path: root/config.c

/*
 * mdctl - manage Linux "md" devices aka RAID arrays.
 *
 * Copyright (C) 2001 Neil Brown <neilb@cse.unsw.edu.au>
 *
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *    Author: Neil Brown
 *    Email: <neilb@cse.unsw.edu.au>
 *    Paper: Neil Brown
 *           School of Computer Science and Engineering
 *           The University of New South Wales
 *           Sydney, 2052
 *           Australia
 */

#include	"mdctl.h"
#include	"dlink.h"
#include	<glob.h>
/*
 * Read the config file
 *
 * conf_get_uuids gets a list of devicename+uuid pairs
 * conf_get_devs gets device names after expanding wildcards
 *
 * Each keeps the returned list and frees it when asked to make
 * a new list.
 *
 * The format of the config file needs to be fairly extensible.
 * Now, arrays only have names and uuids and devices merely are.
 * But later arrays might want names, and devices might want superblock
 * versions, and who knows what else.
 * I like free format, abhore backslash line continuation, adore
 *   indentation for structure and am ok about # comments.
 *
 * So, each line that isn't blank or a #comment must either start
 *  with a key word, and not be indented, or must start with a
 *  non-key-word and must be indented.
 *
 * Keywords are DEVICE and ARRAY
 * DEV{ICE} introduces some devices that might contain raid components.
 * e.g.
 *   DEV style=0 /dev/sda* /dev/hd*
 *   DEV style=1 /dev/sd[b-f]*
 * ARR{AY} describes an array giving md device and attributes like uuid=whatever
 * e.g.
 *   ARRAY /dev/md0 uuid=whatever name=something
 * Spaces separate words on each line.  Quoting, with "" or '' protects them,
 * but may not wrap over lines
 *
 */

char DefaultConfFile[] = "/etc/mdctl.conf";

char *keywords[] = { "device", "array", NULL };

/*
 * match_keyword returns an index into the keywords array, or -1 for no match
 * case is ignored, and at least three characters must be given
 */

int match_keyword(char *word)
{
    int len = strlen(word);
    int n;
    
    if (len < 3) return -1;
    for (n=0; keywords[n]; n++) {
	if (strncasecmp(word, keywords[n], len)==0)
	    return n;
    }
    return -1;
}

/* conf_word gets one word from the conf file.
 * if "allow_key", then accept words at the start of a line,
 * otherwise stop when such a word is found.
 * We assume that the file pointer is at the end of a word, so the
 * next character is a space, or a newline.  If not, it is the start of a line.
 */

char *conf_word(FILE *file, int allow_key)
{
    int wsize = 100;
    int len = 0;
    int c;
    int quote;
    int wordfound = 0;
    char *word = malloc(wsize);

    if (!word) abort();

    while (wordfound==0) {
	/* at the end of a word.. */
	c = getc(file);
	if (c == '#')
	    while (c != EOF && c != '\n')
		c = getc(file);
	if (c == EOF) break;
	if (c == '\n') continue;

	if (c != ' ' && c != '\t' && ! allow_key) {
	    ungetc(c, file);
	    break;
	}
	/* looks like it is safe to get a word here, if there is one */
	quote = 0;
	/* first, skip any spaces */
	while (c == ' ' || c == '\t')
	    c = getc(file);
	if (c != EOF && c != '\n' && c != '#') {
	    /* we really have a character of a word, so start saving it */
	    while (c != EOF && c != '\n' && (quote || (c!=' ' && c != '\t'))) {
		wordfound = 1;
		if (quote && c == quote) quote = 0;
		else if (quote == 0 && (c == '\'' || c == '"'))
		    quote = c;
		else {
		    if (len == wsize-1) {
			wsize += 100;
			word = realloc(word, wsize);
			if (!word) abort();
		    }
		    word[len++] = c;
		}
		c = getc(file);
	    }
	}
	if (c != EOF) ungetc(c, file);
    }
    word[len] = 0;
/*    printf("word is <%s>\n", word); */
    if (!wordfound) {
	free(word);
	word = NULL;
    }
    return word;
}
	
/*
 * conf_line reads one logical line from the conffile.
 * It skips comments and continues until it finds a line that starts
 * with a non blank/comment.  This character is pushed back for the next call
 * A doubly linked list of words is returned.
 * the first word will be a keyword.  Other words will have had quotes removed.
 */

char *conf_line(FILE *file)
{
    char *w;
    char *list;

    w = conf_word(file, 1);
    if (w == NULL) return NULL;

    list = dl_strdup(w);
    free(w);
    dl_init(list);

    while ((w = conf_word(file,0))){
	char *w2 = dl_strdup(w);
	free(w);
	dl_add(list, w2);
    }
/*    printf("got a line\n");*/
    return list;
}

void free_line(char *line)
{
    char *w;
    for (w=dl_next(line); w != line; w=dl_next(line)) {
	dl_del(w);
	dl_free(w);
    }
    dl_free(line);
}


struct conf_dev {
    struct conf_dev *next;
    char *name;
} *cdevlist = NULL;



int devline(char *line) 
{
    char *w;
    struct conf_dev *cd;

    for (w=dl_next(line); w != line; w=dl_next(w)) {
	if (w[0] == '/') {
	    cd = malloc(sizeof(*cd));
	    cd->name = strdup(w);
	    cd->next = cdevlist;
	    cdevlist = cd;
	} else {
	    fprintf(stderr, Name ": unreconised word on DEVICE line: %s\n",
		    w);
	}
    }
}

mddev_uuid_t uuidlist = NULL;

void arrayline(char *line)
{
    char *w;
    char *dev  = NULL;
    __u32 uuid[4];
    int uidset=0;
    mddev_uuid_t mu;

    for (w=dl_next(line); w!=line; w=dl_next(w)) {
	if (w[0] == '/') {
	    if (dev)
		fprintf(stderr, Name ": only give one device per ARRAY line: %s and %s\n",
			dev, w);
	    else dev = w;
	} else if (strncasecmp(w, "uuid=", 5)==0 ) {
	    if (uidset)
		fprintf(stderr, Name ": only specify uuid once, %s ignored.\n",
			w);
	    else {
		if (parse_uuid(w+5, uuid))
		    uidset = 1;
		else
		    fprintf(stderr, Name ": bad uuid: %s\n", w);
	    }
	} else {
	    fprintf(stderr, Name ": unrecognised word on ARRAY line: %s\n",
		    w);
	}
    }
    if (dev == NULL)
	fprintf(stderr, Name ": ARRAY line with a device\n");
    else if (uidset == 0)
	fprintf(stderr, Name ": ARRAY line %s has no uuid\n", dev);
    else {
	mu = malloc(sizeof(*mu));
	mu->devname = strdup(dev);
	memcpy(mu->uuid, uuid, sizeof(uuid));
	mu->next = uuidlist;
	uuidlist = mu;
    }
}
		    
int loaded = 0;

void load_conffile(char *conffile)
{
    FILE *f;
    char *line;

    if (loaded) return;
    if (conffile == NULL)
	conffile = DefaultConfFile;

    f = fopen(conffile, "r");
    if (f ==NULL)
	return;

    loaded = 1;
    while ((line=conf_line(f))) {
	switch(match_keyword(line)) {
	case 0: /* DEVICE */
	    devline(line);
	    break;
	case 1:
	    arrayline(line);
	    break;
	default:
	    fprintf(stderr, Name ": Unknown keyword %s\n", line);
	}
	free_line(line);
    }
    

/*    printf("got file\n"); */
}


mddev_uuid_t conf_get_uuids(char *conffile)
{
    load_conffile(conffile);
    return uuidlist;
}

mddev_dev_t conf_get_devs(char *conffile)
{
    glob_t globbuf;
    struct conf_dev *cd;
    int flags = 0;
    static mddev_dev_t dlist = NULL;
    int i;

    while (dlist) {
	mddev_dev_t t = dlist;
	dlist = dlist->next;
	free(t->devname);
	free(t);
    }
    
    load_conffile(conffile);
    
    for (cd=cdevlist; cd; cd=cd->next) {
	glob(cd->name, flags, NULL, &globbuf);
	flags |= GLOB_APPEND;
    }

    for (i=0; i<globbuf.gl_pathc; i++) {
	mddev_dev_t t = malloc(sizeof(*t));
	t->devname = strdup(globbuf.gl_pathv[i]);
	t->next = dlist;
	dlist = t;
/*	printf("one dev is %s\n", t->devname);*/
    }
    globfree(&globbuf);
    

    return dlist;
}