Cleanup pass on dd: Implement 1x2x3 posix nonsense, detect overflow,
TT.buff is shared between input and output so shouldn't live in both.
diff --git a/toys/pending/dd.c b/toys/pending/dd.c
index 9a4d6df..77ebd88 100644
--- a/toys/pending/dd.c
+++ b/toys/pending/dd.c
@@ -17,7 +17,7 @@
keyword=value modifiers (and their default values):
if=FILE Read FILE (stdin) of=FILE Write to FILE (stdout)
- bs=N Block size in bytes (512) count=N Stop after copying N blocks
+ bs=N Block size in bytes (512) count=N Stop after copying N blocks (all)
ibs=N Input block size (bs=) obs=N Output block size (bs=)
skip=N Skip N input blocks (0) seek=N Skip N output blocks (0)
@@ -41,10 +41,10 @@
GLOBALS(
int show_xfer, show_records;
unsigned long long bytes, in_full, in_part, out_full, out_part, start;
+ char *buff;
struct {
- char *name;
+ char *name, *bp;
int fd;
- unsigned char *buff, *bp;
long sz, count;
unsigned long long offset;
} in, out;
@@ -86,9 +86,9 @@
static void write_out(int all)
{
- TT.out.bp = TT.out.buff;
+ TT.out.bp = TT.buff;
while (TT.out.count) {
- ssize_t nw = writeall(TT.out.fd, TT.out.bp, ((all)? TT.out.count : TT.out.sz));
+ ssize_t nw = writeall(TT.out.fd, TT.out.bp, all ? TT.out.count : TT.out.sz);
all = 0; //further writes will be on obs
if (nw <= 0) perror_exit("%s: write error", TT.out.name);
@@ -99,7 +99,8 @@
TT.bytes += nw;
if (TT.out.count < TT.out.sz) break;
}
- if (TT.out.count) memmove(TT.out.buff, TT.out.bp, TT.out.count); //move remainder to front
+ // move remainder to front (if any)
+ if (TT.out.count) memmove(TT.buff, TT.out.bp, TT.out.count);
}
static void parse_flags(char *what, char *arg,
@@ -114,6 +115,40 @@
free(pre);
}
+// Multiply detecting overflow.
+static unsigned long long overmul(unsigned long long x, unsigned long long y)
+{
+ unsigned long long ll = x*y;
+
+ if (x && y && (ll<x || ll<y)) error_exit("overflow");
+
+ return ll;
+}
+
+// Handle funky posix 1x2x3 syntax.
+static unsigned long long argxarg(char *arg, int cap)
+{
+ long long ll = 1;
+ char x, *s, *new;
+
+ arg = xstrdup(arg);
+ for (new = s = arg;; new = s+1) {
+ // atolx() handlex 0x hex prefixes, so skip past those looking for separator
+ if ((s = strchr(new+2*!strncmp(new, "0x", 2), 'x'))) {
+ if (s==new) break;
+ x = *s;
+ *s = 0;
+ }
+ ll = overmul(ll, atolx(new));
+ if (s) *s = x;
+ else break;
+ }
+ if (s || ll<cap || ll>(cap ? LONG_MAX : LLONG_MAX)) error_exit("bad %s", arg);
+ free(arg);
+
+ return ll;
+}
+
void dd_main()
{
char **args, *arg;
@@ -124,16 +159,14 @@
TT.in.sz = TT.out.sz = 512; //default io block size
for (args = toys.optargs; (arg = *args); args++) {
- if (strstart(&arg, "bs=")) bs = atolx_range(arg, 1, LONG_MAX);
- else if (strstart(&arg, "ibs=")) TT.in.sz = atolx_range(arg, 1, LONG_MAX);
- else if (strstart(&arg, "obs=")) TT.out.sz = atolx_range(arg, 1, LONG_MAX);
- else if (strstart(&arg, "count=")) count = atolx_range(arg, 0, LLONG_MAX);
+ if (strstart(&arg, "bs=")) bs = argxarg(arg, 1);
+ else if (strstart(&arg, "ibs=")) TT.in.sz = argxarg(arg, 1);
+ else if (strstart(&arg, "obs=")) TT.out.sz = argxarg(arg, 1);
+ else if (strstart(&arg, "count=")) count = argxarg(arg, 0);
else if (strstart(&arg, "if=")) TT.in.name = arg;
else if (strstart(&arg, "of=")) TT.out.name = arg;
- else if (strstart(&arg, "seek="))
- TT.out.offset = atolx_range(arg, 0, LLONG_MAX);
- else if (strstart(&arg, "skip="))
- TT.in.offset = atolx_range(arg, 0, LLONG_MAX);
+ else if (strstart(&arg, "seek=")) TT.out.offset = argxarg(arg, 0);
+ else if (strstart(&arg, "skip=")) TT.in.offset = argxarg(arg, 0);
else if (strstart(&arg, "status=")) {
if (!strcmp(arg, "noxfer")) TT.show_xfer = 0;
else if (!strcmp(arg, "none")) TT.show_xfer = TT.show_records = 0;
@@ -154,8 +187,7 @@
// For bs=, in/out is done as it is. so only in.sz is enough.
// With Single buffer there will be overflow in a read following partial read.
- TT.in.buff = TT.out.buff = xmalloc(TT.in.sz + (bs ? 0 : TT.out.sz));
- TT.in.bp = TT.out.bp = TT.in.buff;
+ TT.in.bp = TT.out.bp = TT.buff = xmalloc(TT.in.sz+TT.out.sz*!bs);
if (!TT.in.name) TT.in.name = "stdin";
else TT.in.fd = xopenro(TT.in.name);
@@ -170,13 +202,12 @@
// Implement skip=
if (TT.in.offset) {
- off_t off = TT.in.offset;
+ unsigned long long off = TT.in.offset;
if (!(TT.iflag & _DD_iflag_skip_bytes)) off *= TT.in.sz;
if (lseek(TT.in.fd, off, SEEK_CUR) < 0) {
while (off > 0) {
- int chunk = off < TT.in.sz ? off : TT.in.sz;
- ssize_t n = read(TT.in.fd, TT.in.bp, chunk);
+ ssize_t n = read(TT.in.fd, TT.in.bp, minof(off, TT.in.sz));
if (n < 0) {
perror_msg("%s", TT.in.name);
@@ -203,19 +234,19 @@
&& ftruncate(TT.out.fd, bs)) perror_exit("truncate");
}
- if (!(TT.iflag & _DD_iflag_count_bytes) && count*TT.in.sz>count)
- count *= TT.in.sz;
+ if (count!=ULLONG_MAX && !(TT.iflag & _DD_iflag_count_bytes))
+ count = overmul(count, TT.in.sz);
while (count) {
- int chunk = minof(count, TT.in.sz);
ssize_t n;
- TT.in.bp = TT.in.buff + TT.in.count;
+ TT.in.bp = TT.buff + TT.in.count;
if (TT.conv & _DD_conv_sync) memset(TT.in.bp, 0, TT.in.sz);
errno = 0;
- if (!(n = read(TT.in.fd, TT.in.bp, chunk))) break;
- if (n < 0) {
+ if (1>(n = read(TT.in.fd, TT.in.bp, minof(count, TT.in.sz)))) {
if (errno == EINTR) continue;
+ if (!n) break;
+
//read error case.
perror_msg("%s: read error", TT.in.name);
if (!(TT.conv & _DD_conv_noerror)) exit(1);
@@ -248,10 +279,12 @@
}
}
if (TT.out.count) write_out(1); //write any remaining input blocks
- if ((TT.conv & _DD_conv_fsync) && fsync(TT.out.fd)<0)
+ if ((TT.conv & _DD_conv_fsync) && fsync(TT.out.fd))
perror_exit("%s: fsync", TT.out.name);
- close(TT.in.fd);
- close(TT.out.fd);
- if (TT.in.buff) free(TT.in.buff);
+ if (CFG_TOYBOX_FREE) {
+ close(TT.in.fd);
+ close(TT.out.fd);
+ if (TT.buff) free(TT.buff);
+ }
}
