ubase

suckless linux base utils
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commit a09f122f60f1671e27297569b3e3a4eff2c2422c
parent 56895b1991809a26bd9524717d1348b48b28d1ed
Author: izabera <izaberina@gmail.com>
Date:   Fri Jan  1 11:05:06 +0100

fix several problems in dd

Diffstat:
dd.c | 66+++++++++++++++++++++++++++++-------------------------------------
1 file changed, 29 insertions(+), 37 deletions(-)
diff --git 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; }