/*
- * Copyright (C) 2006-2009 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2006-2011 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 <regex.h>
#include <sys/types.h>
#include <dirent.h>
#include <sys/mman.h>
#include <fcntl.h>
-#include <sys/select.h>
+#include <sys/uio.h>
#include "para.h"
#include "error.h"
+#include "string.h"
+#include "fd.h"
/**
* Write a buffer to a file descriptor, re-write on short writes.
return 1;
}
+/**
+ * Write a buffer to a non-blocking file descriptor.
+ *
+ * \param fd The file descriptor.
+ * \param buf the buffer to write.
+ * \param len the number of bytes of \a buf.
+ *
+ * EAGAIN is not considered an error condition. For example CCID3 has a
+ * sending wait queue which fills up and is emptied asynchronously. The EAGAIN
+ * case means that there is currently no space in the wait queue, but this can
+ * change at any moment.
+ *
+ * \return Negative on errors, number of bytes written else.
+ */
+int write_nonblock(int fd, const char *buf, size_t len)
+{
+ size_t written = 0;
+ int ret = 0;
+
+ while (written < len) {
+ size_t num = len - written;
+
+ ret = write(fd, buf + written, num);
+ if (ret < 0 && errno == EAGAIN)
+ return written;
+ if (ret < 0)
+ return -ERRNO_TO_PARA_ERROR(errno);
+ written += ret;
+ }
+ return written;
+}
+
+/**
+ * Read from a non-blocking file descriptor into multiple buffers.
+ *
+ * \param fd The file descriptor to read from.
+ * \param iov Scatter/gather array used in readv().
+ * \param iovcnt Number of elements in \a iov.
+ * \param rfds An optional fd set pointer.
+ * \param num_bytes Result pointer. Contains the number of bytes read from \a fd.
+ *
+ * If \a rfds is not \p NULL and the (non-blocking) file descriptor \a fd is
+ * not set in \a rfds, this function returns early without doing anything.
+ * Otherwise The function tries to read up to \a sz bytes from \a fd. As for
+ * write_nonblock(), EAGAIN is not considered an error condition. However, EOF
+ * is.
+ *
+ * \return Zero or a negative error code. If the underlying call to readv(2)
+ * returned zero (indicating an end of file condition) or failed for some
+ * reason other than \p EAGAIN, a negative return value is returned.
+ *
+ * In any case, \a num_bytes contains the number of bytes that have been
+ * successfully read from \a fd (zero if the first readv() call failed with
+ * EAGAIN). Note that even if the function returns negative, some data might
+ * have been read before the error occurred. In this case \a num_bytes is
+ * positive.
+ *
+ * \sa \ref write_nonblock(), read(2), readv(2).
+ */
+int readv_nonblock(int fd, struct iovec *iov, int iovcnt, fd_set *rfds,
+ size_t *num_bytes)
+{
+ int ret, i, j;
+
+ *num_bytes = 0;
+ /*
+ * Avoid a shortcoming of select(): Reads from a non-blocking fd might
+ * return EAGAIN even if FD_ISSET() returns true. However, FD_ISSET()
+ * returning false definitely means that no data can currently be read.
+ * This is the common case, so it is worth to avoid the overhead of the
+ * read() system call in this case.
+ */
+ if (rfds && !FD_ISSET(fd, rfds))
+ return 0;
+
+ for (i = 0, j = 0; i < iovcnt;) {
+
+ /* fix up the first iov */
+ assert(j < iov[i].iov_len);
+ iov[i].iov_base += j;
+ iov[i].iov_len -= j;
+ ret = readv(fd, iov + i, iovcnt - i);
+ iov[i].iov_base -= j;
+ iov[i].iov_len += j;
+
+ if (ret == 0)
+ return -E_EOF;
+ if (ret < 0) {
+ if (errno == EAGAIN)
+ return 0;
+ return -ERRNO_TO_PARA_ERROR(errno);
+ }
+ *num_bytes += ret;
+ while (ret > 0) {
+ if (ret < iov[i].iov_len - j) {
+ j += ret;
+ break;
+ }
+ ret -= iov[i].iov_len - j;
+ j = 0;
+ if (++i >= iovcnt)
+ break;
+ }
+ }
+ return 0;
+}
+
+/**
+ * Read from a non-blocking file descriptor into a single buffer.
+ *
+ * \param fd The file descriptor to read from.
+ * \param buf The buffer to read data to.
+ * \param sz The size of \a buf.
+ * \param rfds \see \ref readv_nonblock().
+ * \param num_bytes \see \ref readv_nonblock().
+ *
+ * This is a simple wrapper for readv_nonblock() which uses an iovec with a single
+ * buffer.
+ *
+ * \return The return value of the underlying call to readv_nonblock().
+ */
+int read_nonblock(int fd, void *buf, size_t sz, fd_set *rfds, size_t *num_bytes)
+{
+ struct iovec iov = {.iov_base = buf, .iov_len = sz};
+ return readv_nonblock(fd, &iov, 1, rfds, num_bytes);
+}
+
+/**
+ * Read a buffer and check its content for a pattern.
+ *
+ * \param fd The file descriptor to receive from.
+ * \param pattern The expected pattern.
+ * \param bufsize The size of the internal buffer.
+ * \param rfds Passed to read_nonblock().
+ *
+ * This function tries to read at most \a bufsize bytes from the non-blocking
+ * file descriptor \a fd. If at least \p strlen(\a pattern) bytes have been
+ * received, the beginning of the received buffer is compared with \a pattern,
+ * ignoring case.
+ *
+ * \return Positive if \a pattern was received, negative on errors, zero if no data
+ * was available to read.
+ *
+ * \sa \ref read_nonblock(), \sa strncasecmp(3).
+ */
+int read_pattern(int fd, const char *pattern, size_t bufsize, fd_set *rfds)
+{
+ size_t n, len;
+ char *buf = para_malloc(bufsize + 1);
+ int ret = read_nonblock(fd, buf, bufsize, rfds, &n);
+
+ buf[n] = '\0';
+ if (ret < 0)
+ goto out;
+ ret = 0;
+ if (n == 0)
+ goto out;
+ ret = -E_READ_PATTERN;
+ len = strlen(pattern);
+ if (n < len)
+ goto out;
+ if (strncasecmp(buf, pattern, len) != 0)
+ goto out;
+ ret = 1;
+out:
+ if (ret < 0) {
+ PARA_NOTICE_LOG("%s\n", para_strerror(-ret));
+ PARA_NOTICE_LOG("recvd %zu bytes: %s\n", n, buf);
+ }
+ free(buf);
+ return ret;
+}
+
/**
* Check whether a file exists.
*
int para_select(int n, fd_set *readfds, fd_set *writefds,
struct timeval *timeout_tv)
{
- int ret, err;
- do {
+ int ret;
+ do
ret = select(n, readfds, writefds, NULL, timeout_tv);
- err = errno;
- } while (ret < 0 && err == EINTR);
+ while (ret < 0 && errno == EINTR);
if (ret < 0)
return -ERRNO_TO_PARA_ERROR(errno);
return ret;
*/
void para_fd_set(int fd, fd_set *fds, int *max_fileno)
{
-
- if (fd < 0 || fd >= FD_SETSIZE) {
- PARA_EMERG_LOG("fatal: tried to add invalid fd %d\n", fd);
- exit(EXIT_FAILURE);
- }
+ assert(fd >= 0 && fd < FD_SETSIZE);
#if 0
{
int flags = fcntl(fd, F_GETFL);
* \param flags Exactly one of MAP_SHARED and MAP_PRIVATE.
* \param fd The file to mmap from.
* \param offset Mmap start.
+ * \param map Result pointer.
*
- * \return This function either returns a valid pointer to the mapped area
- * or calls exit() on errors.
+ * \return Standard.
+ *
+ * \sa mmap(2).
*/
-void *para_mmap(size_t length, int prot, int flags, int fd, off_t offset)
+int para_mmap(size_t length, int prot, int flags, int fd, off_t offset,
+ void *map)
{
- void *ret = mmap(NULL, length, prot, flags, fd, offset);
- if (ret != MAP_FAILED)
- return ret;
- PARA_EMERG_LOG("mmap failed: %s\n", strerror(errno));
- PARA_EMERG_LOG("length: %zu, flags: %d, fd: %d, offset: %zu\n",
- length, flags, fd, (size_t)offset);
- exit(EXIT_FAILURE);
+ void **m = map;
+
+ errno = EINVAL;
+ if (!length)
+ goto err;
+ *m = mmap(NULL, length, prot, flags, fd, offset);
+ if (*m != MAP_FAILED)
+ return 1;
+err:
+ *m = NULL;
+ return -ERRNO_TO_PARA_ERROR(errno);
}
/**
* \sa getcwd(3).
*
*/
-int para_opendir(const char *dirname, DIR **dir, int *cwd)
+static int para_opendir(const char *dirname, DIR **dir, int *cwd)
{
int ret;
*
* \return Standard.
*/
-int para_fchdir(int fd)
+static int para_fchdir(int fd)
{
if (fchdir(fd) < 0)
return -ERRNO_TO_PARA_ERROR(errno);
goto out;
}
*size = file_status.st_size;
- ret = -E_EMPTY;
- PARA_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_MMAP;
- goto out;
- }
- ret = 1;
+ ret = para_mmap(*size, mmap_prot, mmap_flags, fd, 0, map);
out:
if (ret < 0 || !fd_ptr)
close(fd);
* \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.
+ * \return Standard.
*
* \sa munmap(2), mmap_full_file().
*/
int write_ok(int fd)
{
- struct timeval tv = {0, 0};
+ struct timeval tv;
fd_set wfds;
- int ret;
-again:
+
FD_ZERO(&wfds);
FD_SET(fd, &wfds);
tv.tv_sec = 0;
tv.tv_usec = 0;
- ret = select(fd + 1, NULL, &wfds, NULL, &tv);
- if (ret < 0 && errno == EINTR)
- goto again;
- return ret;
+ return para_select(fd + 1, NULL, &wfds, &tv);
}
/**
}
}
}
+
+/**
+ * Traverse the given directory recursively.
+ *
+ * \param dirname The directory to traverse.
+ * \param func The function to call for each entry.
+ * \param private_data Pointer to an arbitrary data structure.
+ *
+ * For each regular file under \a dirname, the supplied function \a func is
+ * called. The full path of the regular file and the \a private_data pointer
+ * are passed to \a func. Directories for which the calling process has no
+ * permissions to change to are silently ignored.
+ *
+ * \return Standard.
+ */
+int for_each_file_in_dir(const char *dirname,
+ int (*func)(const char *, void *), void *private_data)
+{
+ DIR *dir;
+ struct dirent *entry;
+ int cwd_fd, ret2, ret = para_opendir(dirname, &dir, &cwd_fd);
+
+ if (ret < 0)
+ return ret == -ERRNO_TO_PARA_ERROR(EACCES)? 1 : ret;
+ /* scan cwd recursively */
+ while ((entry = readdir(dir))) {
+ mode_t m;
+ char *tmp;
+ struct stat s;
+
+ if (!strcmp(entry->d_name, "."))
+ continue;
+ if (!strcmp(entry->d_name, ".."))
+ continue;
+ if (lstat(entry->d_name, &s) == -1)
+ continue;
+ m = s.st_mode;
+ if (!S_ISREG(m) && !S_ISDIR(m))
+ continue;
+ tmp = make_message("%s/%s", dirname, entry->d_name);
+ if (!S_ISDIR(m)) {
+ ret = func(tmp, private_data);
+ free(tmp);
+ if (ret < 0)
+ goto out;
+ continue;
+ }
+ /* directory */
+ ret = for_each_file_in_dir(tmp, func, private_data);
+ free(tmp);
+ if (ret < 0)
+ goto out;
+ }
+ ret = 1;
+out:
+ closedir(dir);
+ ret2 = para_fchdir(cwd_fd);
+ if (ret2 < 0 && ret >= 0)
+ ret = ret2;
+ close(cwd_fd);
+ return ret;
+}
projects / paraslash.git / blobdiff