(new_entry);
                new_entry = (PCF_MASTER_ENT *)
                mymalloc(sizeof(*new_entry));
                if ((err = pcf_parse_master_entry(new_entry,
                             req->edit_value)) != 0)
                msg_fatal("%s: \"%s\"", err, req->raw_text);
                break;
            default:
                msg_panic("%s: unknown edit mode %d", myname, mode);
            }
            }
        }
        }

        /*
         * Pass through or replace the current input line.
         */
        if (new_entry) {
        pcf_print_master_entry(dst, PCF_FOLD_LINE, new_entry);
        pcf_free_master_entry(new_entry);
        new_entry = 0;
        } else if (service_name_type_matched == 0) {
        vstream_fputs(STR(line_buf), dst);
        } else if (mode & PCF_COMMENT_OUT) {
        vstream_fprintf(dst, "#%s", STR(line_buf));
        }
    }
    }

    /*
     * Postprocessing: when editing entire service entries, generate new
     * entries for services not found. Otherwise (editing fields or
     * parameters), "service not found" is a fatal error.
     */
    for (req = edit_reqs; req < edit_reqs + num_reqs; req++) {
    if (req->match_count == 0) {
        if ((mode & PCF_MASTER_ENTRY) && (mode & PCF_EDIT_CONF)) {
        new_entry = (PCF_MASTER_ENT *) mymalloc(sizeof(*new_entry));
        if ((err = pcf_parse_master_entry(new_entry, req->edit_value)) != 0)
            msg_fatal("%s: \"%s\"", err, req->raw_text);
        pcf_print_master_entry(dst, PCF_FOLD_LINE, new_entry);
        pcf_free_master_entry(new_entry);
        } else if ((mode & PCF_MASTER_ENTRY) == 0) {
        msg_warn("unmatched service_name/type: \"%s\"", req->raw_text);
        }
    }
    }

    /*
     * When all is well, rename the temp file to the original one.
     */
    if (vstream_fclose(src))
    msg_fatal("read %s: %m", path);
    if (edit_file_close(ep) != 0)
    msg_fatal("close %s%s: %m", path, EDIT_FILE_SUFFIX);

    /*
     * Cleanup.
     */
    myfree(path);
    vstring_free(line_buf);
    vstring_free(parse_buf);
    vstring_free(full_entry_buf);
    for (req = edit_reqs; req < edit_reqs + num_reqs; req++) {
    argv_free(req->service_pattern);
    myfree(req->parsed_text);
    }
    myfree((void *) edit_reqs);
}