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| author | Denys Vlasenko | 2013-08-20 02:50:49 +0200 |
|---|---|---|
| committer | Denys Vlasenko | 2013-08-20 02:50:49 +0200 |
| commit | 5b9910f0a4a1b7976c46e6f849aaa263180e5521 (patch) | |
| tree | 4e5f1a63caa21286a01d5f6c2a3e585bcdf61ec9 | |
| parent | e66a56de23fd08907f324d79e61ed2930ea5c350 (diff) | |
| download | busybox-5b9910f0a4a1b7976c46e6f849aaa263180e5521.zip busybox-5b9910f0a4a1b7976c46e6f849aaa263180e5521.tar.gz | |
dd: fail if swab is attempted on odd-sized block
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
| -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 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++; |