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vm: verify files copied with qvm-copy-to-vm using crc32

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Additionally this introduces notification for qfile-agent when remote end
finished file writing.
This commit is contained in:
Marek Marczykowski 2011-05-26 00:12:14 +02:00
parent 54d6be0dd4
commit 449e99d2aa
7 changed files with 235 additions and 12 deletions
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4
appvm/Makefile
View File

@ -5,9 +5,9 @@ dvm_file_editor: dvm_file_editor.o ../common/ioall.o
$(CC) -pie -g -o $@ $^
qfile-agent-dvm: qfile-agent-dvm.o ../common/ioall.o ../common/gui-fatal.o
$(CC) -pie -g -o $@ $^
qfile-agent: qfile-agent.o ../common/ioall.o ../common/gui-fatal.o copy_file.o
qfile-agent: qfile-agent.o ../common/ioall.o ../common/gui-fatal.o copy_file.o crc32.o
$(CC) -pie -g -o $@ $^
qfile-unpacker: qfile-unpacker.o ../common/ioall.o ../common/gui-fatal.o copy_file.o unpack.o
qfile-unpacker: qfile-unpacker.o ../common/ioall.o ../common/gui-fatal.o copy_file.o unpack.o crc32.o
$(CC) -pie -g -o $@ $^
clean:

6
appvm/copy_file.c
View File

@ -1,10 +1,11 @@
#include <unistd.h>
#include <ioall.h>
#include "filecopy.h"
#include "crc32.h"
extern void notify_progress(int, int);
int copy_file(int outfd, int infd, long long size)
int copy_file(int outfd, int infd, long long size, unsigned long *crc32)
{
char buf[4096];
long long written = 0;
@ -20,6 +21,9 @@ int copy_file(int outfd, int infd, long long size)
return COPY_FILE_READ_EOF;
if (ret < 0)
return COPY_FILE_READ_ERROR;
/* acumulate crc32 if requested */
if (crc32)
*crc32 = Crc32_ComputeBuf(*crc32, buf, ret);
if (!write_all(outfd, buf, ret))
return COPY_FILE_WRITE_ERROR;
notify_progress(ret, 0);

146
appvm/crc32.c Normal file
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@ -0,0 +1,146 @@
/*----------------------------------------------------------------------------*\
* CRC-32 version 2.0.0 by Craig Bruce, 2006-04-29.
*
* This program generates the CRC-32 values for the files named in the
* command-line arguments. These are the same CRC-32 values used by GZIP,
* PKZIP, and ZMODEM. The Crc32_ComputeBuf() can also be detached and
* used independently.
*
* THIS PROGRAM IS PUBLIC-DOMAIN SOFTWARE.
*
* Based on the byte-oriented implementation "File Verification Using CRC"
* by Mark R. Nelson in Dr. Dobb's Journal, May 1992, pp. 64-67.
*
* v1.0.0: original release.
* v1.0.1: fixed printf formats.
* v1.0.2: fixed something else.
* v1.0.3: replaced CRC constant table by generator function.
* v1.0.4: reformatted code, made ANSI C. 1994-12-05.
* v2.0.0: rewrote to use memory buffer & static table, 2006-04-29.
\*----------------------------------------------------------------------------*/
#include <stdio.h>
#include <stdlib.h>
/*----------------------------------------------------------------------------*\
* Local functions
\*----------------------------------------------------------------------------*/
unsigned long Crc32_ComputeBuf( unsigned long inCrc32, const void *buf,
size_t bufLen );
/*----------------------------------------------------------------------------*\
* NAME:
* Crc32_ComputeFile() - compute CRC-32 value for a file
* DESCRIPTION:
* Computes the CRC-32 value for an opened file.
* ARGUMENTS:
* file - file pointer
* outCrc32 - (out) result CRC-32 value
* RETURNS:
* err - 0 on success or -1 on error
* ERRORS:
* - file errors
\*----------------------------------------------------------------------------*/
int Crc32_ComputeFile( FILE *file, unsigned long *outCrc32 )
{
# define CRC_BUFFER_SIZE 8192
unsigned char buf[CRC_BUFFER_SIZE];
size_t bufLen;
/** accumulate crc32 from file **/
*outCrc32 = 0;
while (1) {
bufLen = fread( buf, 1, CRC_BUFFER_SIZE, file );
if (bufLen == 0) {
if (ferror(file)) {
fprintf( stderr, "error reading file\n" );
goto ERR_EXIT;
}
break;
}
*outCrc32 = Crc32_ComputeBuf( *outCrc32, buf, bufLen );
}
return( 0 );
/** error exit **/
ERR_EXIT:
return( -1 );
}
/*----------------------------------------------------------------------------*\
* NAME:
* Crc32_ComputeBuf() - computes the CRC-32 value of a memory buffer
* DESCRIPTION:
* Computes or accumulates the CRC-32 value for a memory buffer.
* The 'inCrc32' gives a previously accumulated CRC-32 value to allow
* a CRC to be generated for multiple sequential buffer-fuls of data.
* The 'inCrc32' for the first buffer must be zero.
* ARGUMENTS:
* inCrc32 - accumulated CRC-32 value, must be 0 on first call
* buf - buffer to compute CRC-32 value for
* bufLen - number of bytes in buffer
* RETURNS:
* crc32 - computed CRC-32 value
* ERRORS:
* (no errors are possible)
\*----------------------------------------------------------------------------*/
unsigned long Crc32_ComputeBuf( unsigned long inCrc32, const void *buf,
size_t bufLen )
{
static const unsigned long crcTable[256] = {
0x00000000,0x77073096,0xEE0E612C,0x990951BA,0x076DC419,0x706AF48F,0xE963A535,
0x9E6495A3,0x0EDB8832,0x79DCB8A4,0xE0D5E91E,0x97D2D988,0x09B64C2B,0x7EB17CBD,
0xE7B82D07,0x90BF1D91,0x1DB71064,0x6AB020F2,0xF3B97148,0x84BE41DE,0x1ADAD47D,
0x6DDDE4EB,0xF4D4B551,0x83D385C7,0x136C9856,0x646BA8C0,0xFD62F97A,0x8A65C9EC,
0x14015C4F,0x63066CD9,0xFA0F3D63,0x8D080DF5,0x3B6E20C8,0x4C69105E,0xD56041E4,
0xA2677172,0x3C03E4D1,0x4B04D447,0xD20D85FD,0xA50AB56B,0x35B5A8FA,0x42B2986C,
0xDBBBC9D6,0xACBCF940,0x32D86CE3,0x45DF5C75,0xDCD60DCF,0xABD13D59,0x26D930AC,
0x51DE003A,0xC8D75180,0xBFD06116,0x21B4F4B5,0x56B3C423,0xCFBA9599,0xB8BDA50F,
0x2802B89E,0x5F058808,0xC60CD9B2,0xB10BE924,0x2F6F7C87,0x58684C11,0xC1611DAB,
0xB6662D3D,0x76DC4190,0x01DB7106,0x98D220BC,0xEFD5102A,0x71B18589,0x06B6B51F,
0x9FBFE4A5,0xE8B8D433,0x7807C9A2,0x0F00F934,0x9609A88E,0xE10E9818,0x7F6A0DBB,
0x086D3D2D,0x91646C97,0xE6635C01,0x6B6B51F4,0x1C6C6162,0x856530D8,0xF262004E,
0x6C0695ED,0x1B01A57B,0x8208F4C1,0xF50FC457,0x65B0D9C6,0x12B7E950,0x8BBEB8EA,
0xFCB9887C,0x62DD1DDF,0x15DA2D49,0x8CD37CF3,0xFBD44C65,0x4DB26158,0x3AB551CE,
0xA3BC0074,0xD4BB30E2,0x4ADFA541,0x3DD895D7,0xA4D1C46D,0xD3D6F4FB,0x4369E96A,
0x346ED9FC,0xAD678846,0xDA60B8D0,0x44042D73,0x33031DE5,0xAA0A4C5F,0xDD0D7CC9,
0x5005713C,0x270241AA,0xBE0B1010,0xC90C2086,0x5768B525,0x206F85B3,0xB966D409,
0xCE61E49F,0x5EDEF90E,0x29D9C998,0xB0D09822,0xC7D7A8B4,0x59B33D17,0x2EB40D81,
0xB7BD5C3B,0xC0BA6CAD,0xEDB88320,0x9ABFB3B6,0x03B6E20C,0x74B1D29A,0xEAD54739,
0x9DD277AF,0x04DB2615,0x73DC1683,0xE3630B12,0x94643B84,0x0D6D6A3E,0x7A6A5AA8,
0xE40ECF0B,0x9309FF9D,0x0A00AE27,0x7D079EB1,0xF00F9344,0x8708A3D2,0x1E01F268,
0x6906C2FE,0xF762575D,0x806567CB,0x196C3671,0x6E6B06E7,0xFED41B76,0x89D32BE0,
0x10DA7A5A,0x67DD4ACC,0xF9B9DF6F,0x8EBEEFF9,0x17B7BE43,0x60B08ED5,0xD6D6A3E8,
0xA1D1937E,0x38D8C2C4,0x4FDFF252,0xD1BB67F1,0xA6BC5767,0x3FB506DD,0x48B2364B,
0xD80D2BDA,0xAF0A1B4C,0x36034AF6,0x41047A60,0xDF60EFC3,0xA867DF55,0x316E8EEF,
0x4669BE79,0xCB61B38C,0xBC66831A,0x256FD2A0,0x5268E236,0xCC0C7795,0xBB0B4703,
0x220216B9,0x5505262F,0xC5BA3BBE,0xB2BD0B28,0x2BB45A92,0x5CB36A04,0xC2D7FFA7,
0xB5D0CF31,0x2CD99E8B,0x5BDEAE1D,0x9B64C2B0,0xEC63F226,0x756AA39C,0x026D930A,
0x9C0906A9,0xEB0E363F,0x72076785,0x05005713,0x95BF4A82,0xE2B87A14,0x7BB12BAE,
0x0CB61B38,0x92D28E9B,0xE5D5BE0D,0x7CDCEFB7,0x0BDBDF21,0x86D3D2D4,0xF1D4E242,
0x68DDB3F8,0x1FDA836E,0x81BE16CD,0xF6B9265B,0x6FB077E1,0x18B74777,0x88085AE6,
0xFF0F6A70,0x66063BCA,0x11010B5C,0x8F659EFF,0xF862AE69,0x616BFFD3,0x166CCF45,
0xA00AE278,0xD70DD2EE,0x4E048354,0x3903B3C2,0xA7672661,0xD06016F7,0x4969474D,
0x3E6E77DB,0xAED16A4A,0xD9D65ADC,0x40DF0B66,0x37D83BF0,0xA9BCAE53,0xDEBB9EC5,
0x47B2CF7F,0x30B5FFE9,0xBDBDF21C,0xCABAC28A,0x53B39330,0x24B4A3A6,0xBAD03605,
0xCDD70693,0x54DE5729,0x23D967BF,0xB3667A2E,0xC4614AB8,0x5D681B02,0x2A6F2B94,
0xB40BBE37,0xC30C8EA1,0x5A05DF1B,0x2D02EF8D };
unsigned long crc32;
unsigned char *byteBuf;
size_t i;
/** accumulate crc32 for buffer **/
crc32 = inCrc32 ^ 0xFFFFFFFF;
byteBuf = (unsigned char*) buf;
for (i=0; i < bufLen; i++) {
crc32 = (crc32 >> 8) ^ crcTable[ (crc32 ^ byteBuf[i]) & 0xFF ];
}
return( crc32 ^ 0xFFFFFFFF );
}
/*----------------------------------------------------------------------------*\
* END OF MODULE: crc32.c
\*----------------------------------------------------------------------------*/

7
appvm/crc32.h Normal file
View File

@ -0,0 +1,7 @@
#ifndef _CRC32_H
#define _CRC32_H
extern unsigned long Crc32_ComputeBuf( unsigned long inCrc32, const void *buf,
size_t bufLen );
#endif /* _CRC32_H */

7
appvm/filecopy.h
View File

@ -15,6 +15,11 @@ struct file_header {
unsigned int mtime_nsec;
};
struct result_header {
unsigned int error_code;
unsigned long crc32;
};
enum {
COPY_FILE_OK,
COPY_FILE_READ_EOF,
@ -22,5 +27,5 @@ enum {
COPY_FILE_WRITE_ERROR
};
int copy_file(int outfd, int infd, long long size);
int copy_file(int outfd, int infd, long long size, unsigned long *crc32);
char *copy_file_status_to_str(int status);

39
appvm/qfile-agent.c
View File

@ -11,6 +11,7 @@
#include <unistd.h>
#include <gui-fatal.h>
#include "filecopy.h"
#include "crc32.h"
enum {
PROGRESS_FLAG_NORMAL,
@ -18,6 +19,11 @@ enum {
PROGRESS_FLAG_DONE
};
unsigned long crc32_sum;
int write_all_with_crc(int fd, void *buf, int size) {
crc32_sum = Crc32_ComputeBuf(crc32_sum, buf, size);
return write_all(fd, buf, size);
}
char *client_flags;
@ -48,8 +54,8 @@ void notify_progress(int size, int flag)
void write_headers(struct file_header *hdr, char *filename)
{
if (!write_all(1, hdr, sizeof(*hdr))
|| !write_all(1, filename, hdr->namelen))
if (!write_all_with_crc(1, hdr, sizeof(*hdr))
|| !write_all_with_crc(1, filename, hdr->namelen))
exit(1);
}
@ -73,7 +79,7 @@ int single_file_processor(char *filename, struct stat *st)
gui_fatal("open %s", filename);
hdr.filelen = st->st_size;
write_headers(&hdr, filename);
ret = copy_file(1, fd, hdr.filelen);
ret = copy_file(1, fd, hdr.filelen, &crc32_sum);
// if COPY_FILE_WRITE_ERROR, hopefully remote will produce a message
if (ret != COPY_FILE_OK) {
if (ret != COPY_FILE_WRITE_ERROR)
@ -94,7 +100,7 @@ int single_file_processor(char *filename, struct stat *st)
gui_fatal("readlink %s", filename);
hdr.filelen = st->st_size + 1;
write_headers(&hdr, filename);
if (!write_all(1, name, st->st_size + 1))
if (!write_all_with_crc(1, name, st->st_size + 1))
exit(1);
}
return 0;
@ -149,6 +155,29 @@ char *get_item(char *data, char **current, int size)
return ret;
}
void notify_end_and_wait_for_result()
{
struct result_header hdr;
struct file_header end_hdr;
/* nofity end of transfer */
memset(&end_hdr, 0, sizeof(end_hdr));
end_hdr.namelen = 0;
end_hdr.filelen = 0;
write_all_with_crc(1, &end_hdr, sizeof(end_hdr));
/* wait for result */
if (!read_all(0, &hdr, sizeof(hdr))) {
exit(1); // hopefully remote has produced error message
}
if (hdr.error_code != 0) {
gui_fatal("Error writing files: %s", strerror(hdr.error_code));
}
if (hdr.crc32 != crc32_sum) {
gui_fatal("File transfer failed: checksum mismatch");
}
}
void parse_entry(char *data, int datasize)
{
char *current = data;
@ -157,6 +186,7 @@ void parse_entry(char *data, int datasize)
client_flags = get_item(data, &current, datasize);
notify_progress(0, PROGRESS_FLAG_INIT);
send_vmname(vmname);
crc32_sum = 0;
while ((entry = get_item(data, &current, datasize))) {
do {
sep = rindex(entry, '/');
@ -171,6 +201,7 @@ void parse_entry(char *data, int datasize)
gui_fatal("chdir to %s", entry);
do_fs_walk(sep + 1);
}
notify_end_and_wait_for_result();
notify_progress(0, PROGRESS_FLAG_DONE);
}

38
appvm/unpack.c
View File

@ -7,12 +7,22 @@
#include <unistd.h>
#include <stdio.h>
#include "filecopy.h"
#include "crc32.h"
char untrusted_namebuf[MAX_PATH_LENGTH];
void notify_progress(int p1, int p2)
{
}
unsigned long crc32_sum = 0;
int read_all_with_crc(int fd, void *buf, int size) {
int ret;
ret = read_all(fd, buf, size);
if (ret)
crc32_sum = Crc32_ComputeBuf(crc32_sum, buf, size);
return ret;
}
int global_status_fd;
void do_exit(int code)
{
@ -45,7 +55,7 @@ void process_one_file_reg(struct file_header *untrusted_hdr,
int fdout = open(untrusted_name, O_WRONLY | O_CREAT | O_EXCL | O_NOFOLLOW, 0700); /* safe because of chroot */
if (fdout < 0)
do_exit(errno);
ret = copy_file(fdout, 0, untrusted_hdr->filelen);
ret = copy_file(fdout, 0, untrusted_hdr->filelen, &crc32_sum);
if (ret != COPY_FILE_OK) {
if (ret == COPY_FILE_READ_EOF
|| ret == COPY_FILE_READ_ERROR)
@ -78,7 +88,7 @@ void process_one_file_link(struct file_header *untrusted_hdr,
if (untrusted_hdr->filelen > MAX_PATH_LENGTH - 1)
do_exit(ENAMETOOLONG);
filelen = untrusted_hdr->filelen; /* sanitized above */
if (!read_all(0, untrusted_content, filelen))
if (!read_all_with_crc(0, untrusted_content, filelen))
do_exit(LEGAL_EOF); // hopefully remote has produced error message
untrusted_content[filelen] = 0;
if (symlink(untrusted_content, untrusted_name)) /* safe because of chroot */
@ -92,7 +102,7 @@ void process_one_file(struct file_header *untrusted_hdr)
if (untrusted_hdr->namelen > MAX_PATH_LENGTH - 1)
do_exit(ENAMETOOLONG);
namelen = untrusted_hdr->namelen; /* sanitized above */
if (!read_all(0, untrusted_namebuf, namelen))
if (!read_all_with_crc(0, untrusted_namebuf, namelen))
do_exit(LEGAL_EOF); // hopefully remote has produced error message
untrusted_namebuf[namelen] = 0;
if (S_ISREG(untrusted_hdr->mode))
@ -105,12 +115,32 @@ void process_one_file(struct file_header *untrusted_hdr)
do_exit(EINVAL);
}
void send_status_and_crc() {
struct result_header hdr;
int saved_errno;
saved_errno = errno;
hdr.error_code = errno;
hdr.crc32 = crc32_sum;
write_all(1, &hdr, sizeof(hdr));
errno = saved_errno;
}
void do_unpack(int fd)
{
global_status_fd = fd;
struct file_header untrusted_hdr;
while (read_all(0, &untrusted_hdr, sizeof untrusted_hdr))
/* initialize checksum */
crc32_sum = 0;
while (read_all_with_crc(0, &untrusted_hdr, sizeof untrusted_hdr)) {
/* check for end of transfer marker */
if (untrusted_hdr.namelen == 0) {
errno = 0;
break;
}
process_one_file(&untrusted_hdr);
}
send_status_and_crc();
if (errno)
do_exit(errno);
else