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| author | Denys Vlasenko <vda.linux@googlemail.com> | 2013-08-20 02:50:49 +0200 |
|---|---|---|
| committer | Denys Vlasenko <vda.linux@googlemail.com> | 2013-08-20 02:50:49 +0200 |
| commit | 5b9910f0a4a1b7976c46e6f849aaa263180e5521 (patch) | |
| tree | 4e5f1a63caa21286a01d5f6c2a3e585bcdf61ec9 /coreutils/dd.c | |
| parent | e66a56de23fd08907f324d79e61ed2930ea5c350 (diff) | |
| download | busybox-w32-5b9910f0a4a1b7976c46e6f849aaa263180e5521.tar.gz busybox-w32-5b9910f0a4a1b7976c46e6f849aaa263180e5521.tar.bz2 busybox-w32-5b9910f0a4a1b7976c46e6f849aaa263180e5521.zip | |
dd: fail if swab is attempted on odd-sized block
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'coreutils/dd.c')
| -rw-r--r-- | coreutils/dd.c | 31 |
1 files changed, 21 insertions, 10 deletions
diff --git a/coreutils/dd.c b/coreutils/dd.c index d6aa5efb1..e22938859 100644 --- a/coreutils/dd.c +++ b/coreutils/dd.c | |||
| @@ -151,13 +151,13 @@ int dd_main(int argc UNUSED_PARAM, char **argv) | |||
| 151 | enum { | 151 | enum { |
| 152 | /* Must be in the same order as OP_conv_XXX! */ | 152 | /* Must be in the same order as OP_conv_XXX! */ |
| 153 | /* (see "flags |= (1 << what)" below) */ | 153 | /* (see "flags |= (1 << what)" below) */ |
| 154 | FLAG_NOTRUNC = 1 << 0, | 154 | FLAG_NOTRUNC = (1 << 0) * ENABLE_FEATURE_DD_IBS_OBS, |
| 155 | FLAG_SYNC = 1 << 1, | 155 | FLAG_SYNC = (1 << 1) * ENABLE_FEATURE_DD_IBS_OBS, |
| 156 | FLAG_NOERROR = 1 << 2, | 156 | FLAG_NOERROR = (1 << 2) * ENABLE_FEATURE_DD_IBS_OBS, |
| 157 | FLAG_FSYNC = 1 << 3, | 157 | FLAG_FSYNC = (1 << 3) * ENABLE_FEATURE_DD_IBS_OBS, |
| 158 | FLAG_SWAB = 1 << 4, | 158 | FLAG_SWAB = (1 << 4) * ENABLE_FEATURE_DD_IBS_OBS, |
| 159 | /* end of conv flags */ | 159 | /* end of conv flags */ |
| 160 | FLAG_TWOBUFS = 1 << 5, | 160 | FLAG_TWOBUFS = (1 << 5) * ENABLE_FEATURE_DD_IBS_OBS, |
| 161 | FLAG_COUNT = 1 << 6, | 161 | FLAG_COUNT = 1 << 6, |
| 162 | }; | 162 | }; |
| 163 | static const char keywords[] ALIGN1 = | 163 | static const char keywords[] ALIGN1 = |
| @@ -202,7 +202,7 @@ int dd_main(int argc UNUSED_PARAM, char **argv) | |||
| 202 | //swab swap every pair of input bytes: will abort on non-even reads | 202 | //swab swap every pair of input bytes: will abort on non-even reads |
| 203 | #endif | 203 | #endif |
| 204 | }; | 204 | }; |
| 205 | int exitcode = EXIT_FAILURE; | 205 | smallint exitcode = EXIT_FAILURE; |
| 206 | size_t ibs = 512, obs = 512; | 206 | size_t ibs = 512, obs = 512; |
| 207 | int i; | 207 | int i; |
| 208 | char *ibuf, *obuf; | 208 | char *ibuf, *obuf; |
| @@ -210,12 +210,14 @@ int dd_main(int argc UNUSED_PARAM, char **argv) | |||
| 210 | struct { | 210 | struct { |
| 211 | int flags; | 211 | int flags; |
| 212 | size_t oc; | 212 | size_t oc; |
| 213 | ssize_t prev_read_size; /* for detecting swab failure */ | ||
| 213 | off_t count; | 214 | off_t count; |
| 214 | off_t seek, skip; | 215 | off_t seek, skip; |
| 215 | const char *infile, *outfile; | 216 | const char *infile, *outfile; |
| 216 | } Z; | 217 | } Z; |
| 217 | #define flags (Z.flags ) | 218 | #define flags (Z.flags ) |
| 218 | #define oc (Z.oc ) | 219 | #define oc (Z.oc ) |
| 220 | #define prev_read_size (Z.prev_read_size) | ||
| 219 | #define count (Z.count ) | 221 | #define count (Z.count ) |
| 220 | #define seek (Z.seek ) | 222 | #define seek (Z.seek ) |
| 221 | #define skip (Z.skip ) | 223 | #define skip (Z.skip ) |
| @@ -381,14 +383,23 @@ int dd_main(int argc UNUSED_PARAM, char **argv) | |||
| 381 | n = 0; | 383 | n = 0; |
| 382 | } | 384 | } |
| 383 | if (flags & FLAG_SWAB) { | 385 | if (flags & FLAG_SWAB) { |
| 384 | /* If n is odd, last byte is not swapped: | 386 | uint16_t *p16, *end; |
| 387 | |||
| 388 | /* Our code allows only last read to be odd-sized */ | ||
| 389 | if (prev_read_size & 1) | ||
| 390 | bb_error_msg_and_die("can't swab %lu byte buffer", | ||
| 391 | (unsigned long)prev_read_size); | ||
| 392 | prev_read_size = n; | ||
| 393 | |||
| 394 | /* | ||
| 395 | * If n is odd, last byte is not swapped: | ||
| 385 | * echo -n "qwe" | dd conv=swab | 396 | * echo -n "qwe" | dd conv=swab |
| 386 | * prints "wqe". | 397 | * prints "wqe". |
| 387 | * The code does not handle correctly odd-sized reads | 398 | * The code does not handle correctly odd-sized reads |
| 388 | * in the *middle* of the input. FIXME. | 399 | * in the *middle* of the input. FIXME. |
| 389 | */ | 400 | */ |
| 390 | uint16_t *p16 = (void*) ibuf; | 401 | p16 = (void*) ibuf; |
| 391 | uint16_t *end = (void*) (ibuf + (n & ~(ssize_t)1)); | 402 | end = (void*) (ibuf + (n & ~(ssize_t)1)); |
| 392 | while (p16 < end) { | 403 | while (p16 < end) { |
| 393 | *p16 = bswap_16(*p16); | 404 | *p16 = bswap_16(*p16); |
| 394 | p16++; | 405 | p16++; |