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drop the LD_PRELOAD tool

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I don't have time to maintain it. And it is just a toy anyway.

Signed-off-by: Ronnie Sahlberg <ronniesahlberg@gmail.com>
This commit is contained in:
Ronnie Sahlberg
2020-02-12 15:21:03 +10:00
parent 148e5f69e8
commit e6bcdf5fdb
4 changed files with 0 additions and 749 deletions
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33
README
View File

@@ -237,39 +237,6 @@ To run the tests:
make test
LD_PRELOAD FUN
==============
There is a small LD_PRELOAD hack in the src directory that intercepts a handful
of system calls and converts iSCSI URLs to look and behave as if they are normal
read-only files.
This allows using standard UNIX tools to become iSCSI-aware with no
modifications.
For example:
The stat command: this shows the size of the iSCSI LUN as if it was a normal file:
$ LD_PRELOAD=ld_iscsi.so stat iscsi://127.0.0.1:3262/iqn.ronnie.test/2
File: `iscsi://127.0.0.1:3262/iqn.ronnie.test/2'
Size: 3431540736 Blocks: 0 IO Block: 0 regular file
Device: 0h/0d Inode: 0 Links: 0
Access: (0444/-r--r--r--) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 1970-01-01 10:00:00.000000000 +1000
Modify: 1970-01-01 10:00:00.000000000 +1000
Change: 1970-01-01 10:00:00.000000000 +1000
The cat command, which allows you to read/dump a iSCSI LUN to a file :
$ LD_PRELOAD=ld_iscsi.so cat iscsi://127.0.0.1:3262/iqn.ronnie.test/2 >copy_of_iscsi_lun
Or using dd even :
$ LD_PRELOAD=ld_iscsi.so dd if=iscsi://127.0.0.1:3262/iqn.ronnie.test/2 of=copy_of_LUN bs=10M count=1
The LD_PRELOAD hack is incomplete and needs more functions to be intercepted
before becoming fully functional. Patches welcome!
For now, it is sufficiently complete for trivial commands like stat and cat.
You probably need to implement at least lseek, pread, pwrite before it becomes
really useful.
SUPPORTED PLATFORMS
===================
libiscsi is pure POSIX and should with some tweaks run on any host that

2
configure.ac
View File

@@ -169,8 +169,6 @@ if ! test "$ac_cv_have_cunit" = yes ; then
fi
AM_CONDITIONAL(ISCSITEST, [test "$ac_cv_have_cunit" = yes -a "$enable_shared" = "yes"])
AM_CONDITIONAL(LD_ISCSI, [expr "(" "$host_os" : "linux" ")" "&" "$enable_shared" "=" "yes"])
AC_CHECK_MEMBER([struct CU_SuiteInfo.pSetUpFunc],
[AC_DEFINE([HAVE_CU_SUITEINFO_PSETUPFUNC], 1,
[Define to 1 if struct CU_SuiteInfo has a member called pSetUpFunc])],

34
examples/Makefile.am
View File

@@ -4,37 +4,3 @@ AM_CFLAGS=$(WARN_CFLAGS)
LDADD = ../lib/libiscsi.la
noinst_PROGRAMS = iscsiclient iscsi-dd
#
# LD_PRELOAD library.
#
if LD_ISCSI
EXTRA_PROGRAMS = ld_iscsi
CLEANFILES = ld_iscsi.o ld_iscsi.so lib/*
#
# This gets a bit messy:
#
# 1) let automake compile the sources
ld_iscsi_SOURCES = ld_iscsi.c
ld_iscsi_CFLAGS = $(AM_CFLAGS) -fPIC
# 2) let libtool link in the static version of the library
noinst_LTLIBRARIES = lib/libiscsi_convenience.la
lib_libiscsi_convenience_la_SOURCES = \
../lib/connect.c ../lib/iscsi-command.c ../lib/nop.c \
../lib/sync.c ../lib/crc32c.c ../lib/logging.c ../lib/pdu.c \
../lib/task_mgmt.c ../lib/discovery.c ../lib/login.c \
../lib/scsi-lowlevel.c ../lib/init.c ../lib/md5.c \
../lib/socket.c
ld_iscsi.o: ld_iscsi-ld_iscsi.o lib/libiscsi_convenience.la
$(LIBTOOL) --mode=link $(CC) -o $@ $^
# 3) Manually create the .so file.
bin_SCRIPTS = ld_iscsi.so
ld_iscsi.so: ld_iscsi.o
$(CC) -shared -o ld_iscsi.so ld_iscsi.o -ldl
endif

680
examples/ld_iscsi.c
View File

@@ -1,680 +0,0 @@
/*
Copyright (C) 2011, 2012 by Ronnie Sahlberg <ronniesahlberg@gmail.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#define _GNU_SOURCE
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <stdio.h>
#include <asm/fcntl.h>
#include "iscsi.h"
#include "iscsi-private.h"
#include "scsi-lowlevel.h"
#include <sys/syscall.h>
#include <dlfcn.h>
#include <inttypes.h>
static const char *initiator = "iqn.2007-10.com.github:sahlberg:libiscsi:ld-iscsi";
#define ISCSI_MAX_FD 255
static int debug = 0;
#define LD_ISCSI_DPRINTF(level,fmt,args...) do { if ((debug) >= level) {fprintf(stderr,"ld_iscsi: ");fprintf(stderr, (fmt), ##args); fprintf(stderr,"\n");} } while (0);
struct iscsi_fd_list {
int is_iscsi;
int dup2fd;
int in_flight;
struct iscsi_context *iscsi;
int lun;
uint32_t block_size;
uint64_t num_blocks;
off_t offset;
mode_t mode;
int get_lba_status;
struct scsi_lba_status_descriptor lbasd_cached;
int lbasd_cache_valid;
};
static struct iscsi_fd_list iscsi_fd_list[ISCSI_MAX_FD];
int (*real_open)(__const char *path, int flags, mode_t mode);
int open(const char *path, int flags, mode_t mode)
{
int fd;
if (!strncmp(path, "iscsi:", 6)) {
struct iscsi_context *iscsi;
struct iscsi_url *iscsi_url;
struct scsi_task *task;
struct scsi_readcapacity16 *rc16;
if (mode & O_NONBLOCK) {
LD_ISCSI_DPRINTF(0,"Non-blocking I/O is currently not supported");
errno = EINVAL;
return -1;
}
iscsi = iscsi_create_context(initiator);
if (iscsi == NULL) {
LD_ISCSI_DPRINTF(0,"Failed to create context");
errno = ENOMEM;
return -1;
}
iscsi_url = iscsi_parse_full_url(iscsi, path);
if (iscsi_url == NULL) {
LD_ISCSI_DPRINTF(0,"Failed to parse URL: %s\n", iscsi_get_error(iscsi));
iscsi_destroy_context(iscsi);
errno = EINVAL;
return -1;
}
iscsi_set_session_type(iscsi, ISCSI_SESSION_NORMAL);
iscsi_set_header_digest(iscsi, ISCSI_HEADER_DIGEST_NONE_CRC32C);
if (iscsi_full_connect_sync(iscsi, iscsi_url->portal, iscsi_url->lun) != 0) {
LD_ISCSI_DPRINTF(0,"Login Failed. %s\n", iscsi_get_error(iscsi));
iscsi_destroy_url(iscsi_url);
iscsi_destroy_context(iscsi);
errno = EIO;
return -1;
}
task = iscsi_readcapacity16_sync(iscsi, iscsi_url->lun);
if (task == NULL || task->status != SCSI_STATUS_GOOD) {
LD_ISCSI_DPRINTF(0,"failed to send readcapacity command");
iscsi_destroy_url(iscsi_url);
iscsi_destroy_context(iscsi);
errno = EIO;
return -1;
}
rc16 = scsi_datain_unmarshall(task);
if (rc16 == NULL) {
LD_ISCSI_DPRINTF(0,"failed to unmarshall readcapacity10 data");
scsi_free_scsi_task(task);
iscsi_destroy_url(iscsi_url);
iscsi_destroy_context(iscsi);
errno = EIO;
return -1;
}
LD_ISCSI_DPRINTF(4,"readcapacity16_sync: block_size: %d, num_blocks: %"PRIu64,rc16->block_length,rc16->returned_lba + 1);
fd = iscsi_get_fd(iscsi);
if (fd >= ISCSI_MAX_FD) {
LD_ISCSI_DPRINTF(0,"Too many files open");
iscsi_destroy_url(iscsi_url);
iscsi_destroy_context(iscsi);
errno = ENFILE;
return -1;
}
iscsi_fd_list[fd].is_iscsi = 1;
iscsi_fd_list[fd].dup2fd = -1;
iscsi_fd_list[fd].iscsi = iscsi;
iscsi_fd_list[fd].block_size = rc16->block_length;
iscsi_fd_list[fd].num_blocks = rc16->returned_lba + 1;
iscsi_fd_list[fd].offset = 0;
iscsi_fd_list[fd].lun = iscsi_url->lun;
iscsi_fd_list[fd].mode = mode;
if (getenv("LD_ISCSI_GET_LBA_STATUS") != NULL) {
iscsi_fd_list[fd].get_lba_status = atoi(getenv("LD_ISCSI_GET_LBA_STATUS"));
if (rc16->lbpme == 0){
LD_ISCSI_DPRINTF(1,"Logical unit is fully provisioned. Will skip get_lba_status tasks");
iscsi_fd_list[fd].get_lba_status = 0;
}
}
scsi_free_scsi_task(task);
iscsi_destroy_url(iscsi_url);
return fd;
}
return real_open(path, flags, mode);
}
int open64(const char *path, int flags, mode_t mode)
{
return open(path, flags | O_LARGEFILE, mode);
}
int (*real_close)(int fd);
int close(int fd)
{
if (iscsi_fd_list[fd].is_iscsi == 1) {
int i;
if (iscsi_fd_list[fd].dup2fd >= 0) {
iscsi_fd_list[fd].is_iscsi = 0;
iscsi_fd_list[fd].dup2fd = -1;
real_close(fd);
return 0;
}
/* are there any FDs dup2ed onto this ? */
for(i = 0; i < ISCSI_MAX_FD; i++) {
if (iscsi_fd_list[i].dup2fd == fd) {
break;
}
}
if (i < ISCSI_MAX_FD) {
int j;
/* yes there are DUPs onto fd, make i the new real device and repoint all other
* duplicates
*/
memcpy(&iscsi_fd_list[i], &iscsi_fd_list[fd], sizeof(struct iscsi_fd_list));
iscsi_fd_list[i].dup2fd = -1;
memset(&iscsi_fd_list[fd], 0, sizeof(struct iscsi_fd_list));
iscsi_fd_list[fd].dup2fd = -1;
iscsi_fd_list[i].iscsi->fd = i;
real_close(fd);
for(j = 0; j < ISCSI_MAX_FD; j++) {
if (j != i && iscsi_fd_list[j].dup2fd == fd) {
iscsi_fd_list[j].dup2fd = i;
}
}
return 0;
}
iscsi_fd_list[fd].is_iscsi = 0;
iscsi_fd_list[fd].dup2fd = -1;
iscsi_destroy_context(iscsi_fd_list[fd].iscsi);
iscsi_fd_list[fd].iscsi = NULL;
return 0;
}
return real_close(fd);
}
int (*real_fxstat)(int ver, int fd, struct stat *buf);
int __fxstat(int ver, int fd, struct stat *buf)
{
if (iscsi_fd_list[fd].is_iscsi == 1) {
if (iscsi_fd_list[fd].dup2fd >= 0) {
return __fxstat(ver, iscsi_fd_list[fd].dup2fd, buf);
}
memset(buf, 0, sizeof(struct stat));
buf->st_mode = S_IRUSR | S_IRGRP | S_IROTH | S_IFREG;
buf->st_size = iscsi_fd_list[fd].num_blocks * iscsi_fd_list[fd].block_size;
return 0;
}
return real_fxstat(ver, fd, buf);
}
int (*real_lxstat)(int ver, __const char *path, struct stat *buf);
int __lxstat(int ver, const char *path, struct stat *buf)
{
if (!strncmp(path, "iscsi:", 6)) {
int fd, ret;
fd = open(path, 0, 0);
if (fd == -1) {
return fd;
}
ret = __fxstat(ver, fd, buf);
close(fd);
return ret;
}
return real_lxstat(ver, path, buf);
}
int (*real_xstat)(int ver, __const char *path, struct stat *buf);
int __xstat(int ver, const char *path, struct stat *buf)
{
return __lxstat(ver, path, buf);
}
off_t (*real_lseek)(int fd, off_t offset, int whence);
off_t lseek(int fd, off_t offset, int whence) {
if (iscsi_fd_list[fd].is_iscsi == 1) {
off_t new_offset;
off_t size = iscsi_fd_list[fd].num_blocks*iscsi_fd_list[fd].block_size;
switch (whence) {
case SEEK_SET:
new_offset = offset;
break;
case SEEK_CUR:
new_offset = iscsi_fd_list[fd].offset+offset;
break;
case SEEK_END:
new_offset = size + offset;
break;
default:
errno = EINVAL;
return -1;
}
if (new_offset < 0 || new_offset > size) {
errno = EINVAL;
return -1;
}
iscsi_fd_list[fd].offset=new_offset;
return iscsi_fd_list[fd].offset;
}
return real_lseek(fd, offset, whence);
}
ssize_t (*real_read)(int fd, void *buf, size_t count);
ssize_t read(int fd, void *buf, size_t count)
{
if ((iscsi_fd_list[fd].is_iscsi == 1) && (iscsi_fd_list[fd].in_flight == 0)) {
uint64_t offset;
uint64_t num_blocks, lba;
struct scsi_task *task;
struct scsi_get_lba_status *lbas;
if (iscsi_fd_list[fd].dup2fd >= 0) {
return read(iscsi_fd_list[fd].dup2fd, buf, count);
}
offset = iscsi_fd_list[fd].offset / iscsi_fd_list[fd].block_size * iscsi_fd_list[fd].block_size;
num_blocks = (iscsi_fd_list[fd].offset - offset + count + iscsi_fd_list[fd].block_size - 1) / iscsi_fd_list[fd].block_size;
lba = offset / iscsi_fd_list[fd].block_size;
/* Don't try to read beyond the last LBA */
if (lba >= iscsi_fd_list[fd].num_blocks) {
return 0;
}
/* Trim num_blocks requested to last lba */
if ((lba + num_blocks) > iscsi_fd_list[fd].num_blocks) {
num_blocks = iscsi_fd_list[fd].num_blocks - lba;
count = num_blocks * iscsi_fd_list[fd].block_size;
}
iscsi_fd_list[fd].in_flight = 1;
if (iscsi_fd_list[fd].get_lba_status != 0) {
uint32_t i;
uint32_t _num_allocated=0;
uint32_t _num_blocks=0;
if (iscsi_fd_list[fd].lbasd_cache_valid==1) {
LD_ISCSI_DPRINTF(5,"cached get_lba_status_descriptor is lba %"PRIu64", num_blocks %d, provisioning %d",iscsi_fd_list[fd].lbasd_cached.lba,iscsi_fd_list[fd].lbasd_cached.num_blocks,iscsi_fd_list[fd].lbasd_cached.provisioning);
if (iscsi_fd_list[fd].lbasd_cached.provisioning != 0x00 && lba >= iscsi_fd_list[fd].lbasd_cached.lba && lba+num_blocks < iscsi_fd_list[fd].lbasd_cached.lba+iscsi_fd_list[fd].lbasd_cached.num_blocks)
{
LD_ISCSI_DPRINTF(4,"skipped read16_sync for non-allocated blocks: lun %d, lba %"PRIu64", num_blocks: %"PRIu64", block_size: %d, offset: %"PRIu64" count: %lu",iscsi_fd_list[fd].lun,lba,num_blocks,iscsi_fd_list[fd].block_size,offset,(unsigned long)count);
memset(buf, 0x00, count);
iscsi_fd_list[fd].offset += count;
iscsi_fd_list[fd].in_flight = 0;
return count;
}
}
LD_ISCSI_DPRINTF(4,"get_lba_status_sync: lun %d, lba %"PRIu64", num_blocks: %"PRIu64,iscsi_fd_list[fd].lun,lba,num_blocks);
task = iscsi_get_lba_status_sync(iscsi_fd_list[fd].iscsi, iscsi_fd_list[fd].lun, lba, 8+16);
if (task == NULL || task->status != SCSI_STATUS_GOOD) {
LD_ISCSI_DPRINTF(0,"failed to send get_lba_status command");
iscsi_fd_list[fd].in_flight = 0;
errno = EIO;
return -1;
}
lbas = scsi_datain_unmarshall(task);
if (lbas == NULL) {
LD_ISCSI_DPRINTF(0,"failed to unmarshall get_lba_status data");
scsi_free_scsi_task(task);
iscsi_fd_list[fd].in_flight = 0;
errno = EIO;
return -1;
}
LD_ISCSI_DPRINTF(5,"get_lba_status: num_descriptors: %d",lbas->num_descriptors);
for (i=0;i<lbas->num_descriptors;i++) {
struct scsi_lba_status_descriptor *lbasd = &lbas->descriptors[i];
LD_ISCSI_DPRINTF(5,"get_lba_status_descriptor %d, lba %"PRIu64", num_blocks %d, provisioning %d",i,lbasd->lba,lbasd->num_blocks,lbasd->provisioning);
if (lbasd->lba != _num_blocks+lba) {
LD_ISCSI_DPRINTF(0,"get_lba_status response is non-continuous");
scsi_free_scsi_task(task);
iscsi_fd_list[fd].in_flight = 0;
errno = EIO;
return -1;
}
_num_allocated+=(lbasd->provisioning==0x00)?lbasd->num_blocks:0;
_num_blocks+=lbasd->num_blocks;
iscsi_fd_list[fd].lbasd_cached=lbas->descriptors[i];
iscsi_fd_list[fd].lbasd_cache_valid=1;
}
scsi_free_scsi_task(task);
if (_num_allocated == 0 && _num_blocks >= num_blocks) {
LD_ISCSI_DPRINTF(4,"skipped read16_sync for non-allocated blocks: lun %d, lba %"PRIu64", num_blocks: %"PRIu64", block_size: %d, offset: %"PRIu64" count: %lu",iscsi_fd_list[fd].lun,lba,num_blocks,iscsi_fd_list[fd].block_size,offset,(unsigned long)count);
memset(buf, 0x00, count);
iscsi_fd_list[fd].offset += count;
iscsi_fd_list[fd].in_flight = 0;
return count;
}
}
LD_ISCSI_DPRINTF(4,"read16_sync: lun %d, lba %"PRIu64", num_blocks: %"PRIu64", block_size: %d, offset: %"PRIu64" count: %lu",iscsi_fd_list[fd].lun,lba,num_blocks,iscsi_fd_list[fd].block_size,offset,(unsigned long)count);
task = iscsi_read16_sync(iscsi_fd_list[fd].iscsi, iscsi_fd_list[fd].lun, lba, num_blocks * iscsi_fd_list[fd].block_size, iscsi_fd_list[fd].block_size, 0, 0, 0, 0, 0);
iscsi_fd_list[fd].in_flight = 0;
if (task == NULL || task->status != SCSI_STATUS_GOOD) {
LD_ISCSI_DPRINTF(0,"failed to send read16 command");
errno = EIO;
return -1;
}
memcpy(buf, &task->datain.data[iscsi_fd_list[fd].offset - offset], count);
iscsi_fd_list[fd].offset += count;
scsi_free_scsi_task(task);
return count;
}
return real_read(fd, buf, count);
}
ssize_t (*real_pread)(int fd, void *buf, size_t count, off_t offset);
ssize_t pread(int fd, void *buf, size_t count, off_t offset) {
if ((iscsi_fd_list[fd].is_iscsi == 1 && iscsi_fd_list[fd].in_flight == 0)) {
off_t old_offset;
if ((old_offset = lseek(fd, 0, SEEK_CUR)) < 0) {
errno = EIO;
return -1;
}
if (lseek(fd, offset, SEEK_SET) < 0) {
return -1;
}
if (read(fd, buf, count) < 0) {
lseek(fd, old_offset, SEEK_SET);
return -1;
}
lseek(fd, old_offset, SEEK_SET);
return count;
}
return real_pread(fd, buf, count, offset);
}
ssize_t (*real_write)(int fd, const void *buf, size_t count);
ssize_t write(int fd, const void *buf, size_t count)
{
if ((iscsi_fd_list[fd].is_iscsi == 1) && (iscsi_fd_list[fd].in_flight == 0)) {
uint64_t offset;
uint64_t num_blocks, lba;
struct scsi_task *task;
if (iscsi_fd_list[fd].dup2fd >= 0) {
return write(iscsi_fd_list[fd].dup2fd, buf, count);
}
if (iscsi_fd_list[fd].offset%iscsi_fd_list[fd].block_size) {
errno = EINVAL;
return -1;
}
if (count%iscsi_fd_list[fd].block_size) {
errno = EINVAL;
return -1;
}
iscsi_fd_list[fd].lbasd_cache_valid = 0;
offset = iscsi_fd_list[fd].offset;
num_blocks = count/iscsi_fd_list[fd].block_size;
lba = offset / iscsi_fd_list[fd].block_size;
/* Don't try to read beyond the last LBA */
if (lba >= iscsi_fd_list[fd].num_blocks) {
return 0;
}
/* Trim num_blocks requested to last lba */
if ((lba + num_blocks) > iscsi_fd_list[fd].num_blocks) {
num_blocks = iscsi_fd_list[fd].num_blocks - lba;
count = num_blocks * iscsi_fd_list[fd].block_size;
}
iscsi_fd_list[fd].in_flight = 1;
LD_ISCSI_DPRINTF(4,"write16_sync: lun %d, lba %"PRIu64", num_blocks: %"PRIu64", block_size: %d, offset: %"PRIu64" count: %lu",iscsi_fd_list[fd].lun,lba,num_blocks,iscsi_fd_list[fd].block_size,offset,(unsigned long)count);
task = iscsi_write16_sync(iscsi_fd_list[fd].iscsi, iscsi_fd_list[fd].lun, lba, (unsigned char *) buf, count, iscsi_fd_list[fd].block_size, 0, 0, 0, 0, 0);
iscsi_fd_list[fd].in_flight = 0;
if (task == NULL || task->status != SCSI_STATUS_GOOD) {
LD_ISCSI_DPRINTF(0,"failed to send write16 command");
errno = EIO;
return -1;
}
iscsi_fd_list[fd].offset += count;
scsi_free_scsi_task(task);
return count;
}
return real_write(fd, buf, count);
}
ssize_t (*real_pwrite)(int fd, const void *buf, size_t count, off_t offset);
ssize_t pwrite(int fd, const void *buf, size_t count, off_t offset) {
if ((iscsi_fd_list[fd].is_iscsi == 1 && iscsi_fd_list[fd].in_flight == 0)) {
off_t old_offset;
if ((old_offset = lseek(fd, 0, SEEK_CUR)) < 0) {
errno = EIO;
return -1;
}
if (lseek(fd, offset, SEEK_SET) < 0) {
return -1;
}
if (write(fd, buf, count) < 0) {
lseek(fd, old_offset, SEEK_SET);
return -1;
}
lseek(fd, old_offset, SEEK_SET);
return count;
}
return real_pwrite(fd, buf, count, offset);
}
int (*real_dup2)(int oldfd, int newfd);
int dup2(int oldfd, int newfd)
{
if (iscsi_fd_list[newfd].is_iscsi) {
return real_dup2(oldfd, newfd);
}
close(newfd);
if (iscsi_fd_list[oldfd].is_iscsi == 1) {
int ret;
if (iscsi_fd_list[oldfd].dup2fd >= 0) {
return dup2(iscsi_fd_list[oldfd].dup2fd, newfd);
}
ret = real_dup2(oldfd, newfd);
if (ret < 0) {
return ret;
}
iscsi_fd_list[newfd].is_iscsi = 1;
iscsi_fd_list[newfd].dup2fd = oldfd;
return newfd;
}
return real_dup2(oldfd, newfd);
}
#if defined(_LARGEFILE64_SOURCE) && _FILE_OFFSET_BITS != 64
int (*real_fxstat64)(int ver, int fd, struct stat64 *buf);
int __fxstat64(int ver, int fd, struct stat64 *buf)
{
if (iscsi_fd_list[fd].is_iscsi == 1) {
if (iscsi_fd_list[fd].dup2fd >= 0) {
return __fxstat64(ver, iscsi_fd_list[fd].dup2fd, buf);
}
memset(buf, 0, sizeof(struct stat64));
buf->st_mode = S_IRUSR | S_IRGRP | S_IROTH | S_IFREG;
buf->st_size = iscsi_fd_list[fd].num_blocks * iscsi_fd_list[fd].block_size;
return 0;
}
return real_fxstat64(ver, fd, buf);
}
int (*real_lxstat64)(int ver, __const char *path, struct stat64 *buf);
int __lxstat64(int ver, const char *path, struct stat64 *buf)
{
if (!strncmp(path, "iscsi:", 6)) {
int fd, ret;
fd = open64(path, 0, 0);
if (fd == -1) {
return fd;
}
ret = __fxstat64(ver, fd, buf);
close(fd);
return ret;
}
return real_lxstat64(ver, path, buf);
}
int (*real_xstat64)(int ver, __const char *path, struct stat64 *buf);
int __xstat64(int ver, const char *path, struct stat64 *buf)
{
return __lxstat64(ver, path, buf);
}
#endif
static void __attribute__((constructor)) _init(void)
{
int i;
for(i = 0; i < ISCSI_MAX_FD; i++) {
iscsi_fd_list[i].dup2fd = -1;
}
if (getenv("LD_ISCSI_DEBUG") != NULL) {
debug = atoi(getenv("LD_ISCSI_DEBUG"));
}
real_open = dlsym(RTLD_NEXT, "open");
if (real_open == NULL) {
LD_ISCSI_DPRINTF(0,"Failed to dlsym(open)");
exit(10);
}
real_close = dlsym(RTLD_NEXT, "close");
if (real_close == NULL) {
LD_ISCSI_DPRINTF(0,"Failed to dlsym(close)");
exit(10);
}
real_fxstat = dlsym(RTLD_NEXT, "__fxstat");
if (real_fxstat == NULL) {
LD_ISCSI_DPRINTF(0,"Failed to dlsym(__fxstat)");
exit(10);
}
real_lxstat = dlsym(RTLD_NEXT, "__lxstat");
if (real_lxstat == NULL) {
LD_ISCSI_DPRINTF(0,"Failed to dlsym(__lxstat)");
exit(10);
}
real_xstat = dlsym(RTLD_NEXT, "__xstat");
if (real_xstat == NULL) {
LD_ISCSI_DPRINTF(0,"Failed to dlsym(__xstat)");
exit(10);
}
real_lseek = dlsym(RTLD_NEXT, "lseek");
if (real_lseek == NULL) {
LD_ISCSI_DPRINTF(0,"Failed to dlsym(lseek)");
exit(10);
}
real_read = dlsym(RTLD_NEXT, "read");
if (real_read == NULL) {
LD_ISCSI_DPRINTF(0,"Failed to dlsym(read)");
exit(10);
}
real_pread = dlsym(RTLD_NEXT, "pread");
if (real_pread == NULL) {
LD_ISCSI_DPRINTF(0,"Failed to dlsym(pread)");
exit(10);
}
real_write = dlsym(RTLD_NEXT, "write");
if (real_write == NULL) {
LD_ISCSI_DPRINTF(0,"Failed to dlsym(write)");
exit(10);
}
real_pwrite = dlsym(RTLD_NEXT, "pwrite");
if (real_pwrite == NULL) {
LD_ISCSI_DPRINTF(0,"Failed to dlsym(pwrite)");
exit(10);
}
real_dup2 = dlsym(RTLD_NEXT, "dup2");
if (real_dup2 == NULL) {
LD_ISCSI_DPRINTF(0,"Failed to dlsym(dup2)");
exit(10);
}
#if defined(_LARGEFILE64_SOURCE) && _FILE_OFFSET_BITS != 64
real_fxstat64 = dlsym(RTLD_NEXT, "__fxstat64");
if (real_fxstat64 == NULL) {
LD_ISCSI_DPRINTF(0,"Failed to dlsym(__fxstat64)");
}
real_lxstat64 = dlsym(RTLD_NEXT, "__lxstat64");
if (real_lxstat64 == NULL) {
LD_ISCSI_DPRINTF(0,"Failed to dlsym(_lxstat64)");
}
real_xstat64 = dlsym(RTLD_NEXT, "__xstat64");
if (real_xstat64 == NULL) {
LD_ISCSI_DPRINTF(0,"Failed to dlsym(__xstat64)");
}
#endif
}