IABSD.fr/src/usr.sbin/hostctl/hostctl.c

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• Author : deraadt
  Date : 2019-06-28 13:32:41
  Hash : df69c215
  Message : When system calls indicate an error they return -1, not some arbitrary value < 0. errno is only updated in this case. Change all (most?) callers of syscalls to follow this better, and let's see if this strictness helps us in the future.

• usr.sbin/hostctl/hostctl.c

• /*	$OpenBSD: hostctl.c,v 1.5 2019/06/28 13:32:47 deraadt Exp $	*/
  
  /*
   * Copyright (c) 2016 Reyk Floeter <reyk@openbsd.org>
   *
   * Permission to use, copy, modify, and distribute this software for any
   * purpose with or without fee is hereby granted, provided that the above
   * copyright notice and this permission notice appear in all copies.
   *
   * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
   * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
   * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
   * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
   * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
   */
  
  #include <sys/ioctl.h>
  #include <sys/types.h>
  
  #include <dev/pv/pvvar.h>
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <unistd.h>
  #include <fcntl.h>
  #include <errno.h>
  #include <err.h>
  #include <vis.h>
  
  #define KVBUFSZ	 4096				/* arbitrary value */
  
  char		*path_pvbus = "/dev/pvbus0";	/* the first hv interface */
  int		 qflag = 0;			/* quiet */
  int		 tflag = 0;			/* show type */
  
  __dead void	 usage(void);
  int		 kvsetstr(char *, const char *, size_t);
  int		 kvsetfile(char *, const char *, size_t);
  
  __dead void
  usage(void)
  {
  	extern char	*__progname;
  	fprintf(stderr, "usage: %s [-qt] [-f device] "
  	    "[-i input] [-o output] key [value]\n", __progname);
  	exit(1);
  }
  
  int
  kvsetstr(char *dst, const char *src, size_t dstlen)
  {
  	size_t	sz;
  
  	/* Sanitize the string before sending it to the kernel and host */
  	if ((sz = strnvis(dst, src, dstlen, VIS_SAFE | VIS_CSTYLE)) >= dstlen)
  		return (-1);
  
  	/* Remove trailing newline */
  	dst[strcspn(dst, "\n")] = '\0';
  
  	return (0);
  }
  
  int
  kvsetfile(char *dst, const char *input, size_t dstlen)
  {
  	char	*buf = NULL;
  	int	 ret = -1;
  	FILE	*fp;
  
  	if (strcmp("-", input) == 0)
  		fp = stdin;
  	else if ((fp = fopen(input, "r")) == NULL)
  		return (-1);
  
  	if ((buf = calloc(1, dstlen)) == NULL)
  		goto done;
  	if (fread(buf, 1, dstlen - 1, fp) == 0)
  		goto done;
  	if (kvsetstr(dst, buf, dstlen) == -1)
  		goto done;
  
  	ret = 0;
   done:
  	free(buf);
  	if (fp != stdin)
  		fclose(fp);
  	return (ret);
  }
  
  int
  main(int argc, char *argv[])
  {
  	const char		*key, *value, *in = NULL, *out = NULL;
  	FILE			*outfp = stdout;
  	int			fd, ret;
  	struct pvbus_req	pvr;
  	int			ch;
  	unsigned long		cmd = 0;
  	char			*str;
  
  	while ((ch = getopt(argc, argv, "f:i:o:qt")) != -1) {
  		switch (ch) {
  		case 'f':
  			path_pvbus = optarg;
  			break;
  		case 'i':
  			in = optarg;
  			break;
  		case 'o':
  			out = optarg;
  			break;
  		case 'q':
  			qflag++;
  			break;
  		case 't':
  			tflag++;
  			break;
  		default:
  			usage();
  		}
  	}
  	argc -= optind;
  	argv += optind;
  
  	if ((fd = open(path_pvbus, O_RDONLY)) == -1)
  		err(1, "open: %s", path_pvbus);
  
  	if (out != NULL) {
  		if (strcmp("-", out) == 0)
  			outfp = stdout;
  		else if ((outfp = fopen(out, "w")) == NULL)
  			err(1, "fopen: %s", out);
  	}
  
  	memset(&pvr, 0, sizeof(pvr));
  	pvr.pvr_keylen = pvr.pvr_valuelen = KVBUFSZ;
  	if ((pvr.pvr_key = calloc(1, pvr.pvr_keylen)) == NULL ||
  	    (pvr.pvr_value = calloc(1, pvr.pvr_valuelen)) == NULL)
  		err(1, "calloc");
  
  	if (tflag) {
  		if (ioctl(fd, PVBUSIOC_TYPE, &pvr, sizeof(pvr)) == -1)
  			err(1, "ioctl");
  
  		/* The returned type should be a simple single-line key */
  		if (stravis(&str, pvr.pvr_key,
  		    VIS_WHITE | VIS_DQ | VIS_CSTYLE) == -1)
  			err(1, "stravis");
  		fprintf(outfp, "%s: %s\n", path_pvbus, str);
  		free(str);
  		goto done;
  	}
  
  	if (argc < 1)
  		usage();
  	key = argv[0];
  
  	if (kvsetstr(pvr.pvr_key, key, pvr.pvr_keylen) == -1)
  		errx(1, "key too long");
  
  	/* Validate command line options for reading or writing */
  	if (argc == 2 && in == NULL) {
  		cmd = PVBUSIOC_KVWRITE;
  		value = argv[1];
  		if (kvsetstr(pvr.pvr_value, value, pvr.pvr_valuelen) == -1)
  			errx(1, "value too long");
  	} else if (argc == 1 && in != NULL) {
  		cmd = PVBUSIOC_KVWRITE;
  		if (kvsetfile(pvr.pvr_value, in, pvr.pvr_valuelen) == -1)
  			errx(1, "input file");
  	} else if (argc == 1) {
  		cmd = cmd == 0 ? PVBUSIOC_KVREAD : cmd;
  	} else
  		usage();
  
  	/* Re-open read-writable */
  	if (cmd == PVBUSIOC_KVWRITE) {
  		close(fd);
  		if ((fd = open(path_pvbus, O_RDWR)) == -1)
  			err(1, "open: %s", path_pvbus);
  	}
  
  	if ((ret = ioctl(fd, cmd, &pvr, sizeof(pvr))) == -1)
  		err(1, "ioctl");
  
  	if (!qflag && strlen(pvr.pvr_value)) {
  		/*
  		 * The value can contain newlines and basically anything;
  		 * only encode the unsafe characters that could perform
  		 * unexpected functions on the terminal.
  		 */
  		if (stravis(&str, pvr.pvr_value, VIS_SAFE | VIS_CSTYLE) == -1)
  			err(1, "stravis");
  		fprintf(outfp, "%s\n", str);
  		free(str);
  	}
  
   done:
  	if (outfp != stdout)
  		fclose(outfp);
  	free(pvr.pvr_value);
  	free(pvr.pvr_key);
  	close(fd);
  
  	return (0);
  }