diff options
Diffstat (limited to 'bin/dd/position.c')
| -rw-r--r-- | bin/dd/position.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/bin/dd/position.c b/bin/dd/position.c index 5299c5b..74b612c 100644 --- a/bin/dd/position.c +++ b/bin/dd/position.c @@ -47,6 +47,7 @@ static const char rcsid[] = #include <sys/mtio.h> #include <err.h> +#include <errno.h> #include <unistd.h> #include "dd.h" @@ -67,7 +68,8 @@ pos_in() /* If not a character, pipe or tape device, try to seek on it. */ if (!(in.flags & (ISCHR|ISPIPE|ISTAPE)) || in.flags & ISDISK) { - if (lseek(in.fd, in.offset * in.dbsz, SEEK_CUR) == -1) + errno = 0; + if (lseek(in.fd, in.offset * in.dbsz, SEEK_CUR) == -1 && errno) err(1, "%s", in.name); return; } @@ -77,6 +79,8 @@ pos_in() * being skipped. No differentiation for reading complete and partial * blocks for other devices. */ + if (in.offset < 0) + errx(1, "skip must be positive"); for (bcnt = in.dbsz, cnt = in.offset, warned = 0; cnt;) { if ((nr = read(in.fd, in.db, bcnt)) > 0) { if (in.flags & ISPIPE) { @@ -123,7 +127,9 @@ pos_out() /* If not a character, pipe or tape device, try to seek on it. */ if (!(out.flags & (ISCHR|ISPIPE|ISTAPE)) || out.flags & ISDISK) { - if (lseek(out.fd, out.offset * out.dbsz, SEEK_SET) == -1) + errno = 0; + if (lseek(out.fd, out.offset * out.dbsz, SEEK_SET) == -1 && + errno) err(1, "%s", out.name); return; } @@ -139,6 +145,8 @@ pos_out() } /* Read it. */ + if (out.offset < 0) + errx(1, "seek must be positive"); for (cnt = 0; cnt < out.offset; ++cnt) { if ((n = read(out.fd, out.db, out.dbsz)) > 0) continue; |
