X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=fd.c;h=1c67f22bb284ab11ffda80bb90c0693661b0328c;hp=f9b3d9d003abe88599f437bcc1aa46424bc99dc8;hb=337d7784b0f8bc30b1fa9af56ace503acd97d40d;hpb=61250cf03241bf73662dac3753e44660a572fa2a

diff --git a/fd.c b/fd.c
index f9b3d9d0..1c67f22b 100644
--- a/fd.c
+++ b/fd.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2006-2007 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2006-2009 Andre Noll <maan@systemlinux.org>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -14,6 +14,70 @@
 
 #include "para.h"
 #include "error.h"
+#include "string.h"
+/**
+ * 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 == -1)
+			return -ERRNO_TO_PARA_ERROR(errno);
+		*len += ret;
+	}
+	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.
+ * \param max_bytes_per_write Do not write more than that many bytes at once.
+ *
+ * If \a max_bytes_per_write is non-zero, do not send more than that many bytes
+ * per write().
+ *
+ * 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 max_bytes_per_write)
+{
+	size_t written = 0;
+	int ret = 0;
+
+	while (written < len) {
+		size_t num = len - written;
+
+		if (max_bytes_per_write && max_bytes_per_write < num)
+			num = max_bytes_per_write;
+		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;
+}
 
 /**
  * Check whether a file exists.
@@ -60,6 +124,24 @@ int para_select(int n, fd_set *readfds, fd_set *writefds,
 	return ret;
 }
 
+/**
+ * Set a file descriptor to blocking mode.
+ *
+ * \param fd The file descriptor.
+ *
+ * \return Standard.
+ */
+__must_check int mark_fd_blocking(int fd)
+{
+	int flags = fcntl(fd, F_GETFL);
+	if (flags < 0)
+		return -ERRNO_TO_PARA_ERROR(errno);
+	flags = fcntl(fd, F_SETFL, ((long)flags) & ~O_NONBLOCK);
+	if (flags < 0)
+		return -ERRNO_TO_PARA_ERROR(errno);
+	return 1;
+}
+
 /**
  * Set a file descriptor to non-blocking mode.
  *
@@ -67,7 +149,7 @@ int para_select(int n, fd_set *readfds, fd_set *writefds,
  *
  * \return Standard.
  */
-int mark_fd_nonblock(int fd)
+__must_check int mark_fd_nonblocking(int fd)
 {
 	int flags = fcntl(fd, F_GETFL);
 	if (flags < 0)
@@ -92,11 +174,7 @@ int mark_fd_nonblock(int fd)
 */
 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);
@@ -111,16 +189,16 @@ void para_fd_set(int fd, fd_set *fds, int *max_fileno)
 }
 
 /**
-* Paraslash's wrapper for fgets(3).
-
-* \param line Pointer to the buffer to store the line.
-* \param size The size of the buffer given by \a line.
-* \param f The stream to read from.
-*
-* \return Unlike the standard fgets() function, an integer value
-* is returned. On success, this function returns 1. On errors, -E_FGETS
-* is returned. A zero return value indicates an end of file condition.
-*/
+ * Paraslash's wrapper for fgets(3).
+ *
+ * \param line Pointer to the buffer to store the line.
+ * \param size The size of the buffer given by \a line.
+ * \param f The stream to read from.
+ *
+ * \return Unlike the standard fgets() function, an integer value
+ * is returned. On success, this function returns 1. On errors, -E_FGETS
+ * is returned. A zero return value indicates an end of file condition.
+ */
 __must_check int para_fgets(char *line, int size, FILE *f)
 {
 again:
@@ -147,19 +225,26 @@ again:
  * \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);
 }
 
 /**
@@ -242,9 +327,10 @@ int para_opendir(const char *dirname, DIR **dir, int *cwd)
 	if (*dir)
 		return 1;
 	ret = -ERRNO_TO_PARA_ERROR(errno);
-/* Ignore return value of fchdir() and close(). We're busted anyway. */
-	if (cwd)
-		fchdir(*cwd);
+	/* Ignore return value of fchdir() and close(). We're busted anyway. */
+	if (cwd) {
+		int __a_unused ret2 = fchdir(*cwd); /* STFU, gcc */
+	}
 close_cwd:
 	if (cwd)
 		close(*cwd);
@@ -281,14 +367,19 @@ int para_mkdir(const char *path, mode_t mode)
 }
 
 /**
- * Map a file into memory.
+ * 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 obj On success, the mapping is returned here.
+ * \param map On success, the mapping is returned here.
+ * \param size size of the mapping.
+ * \param fd_ptr The file descriptor of the mapping.
  *
- * \return Positive on success, negative on errors. Possible errors include: \p
- * E_FSTAT, any errors returned by para_open(), \p E_EMPTY, \p E_MMAP.
+ * 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 para_open(), mmap(2).
  */
@@ -314,17 +405,7 @@ int mmap_full_file(const char *path, int open_mode, void **map,
 		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);
@@ -345,17 +426,19 @@ out:
  */
 int para_munmap(void *start, size_t length)
 {
+	int err;
 	if (munmap(start, length) >= 0)
 		return 1;
+	err = errno;
 	PARA_ERROR_LOG("munmap (%p/%zu) failed: %s\n", start, length,
-		strerror(errno));
-	return -E_MUNMAP;
+		strerror(err));
+	return -ERRNO_TO_PARA_ERROR(err);
 }
 
 /**
- * check a file descriptor for writability
+ * Check a file descriptor for writability.
  *
- * \param fd the file descriptor
+ * \param fd The file descriptor.
  *
  * \return positive if fd is ready for writing, zero if it isn't, negative if
  * an error occurred.
@@ -376,3 +459,86 @@ again:
 		goto again;
 	return ret;
 }
+
+/**
+ * Ensure that file descriptors 0, 1, and 2 are valid.
+ *
+ * Common approach that opens /dev/null until it gets a file descriptor greater
+ * than two.
+ *
+ * \sa okir's Black Hats Manual.
+ */
+void valid_fd_012(void)
+{
+	while (1) {
+		int fd = open("/dev/null", O_RDWR);
+		if (fd < 0)
+			exit(EXIT_FAILURE);
+		if (fd > 2) {
+			close(fd);
+			break;
+		}
+	}
+}
+
+/**
+ * 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;
+}