[hackers] [ubase] fix several problems in dd || izabera

From: <git_AT_suckless.org>
Date: Mon, 4 Jan 2016 19:07:55 +0100 (CET)

commit 3af0bbd564f42d9b70e0f854a6e0ab8add1e7aee
Author: izabera <izaberina_AT_gmail.com>
AuthorDate: Fri Jan 1 11:05:06 2016 +0100
Commit: sin <sin_AT_2f30.org>
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
_AT_@ -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;
 };
 
_AT_@ -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;
 
_AT_@ -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;
                 }
         }
 
_AT_@ -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;
         }
_AT_@ -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);
 
_AT_@ -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;
_AT_@ -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;
                 }
_AT_@ -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)
_AT_@ -282,9 +277,6 @@ main(int argc, char *argv[])
                         usage();
         }
 
- if (!config.in || !config.out)
- usage();
-
         signal(SIGPIPE, SIG_IGN);
         signal(SIGINT, sig_int);
 
_AT_@ -294,5 +286,5 @@ main(int argc, char *argv[])
 
         if (config.nosync == 0)
                 sync();
- return config.saved_errno;
+ return errno;
 }
Received on Mon Jan 04 2016 - 19:07:55 CET