commit 3af0bbd564f42d9b70e0f854a6e0ab8add1e7aee
Author: izabera <[email protected]>
AuthorDate: Fri Jan 1 11:05:06 2016 +0100
Commit: sin <[email protected]>
CommitDate: Mon Jan 4 18:07:44 2016 +0000
fix several problems in dd
diff --git a/dd.c b/dd.c
index 8f802ac..977f0f0 100644
--- a/dd.c
+++ b/dd.c
@@ -33,7 +33,6 @@ struct dd_config {
off_t fsize;
blksize_t bs;
char quiet, nosync, direct;
- int saved_errno;
time_t t_start, t_end;
};
@@ -52,20 +51,17 @@ prepare_copy(struct dd_config *ddc, int *ifd, int *ofd)
flo |= O_DIRECT;
}
- if (stat(ddc->in, &st) < 0) {
- ddc->saved_errno = errno;
- return -1;
- }
-
euid = geteuid();
if (!euid || st.st_uid == euid)
fli |= O_NOATIME;
- if ((*ifd = open(ddc->in, fli)) < 0) {
- ddc->saved_errno = errno;
+ if (!ddc->in) *ifd = 0;
+ else if ((*ifd = open(ddc->in, fli)) < 0)
+ return -1;
+
+ if (fstat(*ifd, &st) < 0)
return -1;
- }
ddc->fsize = st.st_size;
@@ -90,14 +86,11 @@ prepare_copy(struct dd_config *ddc, int *ifd, int *ofd)
if (!S_ISREG(st.st_mode)) {
if (S_ISBLK(st.st_mode)) {
if (ioctl(*ifd, BLKGETSIZE64, &ddc->fsize) < 0) {
- ddc->saved_errno = errno;
close(*ifd);
return -1;
}
} else {
ddc->fsize = (off_t)-1;
- if (ddc->count)
- ddc->fsize = ddc->count*ddc->bs;
}
}
@@ -107,7 +100,7 @@ prepare_copy(struct dd_config *ddc, int *ifd, int *ofd)
/* skip more bytes than are inside source file? */
if (ddc->fsize != (off_t)-1 && ddc->skip >= (uint64_t)ddc->fsize) {
- ddc->saved_errno = EINVAL;
+ errno = EINVAL;
close(*ifd);
return -1;
}
@@ -115,14 +108,23 @@ prepare_copy(struct dd_config *ddc, int *ifd, int *ofd)
if (!ddc->seek)
flo |= O_CREAT|O_TRUNC;
- if ((*ofd = open(ddc->out, flo, st.st_mode)) < 0) {
- ddc->saved_errno = errno;
+ if (!ddc->out) *ofd = 1;
+ else if ((*ofd = open(ddc->out, flo, st.st_mode)) < 0) {
close(*ifd);
return -1;
}
- lseek(*ifd, ddc->skip, SEEK_SET);
- lseek(*ofd, ddc->seek, SEEK_SET);
+ if (lseek(*ifd, ddc->skip, SEEK_CUR) < 0) {
+ char buffer[ddc->bs];
+ for (uint64_t i = 0; i < ddc->skip; i += ddc->bs) {
+ if (read(*ifd, &buffer, ddc->bs) < 0) {
+ errno = EINVAL;
+ close(*ifd);
+ return -1;
+ }
+ }
+ }
+ lseek(*ofd, ddc->seek, SEEK_CUR);
posix_fadvise(*ifd, ddc->skip, 0, POSIX_FADV_SEQUENTIAL);
posix_fadvise(*ofd, 0, 0, POSIX_FADV_DONTNEED);
@@ -147,7 +149,6 @@ copy_splice(struct dd_config *ddc)
if (prepare_copy(ddc, &ifd, &ofd) < 0)
return -1;
if (pipe(p) < 0) {
- ddc->saved_errno = errno;
close(ifd); close(ofd);
close(p[0]); close(p[1]);
return -1;
@@ -165,24 +166,18 @@ copy_splice(struct dd_config *ddc)
FD_SET(ifd, &rfd);
FD_SET(ofd, &wfd);
r = select(ifd > ofd ? ifd + 1 : ofd + 1, &rfd, &wfd, NULL,
NULL);
- if (r < 0) {
- ddc->saved_errno = errno;
+ if (r < 0)
break;
- }
if (FD_ISSET(ifd, &rfd) == 1 && FD_ISSET(ofd, &wfd) == 1) {
if (n > ddc->count - ddc->b_out)
n = ddc->count - ddc->b_out;
r = splice(ifd, NULL, p[1], NULL, n, SPLICE_F_MORE);
- if (r <= 0) {
- ddc->saved_errno = errno;
+ if (r <= 0)
break;
- }
++ddc->rec_in;
r = splice(p[0], NULL, ofd, NULL, r, SPLICE_F_MORE);
- if (r <= 0) {
- ddc->saved_errno = errno;
+ if (r <= 0)
break;
- }
ddc->b_out += r;
++ddc->rec_out;
}
@@ -252,16 +247,16 @@ main(int argc, char *argv[])
argv0 = argv[0];
memset(&config, 0, sizeof(config));
config.bs = 1<<16;
- config.in = "/dev/stdin";
- config.out = "/dev/stdout";
+ config.in = NULL;
+ config.out = NULL;
/* emulate 'dd' argument parsing */
for (i = 1; i < argc; ++i) {
memset(buf, 0, sizeof(buf));
- if (sscanf(argv[i], "if=%1023s", buf) == 1)
- config.in = strdup(buf);
- else if (sscanf(argv[i], "of=%1023s", buf) == 1)
- config.out = strdup(buf);
+ if (strncmp(argv[i], "if=", 3) == 0)
+ config.in = argv[i]+3;
+ else if (strncmp(argv[i], "of=", 3) == 0)
+ config.out = argv[i]+3;
else if (sscanf(argv[i], "skip=%1023s", buf) == 1)
config.skip = estrtoul(buf, 0);
else if (sscanf(argv[i], "seek=%1023s", buf) == 1)
@@ -282,9 +277,6 @@ main(int argc, char *argv[])
usage();
}
- if (!config.in || !config.out)
- usage();
-
signal(SIGPIPE, SIG_IGN);
signal(SIGINT, sig_int);
@@ -294,5 +286,5 @@ main(int argc, char *argv[])
if (config.nosync == 0)
sync();
- return config.saved_errno;
+ return errno;
}
