diff options
Diffstat (limited to 'libarchive/archive_read_open_fd.c')
| -rw-r--r-- | libarchive/archive_read_open_fd.c | 87 |
1 files changed, 39 insertions, 48 deletions
diff --git a/libarchive/archive_read_open_fd.c b/libarchive/archive_read_open_fd.c index 9660da8..d8f6572 100644 --- a/libarchive/archive_read_open_fd.c +++ b/libarchive/archive_read_open_fd.c @@ -53,17 +53,13 @@ __FBSDID("$FreeBSD: head/lib/libarchive/archive_read_open_fd.c 201103 2009-12-28 struct read_fd_data { int fd; size_t block_size; - char can_skip; + char use_lseek; void *buffer; }; static int file_close(struct archive *, void *); static ssize_t file_read(struct archive *, void *, const void **buff); -#if ARCHIVE_API_VERSION < 2 -static ssize_t file_skip(struct archive *, void *, size_t request); -#else -static off_t file_skip(struct archive *, void *, off_t request); -#endif +static int64_t file_skip(struct archive *, void *, int64_t request); int archive_read_open_fd(struct archive *a, int fd, size_t block_size) @@ -78,7 +74,7 @@ archive_read_open_fd(struct archive *a, int fd, size_t block_size) return (ARCHIVE_FATAL); } - mine = (struct read_fd_data *)malloc(sizeof(*mine)); + mine = (struct read_fd_data *)calloc(1, sizeof(*mine)); b = malloc(block_size); if (mine == NULL || b == NULL) { archive_set_error(a, ENOMEM, "No memory"); @@ -98,15 +94,17 @@ archive_read_open_fd(struct archive *a, int fd, size_t block_size) */ if (S_ISREG(st.st_mode)) { archive_read_extract_set_skip_file(a, st.st_dev, st.st_ino); - mine->can_skip = 1; - } else - mine->can_skip = 0; + mine->use_lseek = 1; + } #if defined(__CYGWIN__) || defined(_WIN32) setmode(mine->fd, O_BINARY); #endif - return (archive_read_open2(a, mine, - NULL, file_read, file_skip, file_close)); + archive_read_set_read_callback(a, file_read); + archive_read_set_skip_callback(a, file_skip); + archive_read_set_close_callback(a, file_close); + archive_read_set_callback_data(a, mine); + return (archive_read_open1(a)); } static ssize_t @@ -127,55 +125,48 @@ file_read(struct archive *a, void *client_data, const void **buff) } } -#if ARCHIVE_API_VERSION < 2 -static ssize_t -file_skip(struct archive *a, void *client_data, size_t request) -#else -static off_t -file_skip(struct archive *a, void *client_data, off_t request) -#endif +static int64_t +file_skip(struct archive *a, void *client_data, int64_t request) { struct read_fd_data *mine = (struct read_fd_data *)client_data; + off_t skip = (off_t)request; off_t old_offset, new_offset; + int skip_bits = sizeof(skip) * 8 - 1; /* off_t is a signed type. */ - if (!mine->can_skip) + if (!mine->use_lseek) return (0); + /* Reduce a request that would overflow the 'skip' variable. */ + if (sizeof(request) > sizeof(skip)) { + int64_t max_skip = + (((int64_t)1 << (skip_bits - 1)) - 1) * 2 + 1; + if (request > max_skip) + skip = max_skip; + } + /* Reduce request to the next smallest multiple of block_size */ request = (request / mine->block_size) * mine->block_size; if (request == 0) return (0); + if (((old_offset = lseek(mine->fd, 0, SEEK_CUR)) >= 0) && + ((new_offset = lseek(mine->fd, skip, SEEK_CUR)) >= 0)) + return (new_offset - old_offset); + + /* If seek failed once, it will probably fail again. */ + mine->use_lseek = 0; + + /* Let libarchive recover with read+discard. */ + if (errno == ESPIPE) + return (0); + /* - * Hurray for lazy evaluation: if the first lseek fails, the second - * one will not be executed. + * There's been an error other than ESPIPE. This is most + * likely caused by a programmer error (too large request) + * or a corrupted archive file. */ - if (((old_offset = lseek(mine->fd, 0, SEEK_CUR)) < 0) || - ((new_offset = lseek(mine->fd, request, SEEK_CUR)) < 0)) - { - /* If seek failed once, it will probably fail again. */ - mine->can_skip = 0; - - if (errno == ESPIPE) - { - /* - * Failure to lseek() can be caused by the file - * descriptor pointing to a pipe, socket or FIFO. - * Return 0 here, so the compression layer will use - * read()s instead to advance the file descriptor. - * It's slower of course, but works as well. - */ - return (0); - } - /* - * There's been an error other than ESPIPE. This is most - * likely caused by a programmer error (too large request) - * or a corrupted archive file. - */ - archive_set_error(a, errno, "Error seeking"); - return (-1); - } - return (new_offset - old_offset); + archive_set_error(a, errno, "Error seeking"); + return (-1); } static int |
