+++ /dev/null
-/*
- * Copyright (C) 2006-2008 Andre Noll <maan@systemlinux.org>
- *
- * Licensed under the GPL v2. For licencing details see COPYING.
- */
-
-/** \file fd.c Helper functions for file descriptor handling. */
-
-#include <sys/types.h>
-#include <dirent.h>
-#include <sys/mman.h>
-#include <fcntl.h>
-#include <sys/select.h>
-
-#include "log.h"
-#include "osl.h"
-#include "error.h"
-#include "fd.h"
-
-/**
- * Wrapper for the write system call.
- *
- * \param fd The file descriptor to write to.
- * \param buf The buffer to write.
- * \param size The length of \a buf in bytes.
- *
- * This function writes out the given buffer and retries if an interrupt
- * occurred during the write.
- *
- * \return On success, the number of bytes written is returned, otherwise, a
- * negative error code is returned.
- *
- * \sa write(2).
- */
-static ssize_t __write(int fd, const void *buf, size_t size)
-{
- ssize_t ret;
-
- for (;;) {
- ret = write(fd, buf, size);
- if ((ret < 0) && (errno == EAGAIN || errno == EINTR))
- continue;
- return ret >= 0? ret : -ERRNO_TO_ERROR(errno);
- }
-}
-
-/**
- * Write a buffer to a file descriptor, re-write on short writes.
- *
- * \param fd The file descriptor.
- * \param buf The buffer to be sent.
- * \param len The length of \a buf.
- *
- * \return Standard. In any case, the number of bytes that have been written is
- * stored in \a len.
- */
-int write_all(int fd, const char *buf, size_t *len)
-{
- size_t total = *len;
-
- assert(total);
- *len = 0;
- while (*len < total) {
- int ret = __write(fd, buf + *len, total - *len);
- if (ret < 0)
- return ret;
- *len += ret;
- }
- return 1;
-}
-
-/**
- * Wrapper for the open(2) system call.
- *
- * \param path The filename.
- * \param flags The usual open(2) flags.
- * \param mode Specifies the permissions to use.
- *
- * The mode parameter must be specified when O_CREAT is in the flags, and is
- * ignored otherwise.
- *
- * \return The file descriptor on success, negative on errors.
- *
- * \sa open(2).
- */
-int osl_open(const char *path, int flags, mode_t mode)
-{
- int ret = open(path, flags, mode);
-
- if (ret >= 0)
- return ret;
- return -ERRNO_TO_ERROR(errno);
-}
-
-/**
- * Open a file, write the given buffer and close the file.
- *
- * \param filename Full path to the file to open.
- * \param buf The buffer to write to the file.
- * \param size The size of \a buf.
- *
- * \return Standard.
- */
-int write_file(const char *filename, const void *buf, size_t size)
-{
- int ret, fd;
-
- ret = osl_open(filename, O_WRONLY | O_CREAT | O_EXCL, 0644);
- if (ret < 0)
- return ret;
- fd = ret;
- ret = write_all(fd, buf, &size);
- if (ret < 0)
- goto out;
- ret = 1;
-out:
- close(fd);
- return ret;
-}
-
-/**
- * Open a file and map it into memory.
- *
- * \param path Name of the regular file to map.
- * \param open_mode Either \p O_RDONLY or \p O_RDWR.
- * \param map On success, the mapping is returned here.
- * \param size size of the mapping.
- * \param fd_ptr The file descriptor of the mapping.
- *
- * If \a fd_ptr is \p NULL, the file descriptor resulting from the underlying
- * open call is closed after mmap(). Otherwise the file is kept open and the
- * file descriptor is returned in \a fd_ptr.
- *
- * \return Standard.
- *
- * \sa osl_open(), mmap(2).
- */
-int mmap_full_file(const char *path, int open_mode, void **map,
- size_t *size, int *fd_ptr)
-{
- int fd, ret, mmap_prot, mmap_flags;
- struct stat file_status;
-
- if (open_mode == O_RDONLY) {
- mmap_prot = PROT_READ;
- mmap_flags = MAP_PRIVATE;
- } else {
- mmap_prot = PROT_READ | PROT_WRITE;
- mmap_flags = MAP_SHARED;
- }
- ret = osl_open(path, open_mode, 0);
- if (ret < 0)
- return ret;
- fd = ret;
- if (fstat(fd, &file_status) < 0) {
- ret = -ERRNO_TO_ERROR(errno);
- goto out;
- }
- *size = file_status.st_size;
- ret = -E_OSL_EMPTY;
- DEBUG_LOG("%s: size %zu\n", path, *size);
- if (!*size)
- goto out;
- *map = mmap(NULL, *size, mmap_prot, mmap_flags, fd, 0);
- if (*map == MAP_FAILED) {
- *map = NULL;
- ret = -E_OSL_MMAP;
- goto out;
- }
- ret = 1;
-out:
- if (ret < 0 || !fd_ptr)
- close(fd);
- else
- *fd_ptr = fd;
- return ret;
-}
-
-/**
- * A wrapper for munmap(2).
- *
- * \param start The start address of the memory mapping.
- * \param length The size of the mapping.
- *
- * \return Positive on success, \p -E_MUNMAP on errors.
- *
- * \sa munmap(2), mmap_full_file().
- */
-int osl_munmap(void *start, size_t length)
-{
- int err;
- if (munmap(start, length) >= 0)
- return 1;
- err = errno;
- ERROR_LOG("munmap (%p/%zu) failed: %s\n", start, length,
- strerror(err));
- return -ERRNO_TO_ERROR(err);
-}
-
-/**
- * Allocate a sufficiently large string and print into it.
- *
- * \param fmt A usual format string.
- *
- * Produce output according to \p fmt. No artificial bound on the length of the
- * resulting string is imposed.
- *
- * \return This function either returns a pointer to a string that must be
- * freed by the caller or \p NULL if memory allocation failed.
- *
- * \sa printf(3).
- */
-__must_check __printf_1_2 __malloc char *make_message(const char *fmt, ...)
-{
- int n;
- size_t size = 100;
- char *p = malloc(size);
-
- if (!p)
- return NULL;
- while (1) {
- char *q;
- va_list ap;
- /* Try to print in the allocated space. */
- va_start(ap, fmt);
- n = vsnprintf(p, size, fmt, ap);
- va_end(ap);
- /* If that worked, return the string. */
- if (n > -1 && n < size)
- break;
- /* Else try again with more space. */
- if (n > -1) /* glibc 2.1 */
- size = n + 1; /* precisely what is needed */
- else /* glibc 2.0 */
- size *= 2; /* twice the old size */
- q = realloc(p, size);
- if (!q) {
- free(p);
- return NULL;
- }
- p = q;
- }
- return p;
-}
-
-/**
- * A wrapper for truncate(2)
- *
- * \param path Name of the regular file to truncate
- * \param size Number of bytes to \b shave \b off
- *
- * Truncate the regular file named by \a path by \a size bytes.
- *
- * \return Standard.
- *
- * \sa truncate(2)
- */
-int truncate_file(const char *path, off_t size)
-{
- int ret;
- struct stat statbuf;
-
- ret = osl_stat(path, &statbuf);
- if (ret < 0)
- return ret;
- ret = -E_OSL_BAD_SIZE;
- if (statbuf.st_size < size)
- return ret;
- if (truncate(path, statbuf.st_size - size) < 0)
- return -ERRNO_TO_ERROR(errno);
- return 1;
-}
projects / osl.git / blobdiff