view rvinterf/etmsync/fileio.c @ 465:003e48f8ebe1

rvinterf/etmsync/fsnew.c: cast 0 to (char *) for execl sentinel I generally don't use NULL and use plain 0 instead, based on a "NULL considered harmful" discussion on the classiccmp mailing list many aeons ago (I couldn't find it, and I reason that it must have been 2005 or earlier), but a recent complaint by a packager sent me searching, and I found this: https://ewontfix.com/11/ While I don't give a @#$% about "modern" systems and code-nazi tools, I realized that passing a plain 0 as a pointer sentinel in execl is wrong because it will break on systems where pointers are longer than the plain int type. Again, I don't give a @#$% about the abomination of x86_64 and the like, but if anyone ever manages to port my code to something like a PDP-11 (16-bit int, 32-bit long and pointers), then passing a plain 0 as a function argument where a pointer is expected most definitely won't work: if the most natural stack slot and SP alignment unit is 16 bits, fitting an int, with longs and pointers taking up two such slots, then the call stack will be totally wrong with a plain 0 passed for a pointer. Casting the 0 to (char *) ought to be the most kosher solution for the most retro systems possible.
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 11 Feb 2019 00:00:19 +0000
parents e7502631a0f9
children a0754c98fc2b
line wrap: on
line source

/*
 * FFS2 file descriptor I/O operations
 */

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

extern u_char rvi_msg[];
extern int rvi_msg_len;

fd_open(pathname, flags, fdrtn)
	char *pathname;
	int flags, *fdrtn;
{
	u_char cmdpkt[MAX_PKT_TO_TARGET], *dp;
	int rc, slen;

	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_OPEN;
	*dp++ = slen + 1;
	strcpy(dp, pathname);
	dp += slen + 1;
	*dp++ = flags;
	rc = etm_pkt_exch(cmdpkt, dp - cmdpkt - 1);
	if (rc)
		return(rc);
	if (rvi_msg[3]) {
		report_ffs_err("open fd", rvi_msg[3]);
		return(ERROR_TARGET);
	}
	if (rvi_msg_len != 6) {
		printf("error: open fd response has wrong length\n");
		return(ERROR_TARGET);
	}
	*fdrtn = rvi_msg[4];
	return(0);
}

fd_read(fd, databuf, rdsize, rdret)
	u_char *databuf;
	int fd, rdsize, *rdret;
{
	u_char cmdpkt[6];
	int rc, sz;

	if (rdsize > MAX_READ_DATA) {
		printf("error: # of bytes to read may not exceed %d\n",
			MAX_READ_DATA);
		return(ERROR_USAGE);
	}
	cmdpkt[1] = ETM_FFS2;
	cmdpkt[2] = TMFFS_READ;
	cmdpkt[3] = fd;
	cmdpkt[4] = rdsize;
	rc = etm_pkt_exch(cmdpkt, 4);
	if (rc)
		return(rc);
	if (rvi_msg[3]) {
		report_ffs_err("read fd", 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 || sz > rdsize) {
		printf("error: read fd response has wrong length\n");
		return(ERROR_TARGET);
	}
	bcopy(rvi_msg + 5, databuf, sz);
	*rdret = sz;
	return(0);
}

fd_write(fd, data, wrsize)
	u_char *data;
{
	u_char cmdpkt[MAX_PKT_TO_TARGET], *dp;
	int rc;

	if (wrsize > MAX_PKT_TO_TARGET - 6) {
		printf("error: fd write data fails to fit in the packet\n");
		return(ERROR_USAGE);
	}
	dp = cmdpkt + 1;
	*dp++ = ETM_FFS2;
	*dp++ = TMFFS_WRITE;
	*dp++ = fd;
	*dp++ = wrsize;
	bcopy(data, dp, wrsize);
	dp += wrsize;
	rc = etm_pkt_exch(cmdpkt, dp - cmdpkt - 1);
	if (rc)
		return(rc);
	if (rvi_msg[3]) {
		report_ffs_err("fd write", rvi_msg[3]);
		return(ERROR_TARGET);
	}
	if (rvi_msg_len != 6) {
		printf("error: TMFFS_WRITE response has wrong length\n");
		return(ERROR_TARGET);
	}
	if (rvi_msg[4] != wrsize) {
		printf("fd write error: # of bytes written != requested\n");
		return(ERROR_TARGET);
	}
	return(0);
}

fd_close(fd)
{
	u_char cmdpkt[5];
	int rc;

	cmdpkt[1] = ETM_FFS2;
	cmdpkt[2] = TMFFS_CLOSE;
	cmdpkt[3] = fd;
	rc = etm_pkt_exch(cmdpkt, 3);
	if (rc)
		return(rc);
	if (rvi_msg[3]) {
		report_ffs_err("close fd", rvi_msg[3]);
		return(ERROR_TARGET);
	}
	if (rvi_msg_len != 5) {
		printf("error: close fd response has wrong length\n");
		return(ERROR_TARGET);
	}
	return(0);
}

do_file_read(pathname, databuf, rdsize, rdret)
	char *pathname;
	u_char *databuf;
	int rdsize, *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);
	}
	if (rdsize > MAX_READ_DATA) {
		printf("error: # of bytes to read may not exceed %d\n",
			MAX_READ_DATA);
		return(ERROR_USAGE);
	}
	dp = cmdpkt + 1;
	*dp++ = ETM_FFS2;
	*dp++ = TMFFS_FILE_READ;
	*dp++ = slen + 1;
	strcpy(dp, pathname);
	dp += slen + 1;
	*dp++ = rdsize;
	rc = etm_pkt_exch(cmdpkt, dp - cmdpkt - 1);
	if (rc)
		return(rc);
	if (rvi_msg[3]) {
		report_ffs_err("read file", 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 || sz > rdsize) {
		printf("error: read file response has wrong length\n");
		return(ERROR_TARGET);
	}
	bcopy(rvi_msg + 5, databuf, sz);
	*rdret = sz;
	return(0);
}

max_short_file_write(pathname)
	char *pathname;
{
	return MAX_PKT_TO_TARGET - 3 - (strlen(pathname) + 2) - 3;
}

do_short_fwrite(pathname, data, datalen)
	char *pathname;
	u_char *data;
{
	u_char cmdpkt[MAX_PKT_TO_TARGET], *dp;
	int rc, slen;

	slen = strlen(pathname);
	if (slen >= TMFFS_STRING_SIZE) {
		printf("error: pathname arg exceeds string length limit\n");
		return(ERROR_USAGE);
	}
	if (datalen > max_short_file_write(pathname)) {
		printf("error: short write data fails to fit in the packet\n");
		return(ERROR_USAGE);
	}
	dp = cmdpkt + 1;
	*dp++ = ETM_FFS2;
	*dp++ = TMFFS_FILE_WRITE;
	*dp++ = slen + 1;
	strcpy(dp, pathname);
	dp += slen + 1;
	*dp++ = datalen;
	bcopy(data, dp, datalen);
	dp += datalen;
	*dp++ = FFS_O_CREATE | FFS_O_TRUNC;
	rc = etm_pkt_exch(cmdpkt, dp - cmdpkt - 1);
	if (rc)
		return(rc);
	if (rvi_msg_len != 5) {
		printf("error: TMFFS_FILE_WRITE response has wrong length\n");
		return(ERROR_TARGET);
	}
	if (rvi_msg[3]) {
		report_ffs_err("short file write", rvi_msg[3]);
		return(ERROR_TARGET);
	}
	return(0);
}

do_opendir(pathname, statertn, countrtn)
	char *pathname;
	u_char *statertn;
	int *countrtn;
{
	u_char cmdpkt[MAX_PKT_TO_TARGET], *dp;
	int rc, slen;

	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_OPENDIR;
	*dp++ = slen + 1;
	strcpy(dp, pathname);
	dp += slen + 1;
	rc = etm_pkt_exch(cmdpkt, dp - cmdpkt - 1);
	if (rc)
		return(rc);
	if (rvi_msg[3]) {
		report_ffs_err("opendir", rvi_msg[3]);
		return(ERROR_TARGET);
	}
	if (rvi_msg_len != 11 || rvi_msg[5] != 4) {
		printf("error: opendir response has wrong length\n");
		return(ERROR_TARGET);
	}
	*countrtn = rvi_msg[4];
	bcopy(rvi_msg + 6, statertn, 4);
	return(0);
}

do_readdir(state, namebuf, namebuflen)
	u_char *state;
	char *namebuf;
{
	u_char cmdpkt[10];
	int rc, slen;

	cmdpkt[1] = ETM_FFS2;
	cmdpkt[2] = TMFFS_READDIR;
	cmdpkt[3] = 4;
	bcopy(state, cmdpkt+4, 4);
	cmdpkt[8] = TMFFS_STRING_SIZE;
	rc = etm_pkt_exch(cmdpkt, 8);
	if (rc)
		return(rc);
	if (rvi_msg[3]) {
		report_ffs_err("readdir", rvi_msg[3]);
		return(ERROR_TARGET);
	}
	if (rvi_msg_len < 14) {
malformed:	printf("error: readdir response is malformed\n");
		return(ERROR_TARGET);
	}
	if (rvi_msg[5] != 4)
		goto malformed;
	slen = rvi_msg[10];
	if (slen < 2 || rvi_msg_len != slen + 12)
		goto malformed;
	if (slen > namebuflen) {
		printf("error: readdir response exceeds provided buffer\n");
		return(ERROR_TARGET);
	}
	if (rvi_msg[11 + slen - 1])	/* must be terminating NUL */
		goto malformed;
	bcopy(rvi_msg + 6, state, 4);
	strcpy(namebuf, rvi_msg + 11);
	return(0);
}

do_xlstat(pathname, result)
	char *pathname;
	struct stat_info *result;
{
	u_char cmdpkt[MAX_PKT_TO_TARGET], *dp;
	int rc, slen;

	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_XLSTAT;
	*dp++ = slen + 1;
	strcpy(dp, pathname);
	dp += slen + 1;
	rc = etm_pkt_exch(cmdpkt, dp - cmdpkt - 1);
	if (rc)
		return(rc);
	if (rvi_msg[3]) {
		report_ffs_err("xlstat", rvi_msg[3]);
		return(ERROR_TARGET);
	}
	if (rvi_msg_len != 30 || rvi_msg[4] != 24) {
		printf("error: xlstat response has wrong length\n");
		return(ERROR_TARGET);
	}
	result->type = rvi_msg[5];
	result->flags = rvi_msg[6];
	result->inode = rvi_msg[7] | rvi_msg[8] << 8;
	result->size = rvi_msg[9] | rvi_msg[10] << 8 | rvi_msg[11] << 16 |
			rvi_msg[12] << 24;
	result->space = rvi_msg[13] | rvi_msg[14] << 8 | rvi_msg[15] << 16 |
			rvi_msg[16] << 24;
	result->location = rvi_msg[17] | rvi_msg[18] << 8 | rvi_msg[19] << 16 |
				rvi_msg[20] << 24;
	result->block = rvi_msg[22];
	result->sequence = rvi_msg[23] | rvi_msg[24] << 8;
	result->updates = rvi_msg[25] | rvi_msg[26] << 8;
	return(0);
}

do_mkdir_existok(pathname)
	char *pathname;
{
	u_char cmdpkt[MAX_PKT_TO_TARGET], *dp;
	int rc, slen;
	struct stat_info stat;

	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_MKDIR;
	*dp++ = slen + 1;
	strcpy(dp, pathname);
	dp += slen + 1;
	rc = etm_pkt_exch(cmdpkt, dp - cmdpkt - 1);
	if (rc)
		return(rc);
	if (rvi_msg_len != 5) {
		printf("error: mkdir response has wrong length\n");
		return(ERROR_TARGET);
	}
	if (!rvi_msg[3])	/* success */
		return(0);
	if (rvi_msg[3] != TMFFS_ERR_EXISTS) {
		report_ffs_err("mkdir", rvi_msg[3]);
		return(ERROR_TARGET);
	}
	/* object already exists: OK if it's a directory, error otherwise */
	rc = do_xlstat(pathname, &stat);
	if (rc)
		return(rc);
	if (stat.type == OT_DIR)
		return(0);
	else {
		printf("error: %s exists and is not a directory\n", pathname);
		return(ERROR_TARGET);
	}
}