view rvinterf/etmsync/symlink.c @ 921:74d284add54d

fc-fsio: guard against bogus readdir results from the target If the FFS being operated on contains SE K2x0 extended filenames, readdir will return strings that are bad for printing. We need to guard against this possibility, and also against possible other bogosity that could be sent by other alien firmwares.
author Mychaela Falconia <falcon@freecalypso.org>
date Sat, 31 Dec 2022 22:55:23 +0000
parents e7502631a0f9
children
line wrap: on
line source

/*
 * Commands for experimenting with FFS symlinks
 */

#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include "etm.h"
#include "ffs.h"
#include "tmffs2.h"
#include "limits.h"
#include "ffslimits.h"
#include "localtypes.h"
#include "localstruct.h"
#include "exitcodes.h"

extern u_char rvi_msg[];
extern int rvi_msg_len;

do_symlink(target, realobj)
	char *target, *realobj;
{
	u_char cmdpkt[MAX_PKT_TO_TARGET], *dp;
	int rc, targlen, reallen;

	reallen = strlen(realobj);
	if (reallen >= TMFFS_STRING_SIZE) {
		printf("error: pathname arg exceeds string length limit\n");
		return(ERROR_USAGE);
	}
	targlen = strlen(target);
	if (3 + (reallen+2) + (targlen+2) + 1 > MAX_PKT_TO_TARGET) {
		printf("error: symlink request fails to fit into packet\n");
		return(ERROR_USAGE);
	}
	dp = cmdpkt + 1;
	*dp++ = ETM_FFS2;
	*dp++ = TMFFS_SYMLINK;
	*dp++ = reallen + 1;
	strcpy(dp, realobj);
	dp += reallen + 1;
	*dp++ = targlen + 1;
	strcpy(dp, target);
	dp += targlen + 1;
	rc = etm_pkt_exch(cmdpkt, dp - cmdpkt - 1);
	if (rc)
		return(rc);
	if (rvi_msg_len != 5) {
		printf("error: TMFFS_SYMLINK response has wrong length\n");
		return(ERROR_TARGET);
	}
	if (rvi_msg[3]) {
		report_ffs_err("symlink", rvi_msg[3]);
		return(ERROR_TARGET);
	}
	return(0);
}

cmd_symlink(argc, argv)
	char **argv;
{
	return do_symlink(argv[1], argv[2]);
}

do_readlink(pathname, databuf, rdret)
	char *pathname;
	u_char *databuf;
	int *rdret;
{
	u_char cmdpkt[MAX_PKT_TO_TARGET], *dp;
	int rc, slen, sz;

	slen = strlen(pathname);
	if (slen >= TMFFS_STRING_SIZE) {
		printf("error: pathname arg exceeds string length limit\n");
		return(ERROR_USAGE);
	}
	dp = cmdpkt + 1;
	*dp++ = ETM_FFS2;
	*dp++ = TMFFS_READLINK;
	*dp++ = slen + 1;
	strcpy(dp, pathname);
	dp += slen + 1;
	*dp++ = 0;	/* dummy 2nd buffer */
	rc = etm_pkt_exch(cmdpkt, dp - cmdpkt - 1);
	if (rc)
		return(rc);
	if (rvi_msg[3]) {
		report_ffs_err("readlink", rvi_msg[3]);
		return(ERROR_TARGET);
	}
	if (rvi_msg_len < 6) {
		*rdret = 0;
		return(0);
	}
	sz = rvi_msg[4];
	if (rvi_msg_len != sz + 6) {
		printf("error: readlink response has wrong length\n");
		return(ERROR_TARGET);
	}
	bcopy(rvi_msg + 5, databuf, sz);
	*rdret = sz;
	return(0);
}

cmd_readlink(argc, argv)
	char **argv;
{
	u_char databuf[256];
	int rc, sz, off, l;

	rc = do_readlink(argv[1], databuf, &sz);
	if (rc)
		return(rc);
	printf("%d bytes read\n", sz);
	for (off = 0; off < sz; off += 16) {
		l = sz - off;
		if (l > 16)
			l = 16;
		hexdump_line(off, databuf + off, l);
	}
	return(0);
}

do_readlink_sancheck(pathname, databuf)
	char *pathname;
	u_char *databuf;
{
	int rc, sz;

	rc = do_readlink(pathname, databuf, &sz);
	if (rc)
		return(rc);
	if (sz < 2 || databuf[sz-1]) {
		printf("error: readlink on %s returned garbage\n", pathname);
		return(ERROR_TARGET);
	}
	return(0);
}