Adding upstream version 2:4.0.4.upstream/2%4.0.4upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 292 insertions, 0 deletions

diff --git a/local/procio.c b/local/procio.c
new file mode 100644
index 0000000..bbd7c84
--- /dev/null
+++ b/local/procio.c
@@ -0,0 +1,292 @@
+/*
+ * procio.c -- Replace stdio for read and write on files below
+ * proc to be able to read and write large buffers as well.
+ *
+ * Copyright (C) 2017 Werner Fink
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifndef _GNU_SOURCE
+# define _GNU_SOURCE
+#endif
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+typedef struct pcookie {
+	char	*buf;
+	size_t	count;
+	size_t	length;
+	off_t	offset;
+	int	fd;
+	int	delim;
+	int	final:1;
+} pcookie_t;
+
+static ssize_t proc_read(void *, char *, size_t);
+static ssize_t proc_write(void *, const char *, size_t);
+static int proc_close(void *);
+
+__extension__
+static cookie_io_functions_t procio = {
+    .read  = proc_read,
+    .write = proc_write,
+    .seek  = NULL,
+    .close = proc_close,
+};
+
+FILE *fprocopen(const char *path, const char *mode)
+{
+	pcookie_t *cookie = NULL;
+	FILE *handle = NULL;
+	mode_t flags = 0;
+	size_t len = 0;
+	int c, delim;
+
+	if (!mode || !(len = strlen(mode))) {
+		errno = EINVAL;
+		goto out;
+	}
+
+	/* No append mode possible */
+	switch (mode[0]) {
+	case 'r':
+		flags |= O_RDONLY;
+		break;
+	case 'w':
+		flags |= O_WRONLY|O_TRUNC;
+		break;
+	default:
+		errno = EINVAL;
+		goto out;
+	}
+
+	delim = ',';				/* default delimeter is the comma */
+	for (c = 1; c < len; c++) {
+		switch (mode[c]) {
+		case '\0':
+			break;
+		case '+':
+			errno = EINVAL;
+			goto out;
+		case 'e':
+			flags |= O_CLOEXEC;
+			continue;
+		case 'b':
+		case 'm':
+		case 'x':
+			/* ignore this */
+			continue;
+		default:
+			if (mode[c] == ' ' || (mode[c] >= ',' && mode[c] <= '.') || mode[c] == ':')
+				delim = mode[c];
+			else {
+				errno = EINVAL;
+				goto out;
+			}
+			break;
+		}
+		break;
+	}
+
+	cookie = (pcookie_t *)malloc(sizeof(pcookie_t));
+	if (!cookie)
+		goto out;
+	cookie->count = BUFSIZ;
+	cookie->buf = (char *)malloc(cookie->count);
+	if (!cookie->buf) {
+		int errsv = errno;
+		free(cookie);
+		errno = errsv;
+		goto out;
+	}
+	cookie->final = 0;
+	cookie->offset = 0;
+	cookie->length = 0;
+	cookie->delim = delim;
+
+	cookie->fd = openat(AT_FDCWD, path, flags);
+	if (cookie->fd < 0) {
+		int errsv = errno;
+		free(cookie->buf);
+		free(cookie);
+		errno = errsv;
+		goto out;
+	}
+
+	handle = fopencookie(cookie, mode, procio);
+	if (!handle) {
+		int errsv = errno;
+		close(cookie->fd);
+		free(cookie->buf);
+		free(cookie);
+		errno = errsv;
+		goto out;
+	}
+out:
+	return handle;
+}
+
+static
+ssize_t proc_read(void *c, char *buf, size_t count)
+{
+	pcookie_t *cookie = c;
+	ssize_t len = -1;
+	void *ptr;
+
+	if (cookie->count < count) {
+		ptr = realloc(cookie->buf, count);
+		if (!ptr)
+			goto out;
+		cookie->buf = ptr;
+		cookie->count = count;
+	}
+
+	while (!cookie->final) {
+		len = read(cookie->fd, cookie->buf, cookie->count);
+
+		if (len <= 0) {
+			if (len == 0) {
+				/* EOF */
+				cookie->final = 1;
+				cookie->buf[cookie->length] = '\0';
+				break;
+			}
+			goto out;		/* error or done */
+		}
+
+		cookie->length = len;
+
+		if (cookie->length < cookie->count)
+			continue;
+
+		/* Likly to small buffer here */
+
+		lseek(cookie->fd, 0, SEEK_SET);	/* reset for a retry */
+
+		ptr = realloc(cookie->buf, cookie->count += BUFSIZ);
+		if (!ptr)
+			goto out;
+		cookie->buf = ptr;
+	}
+
+	len = count;
+	if (cookie->length - cookie->offset < len)
+		len = cookie->length - cookie->offset;
+
+	if (len < 0)
+		len = 0;
+
+	if (len) {
+		(void)memcpy(buf, cookie->buf+cookie->offset, len);
+		cookie->offset += len;
+	} else
+		len = EOF;
+out:
+	return len;
+}
+
+#define LINELEN	4096
+
+static
+ssize_t proc_write(void *c, const char *buf, size_t count)
+{
+	pcookie_t *cookie = c;
+	ssize_t len = -1;
+	void *ptr;
+
+	if (!count) {
+		len = 0;
+		goto out;
+	}
+
+						    /* NL is the final input */
+	cookie->final = memrchr(buf, '\n', count) ? 1 : 0;
+
+	while (cookie->count < cookie->offset + count) {
+		ptr = realloc(cookie->buf, cookie->count += count);
+		if (!ptr)
+			goto out;
+		cookie->buf = ptr;
+	}
+
+	len = count;
+	(void)memcpy(cookie->buf+cookie->offset, buf, count);
+	cookie->offset += count;
+
+	if (cookie->final) {
+		len = write(cookie->fd, cookie->buf, cookie->offset);
+		if (len < 0 && errno == EINVAL) {
+			size_t offset;
+			off_t amount;
+			char *token;
+			/*
+			 * Oops buffer might be to large, split buffer into
+			 * pieces at delimeter if provided
+			 */
+			if (!cookie->delim)
+				goto out;		/* Hey dude?! */
+			offset = 0;
+			do {
+				token = NULL;
+				if (cookie->offset > LINELEN)
+					token = (char*)memrchr(cookie->buf+offset, cookie->delim, LINELEN);
+				else
+					token = (char*)memrchr(cookie->buf+offset, '\n', cookie->offset);
+				if (token)
+					*token = '\n';
+				else {
+					errno = EINVAL;
+					len = -1;
+					goto out;	/* Wrong/Missing delimeter? */
+				}
+				if (offset > 0)
+					lseek(cookie->fd, 1, SEEK_CUR);
+
+				amount = token-(cookie->buf+offset)+1;
+				ptr = cookie->buf+offset;
+
+				len = write(cookie->fd, ptr, amount);
+				if (len < 1  || len >= cookie->offset)
+					break;
+
+				offset += len;
+				cookie->offset -= len;
+
+			} while (cookie->offset > 0);
+		}
+		if (len > 0)
+			len = count;
+	}
+out:
+	return len;
+}
+
+static
+int proc_close(void *c)
+{
+	pcookie_t *cookie = c;
+	close(cookie->fd);
+	free(cookie->buf);
+	free(cookie);
+	return 0;
+}