diff options
Diffstat (limited to 'src/shared/copy.c')
| -rw-r--r-- | src/shared/copy.c | 25 |
1 files changed, 21 insertions, 4 deletions
diff --git a/src/shared/copy.c b/src/shared/copy.c index 7c3fab6901..ebd6699838 100644 --- a/src/shared/copy.c +++ b/src/shared/copy.c @@ -22,15 +22,27 @@ #include "util.h" #include "copy.h" -int copy_bytes(int fdf, int fdt) { +int copy_bytes(int fdf, int fdt, off_t max_bytes) { assert(fdf >= 0); assert(fdt >= 0); for (;;) { char buf[PIPE_BUF]; ssize_t n, k; + size_t m; - n = read(fdf, buf, sizeof(buf)); + m = sizeof(buf); + + if (max_bytes != (off_t) -1) { + + if (max_bytes <= 0) + return -E2BIG; + + if ((off_t) m > max_bytes) + m = (size_t) max_bytes; + } + + n = read(fdf, buf, m); if (n < 0) return -errno; if (n == 0) @@ -42,6 +54,11 @@ int copy_bytes(int fdf, int fdt) { return k; if (k != n) return errno ? -errno : -EIO; + + if (max_bytes != (off_t) -1) { + assert(max_bytes >= n); + max_bytes -= n; + } } return 0; @@ -84,7 +101,7 @@ static int fd_copy_regular(int df, const char *from, const struct stat *st, int if (fdt < 0) return -errno; - r = copy_bytes(fdf, fdt); + r = copy_bytes(fdf, fdt, (off_t) -1); if (r < 0) { unlinkat(dt, to, 0); return r; @@ -262,7 +279,7 @@ int copy_file(const char *from, const char *to, int flags, mode_t mode) { if (fdt < 0) return -errno; - r = copy_bytes(fdf, fdt); + r = copy_bytes(fdf, fdt, (off_t) -1); if (r < 0) { unlink(to); return r; |