diff options
| -rw-r--r-- | coreutils/dd.c | 85 |
1 files changed, 53 insertions, 32 deletions
diff --git a/coreutils/dd.c b/coreutils/dd.c index 22ad192..75cf373 100644 --- a/coreutils/dd.c +++ b/coreutils/dd.c @@ -32,6 +32,9 @@ struct globals { off_t out_full, out_part, in_full, in_part; }; #define G (*(struct globals*)&bb_common_bufsiz1) +/* We have to zero it out because of NOEXEC */ +#define INIT_G() memset(&G, 0, sizeof(G)) + static void dd_output_status(int ATTRIBUTE_UNUSED cur_signal) { @@ -73,10 +76,11 @@ int dd_main(int argc, char **argv); int dd_main(int argc, char **argv) { enum { - SYNC_FLAG = 1 << 0, - NOERROR = 1 << 1, - TRUNC_FLAG = 1 << 2, - TWOBUFS_FLAG = 1 << 3, + FLAG_SYNC = 1 << 0, + FLAG_NOERROR = 1 << 1, + FLAG_NOTRUNC = 1 << 2, + FLAG_TWOBUFS = 1 << 3, + FLAG_COUNT = 1 << 4, }; static const char keywords[] = "bs=\0""count=\0""seek=\0""skip=\0""if=\0""of=\0" @@ -100,25 +104,41 @@ int dd_main(int argc, char **argv) OP_conv_noerror, #endif }; - int flags = TRUNC_FLAG; - size_t oc = 0, ibs = 512, obs = 512; + size_t ibs = 512, obs = 512; ssize_t n, w; - off_t seek = 0, skip = 0, count = OFF_T_MAX; - int ifd, ofd; - const char *infile = NULL, *outfile = NULL; char *ibuf, *obuf; + /* And these are all zeroed at once! */ + struct { + int flags; + int ifd, ofd; + size_t oc; + off_t count; + off_t seek, skip; + const char *infile, *outfile; +#if ENABLE_FEATURE_DD_SIGNAL_HANDLING + struct sigaction sigact; +#endif + } Z; +#define flags (Z.flags ) +#define ifd (Z.ifd ) +#define ofd (Z.ofd ) +#define oc (Z.oc ) +#define count (Z.count ) +#define seek (Z.seek ) +#define skip (Z.skip ) +#define infile (Z.infile ) +#define outfile (Z.outfile) +#define sigact (Z.sigact ) - memset(&G, 0, sizeof(G)); /* because of NOEXEC */ - - if (ENABLE_FEATURE_DD_SIGNAL_HANDLING) { - struct sigaction sa; + memset(&Z, 0, sizeof(Z)); + INIT_G(); - memset(&sa, 0, sizeof(sa)); - sa.sa_handler = dd_output_status; - sa.sa_flags = SA_RESTART; - sigemptyset(&sa.sa_mask); - sigaction(SIGUSR1, &sa, 0); - } +#if ENABLE_FEATURE_DD_SIGNAL_HANDLING + sigact.sa_handler = dd_output_status; + sigact.sa_flags = SA_RESTART; + sigemptyset(&sigact.sa_mask); + sigaction(SIGUSR1, &sigact, NULL); +#endif for (n = 1; n < argc; n++) { smalluint key_len; @@ -162,11 +182,11 @@ int dd_main(int argc, char **argv) if (what < OP_conv_notrunc) bb_error_msg_and_die(bb_msg_invalid_arg, arg, "conv"); if (what == OP_conv_notrunc) - flags &= ~TRUNC_FLAG; + flags |= FLAG_NOTRUNC; if (what == OP_conv_sync) - flags |= SYNC_FLAG; + flags |= FLAG_SYNC; if (what == OP_conv_noerror) - flags |= NOERROR; + flags |= FLAG_NOERROR; if (!key) /* no ',' left, so this was the last specifier */ break; arg = key + 1; /* skip this keyword and ',' */ @@ -180,6 +200,7 @@ int dd_main(int argc, char **argv) } /* These can be large: */ if (what == OP_count) { + flags |= FLAG_COUNT; count = XATOU_SFX(arg, dd_suffixes); continue; } @@ -201,24 +222,24 @@ int dd_main(int argc, char **argv) //XXX:FIXME for huge ibs or obs, malloc'ing them isn't the brightest idea ever ibuf = obuf = xmalloc(ibs); if (ibs != obs) { - flags |= TWOBUFS_FLAG; + flags |= FLAG_TWOBUFS; obuf = xmalloc(obs); } if (infile != NULL) ifd = xopen(infile, O_RDONLY); else { - ifd = STDIN_FILENO; + /* ifd = STDIN_FILENO; - it's zero and it's already there */ infile = bb_msg_standard_input; } if (outfile != NULL) { int oflag = O_WRONLY | O_CREAT; - if (!seek && (flags & TRUNC_FLAG)) + if (!seek && !(flags & FLAG_NOTRUNC)) oflag |= O_TRUNC; ofd = xopen(outfile, oflag); - if (seek && (flags & TRUNC_FLAG)) { + if (seek && !(flags & FLAG_NOTRUNC)) { if (ftruncate(ofd, seek * obs) < 0) { struct stat st; @@ -247,14 +268,14 @@ int dd_main(int argc, char **argv) goto die_outfile; } - while (G.in_full + G.in_part != count) { - if (flags & NOERROR) /* Pre-zero the buffer when for NOERROR */ - memset(ibuf, '\0', ibs); + while ((flags & FLAG_COUNT) && (G.in_full + G.in_part != count)) { + if (flags & FLAG_NOERROR) /* Pre-zero the buffer if conv=noerror */ + memset(ibuf, 0, ibs); n = safe_read(ifd, ibuf, ibs); if (n == 0) break; if (n < 0) { - if (flags & NOERROR) { + if (flags & FLAG_NOERROR) { n = ibs; bb_perror_msg("%s", infile); } else @@ -264,12 +285,12 @@ int dd_main(int argc, char **argv) G.in_full++; else { G.in_part++; - if (flags & SYNC_FLAG) { + if (flags & FLAG_SYNC) { memset(ibuf + n, '\0', ibs - n); n = ibs; } } - if (flags & TWOBUFS_FLAG) { + if (flags & FLAG_TWOBUFS) { char *tmp = ibuf; while (n) { size_t d = obs - oc; |