OpenBSD-4.6/sbin/modload/modload.c
/* $OpenBSD: modload.c,v 1.43 2007/11/25 19:21:37 mikeb Exp $ */
/* $NetBSD: modload.c,v 1.30 2001/11/08 15:33:15 christos Exp $ */
/*
* Copyright (c) 1993 Terrence R. Lambert.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Terrence R. Lambert.
* 4. The name Terrence R. Lambert may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY TERRENCE R. LAMBERT ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE TERRENCE R. LAMBERT BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/conf.h>
#include <sys/mount.h>
#include <sys/lkm.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <nlist.h>
#include "modload.h"
#include "pathnames.h"
#define TRUE 1
#define FALSE 0
#ifndef DFLT_ENTRY
#define DFLT_ENTRY "xxxinit"
#endif /* !DFLT_ENTRY */
#ifndef DFLT_ENTRYEXT
#define DFLT_ENTRYEXT "_lkmentry"
#endif /* !DFLT_ENTRYEXT */
int debug = 0;
int verbose = 0;
char *out = NULL;
int symtab = 1;
int Sflag;
extern char *__progname;
static void cleanup(void);
/* prelink the module */
static int
prelink(const char *kernel, const char *entry, const char *outfile,
const void *address, const char *object)
{
char cmdbuf[1024];
int fd;
linkcmd(cmdbuf, sizeof(cmdbuf),
kernel, entry, outfile, address, object);
if (debug)
fprintf(stderr, "%s\n", cmdbuf);
if ((fd = open(kernel, O_RDONLY)) == -1)
errx(1, "can't open %s\n%s: please specify alternative kernel "
"executable with -A option", kernel, __progname);
else
close(fd);
if (system(cmdbuf) != 0)
return (1);
return (0);
}
static void
usage(void)
{
fprintf(stderr, "usage: %s [-dnSsv] [-A kernel] [-e entry]\n",
__progname);
fprintf(stderr, "\t[-o output_file] [-p postinstall] input_file\n");
exit(1);
}
int fileopen = 0;
#define DEV_OPEN 0x01
#define MOD_OPEN 0x02
#define PART_RESRV 0x04
#define OUTFILE_CREAT 0x08
int devfd, modfd;
struct lmc_resrv resrv;
static void
cleanup(void)
{
if (fileopen & PART_RESRV) {
/*
* Free up kernel memory
*/
if (ioctl(devfd, LMUNRESRV, 0) == -1)
warn("can't release slot 0x%08x memory", resrv.slot);
}
if (fileopen & DEV_OPEN)
close(devfd);
if (fileopen & MOD_OPEN)
close(modfd);
if (fileopen & OUTFILE_CREAT)
unlink(out);
}
static int
verify_entry(const char *entry, char *filename)
{
struct nlist names[2];
int n;
char *s;
memset(names, 0, sizeof(names));
if (asprintf(&s, "_%s", entry) == -1)
err(1, "malloc");
#ifdef _AOUT_INCLUDE_
names[0].n_un.n_name = s;
#else
names[0].n_name = s;
#endif
n = nlist(filename, names);
if (n == -1)
err(1, "nlist %s", filename);
free(s);
return n;
}
/*
* Transfer data to kernel memory in chunks
* of MODIOBUF size at a time.
*/
void
loadbuf(void *buf, size_t len)
{
struct lmc_loadbuf ldbuf;
size_t n;
char *p = buf;
while (len) {
n = MIN(len, MODIOBUF);
ldbuf.cnt = n;
ldbuf.data = p;
if (ioctl(devfd, LMLOADBUF, &ldbuf) == -1)
err(11, "error loading buffer");
len -= n;
p += n;
}
}
/* Transfer some empty space. */
void
loadspace(size_t len)
{
char buf[MODIOBUF];
size_t n;
memset(buf, 0, sizeof(buf));
while (len) {
n = MIN(len, sizeof(buf));
loadbuf(buf, n);
len -= n;
}
}
/*
* Transfer symbol table to kernel memory in chunks
* of MODIOBUF size at a time.
*/
void
loadsym(void *buf, size_t len)
{
struct lmc_loadbuf ldbuf;
size_t n;
char *p = buf;
while (len) {
n = MIN(len, MODIOBUF);
ldbuf.cnt = n;
ldbuf.data = p;
if (ioctl(devfd, LMLOADSYMS, &ldbuf) == -1)
err(11, "error loading buffer");
len -= n;
p += n;
}
}
/* Transfer some empty space. */
int
main(int argc, char *argv[])
{
int strtablen, c, noready = 0, old = 0;
const char *kname = _PATH_KSYMS;
char *entry = DFLT_ENTRY;
char *post = NULL;
char *modobj;
char modout[80], *p;
struct stat stb;
size_t modsize; /* XXX */
void* modentry; /* XXX */
while ((c = getopt(argc, argv, "dnvsA:Se:p:o:")) != -1) {
switch (c) {
case 'd':
debug = 1;
break; /* debug */
case 'v':
verbose = 1;
break; /* verbose */
case 'A':
kname = optarg;
break; /* kernel */
case 'e':
entry = optarg;
break; /* entry point */
case 'p':
post = optarg;
break; /* postinstall */
case 'o':
out = optarg;
break; /* output file */
case 'n':
noready = 1;
break;
case 's':
symtab = 0;
break;
case 'S':
Sflag = 1;
break;
default:
usage();
}
}
argc -= optind;
argv += optind;
if (argc != 1)
usage();
modobj = argv[0];
atexit(cleanup);
/*
* Open the virtual device device driver for exclusive use (needed
* to write the new module to it as our means of getting it in the
* kernel).
*/
if ((devfd = open(_PATH_LKM, O_RDWR, 0)) == -1)
err(3, "%s", _PATH_LKM);
fileopen |= DEV_OPEN;
strncpy(modout, modobj, sizeof(modout) - 1);
modout[sizeof(modout) - 1] = '\0';
p = strrchr(modout, '.');
if (!p || strcmp(p, ".o"))
errx(2, "module object must end in .o");
*p = '\0';
if (out == NULL)
out = modout;
/*
* Verify that the entry point for the module exists.
*/
if (verify_entry(entry, modobj)) {
/*
* Try <modobj>_init if entry is DFLT_ENTRY.
*/
if (strcmp(entry, DFLT_ENTRY) == 0) {
if ((p = strrchr(modout, '/')))
p++;
else
p = modout;
if (asprintf(&entry, "%s%s", p, DFLT_ENTRYEXT) == -1)
err(1, "asprintf");
if (verify_entry(entry, modobj))
errx(1, "entry point _%s not found in %s",
entry, modobj);
} else
errx(1, "entry point _%s not found in %s", entry,
modobj);
}
/*
* Prelink to get file size
*/
if (prelink(kname, entry, out, 0, modobj))
errx(1, "can't prelink `%s' creating `%s'", modobj, out);
if (Sflag == 0)
fileopen |= OUTFILE_CREAT;
/*
* Pre-open the 0-linked module to get the size information
*/
if ((modfd = open(out, O_RDONLY, 0)) == -1)
err(4, "%s", out);
fileopen |= MOD_OPEN;
/*
* stat for filesize to figure out string table size
*/
if (fstat(modfd, &stb) == -1)
err(3, "fstat `%s'", out);
/*
* work out various sizes and fill in resrv bits
*/
if (mod_sizes(modfd, &modsize, &strtablen, &resrv, &stb) != 0)
err(1, "can't get module sizes");
/*
* Close the dummy module -- we have our sizing information.
*/
close(modfd);
fileopen &= ~MOD_OPEN;
/*
* Reserve the required amount of kernel memory -- this may fail
* to be successful.
*/
resrv.size = modsize; /* size in bytes */
resrv.name = modout; /* objname w/o ".o" */
resrv.slot = -1; /* returned */
resrv.addr = 0; /* returned */
if (verbose)
warnx("reserving %lu bytes of memory", (unsigned long)modsize);
if (ioctl(devfd, LMRESERV, &resrv) == -1) {
if (symtab) {
warn("not loading symbols: kernel does not support "
"symbol table loading");
}
doold:
symtab = 0;
if (ioctl(devfd, LMRESERV_O, &resrv) == -1)
err(9, "can't reserve memory");
old = TRUE;
}
fileopen |= PART_RESRV;
/*
* Relink at kernel load address
*/
if (prelink(kname, entry, out, (void*)resrv.addr, modobj))
errx(1, "can't link `%s' creating `%s' bound to %p",
modobj, out, (void*)resrv.addr);
/*
* Open the relinked module to load it...
*/
if ((modfd = open(out, O_RDONLY, 0)) == -1)
err(4, "%s", out);
fileopen |= MOD_OPEN;
modentry = mod_load(modfd);
if (debug)
(void)fprintf(stderr, "modentry = %p\n", modentry);
if (symtab)
mod_symload(strtablen);
/*
* Save ourselves before disaster (potentitally) strikes...
*/
sync();
if (noready)
return 0;
/*
* Trigger the module as loaded by calling the entry procedure;
* this will do all necessary table fixup to ensure that state
* is maintained on success, or blow everything back to ground
* zero on failure.
*/
if (ioctl(devfd, LMREADY, &modentry) == -1) {
if (errno == EINVAL && !old) {
if (fileopen & MOD_OPEN)
close(modfd);
/*
* PART_RESRV is not true since the kernel cleans
* up after a failed LMREADY.
*/
fileopen &= ~(MOD_OPEN|PART_RESRV);
/* try using oldstyle */
warn("module failed to load using new version; "
"trying old version");
goto doold;
} else
err(14, "error initializing module");
}
/*
* Success!
*/
fileopen &= ~PART_RESRV; /* loaded */
printf("Module loaded as ID %d\n", resrv.slot);
/*
* Execute the post-install program, if specified.
*/
if (post) {
struct lmc_stat sbuf;
char name[MAXLKMNAME] = "";
char id[16], type[32], offset[32];
sbuf.id = resrv.slot;
sbuf.name = name;
if (ioctl(devfd, LMSTAT, &sbuf) == -1)
err(15, "error fetching module stats for post-install");
(void)snprintf(id, sizeof(id), "%d", sbuf.id);
(void)snprintf(type, sizeof(type), "0x%x", sbuf.type);
(void)snprintf(offset, sizeof(offset), "%ld",
(long)sbuf.offset);
/*
* XXX
* The modload docs say that drivers can install bdevsw &
* cdevsw, but the interface only supports one at a time.
*/
execl(post, post, id, type, offset, (char *)NULL);
err(16, "can't exec `%s'", post);
}
exit (0);
}