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authorDenys Vlasenko <vda.linux@googlemail.com>2013-08-20 00:50:49 (GMT)
committer Denys Vlasenko <vda.linux@googlemail.com>2013-08-20 00:50:49 (GMT)
commit5b9910f0a4a1b7976c46e6f849aaa263180e5521 (patch)
tree4e5f1a63caa21286a01d5f6c2a3e585bcdf61ec9
parente66a56de23fd08907f324d79e61ed2930ea5c350 (diff)
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dd: fail if swab is attempted on odd-sized block
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--coreutils/dd.c31
1 files changed, 21 insertions, 10 deletions
diff --git a/coreutils/dd.c b/coreutils/dd.c
index d6aa5ef..e229388 100644
--- a/coreutils/dd.c
+++ b/coreutils/dd.c
@@ -151,13 +151,13 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
enum {
/* Must be in the same order as OP_conv_XXX! */
/* (see "flags |= (1 << what)" below) */
- FLAG_NOTRUNC = 1 << 0,
- FLAG_SYNC = 1 << 1,
- FLAG_NOERROR = 1 << 2,
- FLAG_FSYNC = 1 << 3,
- FLAG_SWAB = 1 << 4,
+ FLAG_NOTRUNC = (1 << 0) * ENABLE_FEATURE_DD_IBS_OBS,
+ FLAG_SYNC = (1 << 1) * ENABLE_FEATURE_DD_IBS_OBS,
+ FLAG_NOERROR = (1 << 2) * ENABLE_FEATURE_DD_IBS_OBS,
+ FLAG_FSYNC = (1 << 3) * ENABLE_FEATURE_DD_IBS_OBS,
+ FLAG_SWAB = (1 << 4) * ENABLE_FEATURE_DD_IBS_OBS,
/* end of conv flags */
- FLAG_TWOBUFS = 1 << 5,
+ FLAG_TWOBUFS = (1 << 5) * ENABLE_FEATURE_DD_IBS_OBS,
FLAG_COUNT = 1 << 6,
};
static const char keywords[] ALIGN1 =
@@ -202,7 +202,7 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
//swab swap every pair of input bytes: will abort on non-even reads
#endif
};
- int exitcode = EXIT_FAILURE;
+ smallint exitcode = EXIT_FAILURE;
size_t ibs = 512, obs = 512;
int i;
char *ibuf, *obuf;
@@ -210,12 +210,14 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
struct {
int flags;
size_t oc;
+ ssize_t prev_read_size; /* for detecting swab failure */
off_t count;
off_t seek, skip;
const char *infile, *outfile;
} Z;
#define flags (Z.flags )
#define oc (Z.oc )
+#define prev_read_size (Z.prev_read_size)
#define count (Z.count )
#define seek (Z.seek )
#define skip (Z.skip )
@@ -381,14 +383,23 @@ int dd_main(int argc UNUSED_PARAM, char **argv)
n = 0;
}
if (flags & FLAG_SWAB) {
- /* If n is odd, last byte is not swapped:
+ uint16_t *p16, *end;
+
+ /* Our code allows only last read to be odd-sized */
+ if (prev_read_size & 1)
+ bb_error_msg_and_die("can't swab %lu byte buffer",
+ (unsigned long)prev_read_size);
+ prev_read_size = n;
+
+ /*
+ * If n is odd, last byte is not swapped:
* echo -n "qwe" | dd conv=swab
* prints "wqe".
* The code does not handle correctly odd-sized reads
* in the *middle* of the input. FIXME.
*/
- uint16_t *p16 = (void*) ibuf;
- uint16_t *end = (void*) (ibuf + (n & ~(ssize_t)1));
+ p16 = (void*) ibuf;
+ end = (void*) (ibuf + (n & ~(ssize_t)1));
while (p16 < end) {
*p16 = bswap_16(*p16);
p16++;