diff options
Diffstat (limited to 'lseek.c')
| -rw-r--r-- | lseek.c | 121 |
1 files changed, 121 insertions, 0 deletions
@@ -0,0 +1,121 @@ +/* See LICENSE file for copyright and license details. */ +#include "internal.h" + + +void +liberror_lseek_failed(int fd, _liberror_off_t offset, int whence, const char *fname) +{ + const char *desc; + int saved_errno = errno; + switch (saved_errno) { + case EBADF: + if (fd < 0) + desc = "Negative file descriptor number specified"; + else + desc = "Unassigned file descriptor number specified"; + break; + case ESPIPE: + desc = "Unseekable file type (e.g. pipe, socket, or FIFO)"; + break; + case EOVERFLOW: + desc = "The resulting offset cannot be represented in an off_t; " + "consider compiling with _FILE_OFFSET_BITS=64"; + break; + case EINVAL: + if (whence == SEEK_SET || whence == SEEK_END || whence == SEEK_CUR) { + if (offset < 0) + desc = "Attempted to seek to a position before the beginning of the file"; + else if (offset > 0) + desc = "Attempted to seek beyond the end of the device"; + else if (whence == SEEK_SET) + desc = "Failed, for unknown reason, to seek to the beginning of the file"; + else if (whence == SEEK_END) + desc = "Failed, for unknown reason, to seek to the end of the device"; + else + desc = "Failed, for unknown reason, to look up current file offset"; + } else { + desc = "Unsupported seek mode"; + if (whence == SEEK_DATA || whence == SEEK_HOLE) { +#if defined(__linux__) + if (!liberror_libc_check_kernel_version(3, 1, 0)) + desc = "Unsupported seek mode; requires Linux 3.1 or newer"; +#else +# error Unsupported kernel +#endif + } + } + break; + case ENXIO: + if (whence == SEEK_DATA) { + if (offset < 0) { + desc = "Attempted seek for data beginning at an offset before the beginning of the file"; + } else { + desc = "Seeking for data from a hold at the end of the file, or at or after the end of the file"; + } + } else if (whence == SEEK_HOLE) { + if (offset < 0) { + desc = "Attempted seek for a hole beginning at an offset before the beginning of the file"; + } else { + desc = "Attempted seek for a hole from the end of the file, or after it's end"; + } + } + break; + default: + desc = ""; + break; + } + liberror_libc_set_error_one_file(desc, "sockatmark", "Seekable file", fd, fname); + errno = saved_errno; +} + + +void +liberror_lseek_short(int fd, _liberror_off_t offset, int whence, _liberror_uoff_t min, + _liberror_uoff_t max, _liberror_off_t returned, const char *fname) +{ + const char *desc; + struct liberror_error *error; + int saved_errno = errno; + liberror_save_backtrace(NULL); + if (returned < 0 || (size_t)returned < min) { + desc = "Seek resulted in a new offset in an earlier position than expected"; + } else if (returned > max) { + desc = "Seek resulted in a new offset in an beyond the expectation"; + } else { + desc = "Seek resulted in an unexpected new offset"; + } + liberror_set_error(desc, "recv", "liberror-libc", LIBERROR_LIBC_ERRROR_SHORT_SEEK); + error = liberror_get_error(); + error->details_type = LIBERROR_DETAILS_ONE_FILE; + error->details.one_file.fd = fd; + error->details.one_file.name = fname ? strdup(fname) : NULL; + error->details.one_file.role = "Seekable file"; + errno = saved_errno; +} + + +_liberror_off_t +liberror_lseek(int fd, _liberror_off_t offset, int whence, const char *fname) +{ + _liberror_off_t r = lseek(fd, offset, whence); + if (r >= 0) + return r; + liberror_save_backtrace(NULL); + liberror_lseek_failed(fd, offset, whence, fname); + return -1; +} + + +_liberror_off_t +liberror_lseek_require(int fd, _liberror_off_t offset, int whence, _liberror_uoff_t min, _liberror_uoff_t max, const char *fname) +{ + _liberror_off_t r = lseek(fd, offset, whence); + if (r >= 0 && (_liberror_uoff_t)r >= min && (_liberror_uoff_t)r <= max) + return r; + liberror_save_backtrace(NULL); + if (r < 0) + liberror_lseek_failed(fd, offset, whence, fname); + else + liberror_lseek_short(fd, offset, whence, min, max, r, fname); + return -1; +} |