1 files changed, 415 insertions, 0 deletions
diff --git a/usr.bin/rcs/buf.c b/usr.bin/rcs/buf.c
new file mode 100644
index 00000000000..e4e20060a39
--- /dev/null
+++ b/usr.bin/rcs/buf.c
@@ -0,0 +1,415 @@
+/*	$OpenBSD: buf.c,v 1.1 2006/04/26 02:55:13 joris Exp $	*/
+/*
+ * Copyright (c) 2003 Jean-Francois Brousseau <jfb@openbsd.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+ * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL  DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "includes.h"
+
+#include "buf.h"
+#include "xmalloc.h"
+#include "worklist.h"
+
+#define BUF_INCR	128
+
+struct rcs_buf {
+	u_int	cb_flags;
+
+	/* buffer handle and size */
+	u_char	*cb_buf;
+	size_t	 cb_size;
+
+	/* start and length of valid data in buffer */
+	u_char	*cb_cur;
+	size_t	 cb_len;
+};
+
+#define SIZE_LEFT(b)	(b->cb_size - (size_t)(b->cb_cur - b->cb_buf) \
+			    - b->cb_len)
+
+static void	rcs_buf_grow(BUF *, size_t);
+
+/*
+ * rcs_buf_alloc()
+ *
+ * Create a new buffer structure and return a pointer to it.  This structure
+ * uses dynamically-allocated memory and must be freed with rcs_buf_free(),
+ * once the buffer is no longer needed.
+ */
+BUF *
+rcs_buf_alloc(size_t len, u_int flags)
+{
+	BUF *b;
+
+	b = xmalloc(sizeof(*b));
+	/* Postpone creation of zero-sized buffers */
+	if (len > 0)
+		b->cb_buf = xcalloc(1, len);
+	else
+		b->cb_buf = NULL;
+
+	b->cb_flags = flags;
+	b->cb_size = len;
+	b->cb_cur = b->cb_buf;
+	b->cb_len = 0;
+
+	return (b);
+}
+
+/*
+ * rcs_buf_load()
+ *
+ * Open the file specified by <path> and load all of its contents into a
+ * buffer.
+ * Returns the loaded buffer on success.
+ */
+BUF *
+rcs_buf_load(const char *path, u_int flags)
+{
+	int fd;
+	ssize_t ret;
+	size_t len;
+	u_char *bp;
+	struct stat st;
+	BUF *buf;
+
+	if ((fd = open(path, O_RDONLY, 0600)) == -1) {
+		warn("%s", path);
+		return (NULL);
+	}
+
+	if (fstat(fd, &st) == -1)
+		err(1, "rcs_buf_load: fstat: %s", path);
+
+	buf = rcs_buf_alloc((size_t)st.st_size, flags);
+	for (bp = buf->cb_cur; ; bp += (size_t)ret) {
+		len = SIZE_LEFT(buf);
+		ret = read(fd, bp, len);
+		if (ret == -1) {
+			rcs_buf_free(buf);
+			err(1, "rcs_buf_load: read: %s", strerror(errno));
+		} else if (ret == 0)
+			break;
+
+		buf->cb_len += (size_t)ret;
+	}
+
+	(void)close(fd);
+
+	return (buf);
+}
+
+/*
+ * rcs_buf_free()
+ *
+ * Free the buffer <b> and all associated data.
+ */
+void
+rcs_buf_free(BUF *b)
+{
+	if (b->cb_buf != NULL)
+		xfree(b->cb_buf);
+	xfree(b);
+}
+
+/*
+ * rcs_buf_release()
+ *
+ * Free the buffer <b>'s structural information but do not free the contents
+ * of the buffer.  Instead, they are returned and should be freed later using
+ * free().
+ */
+void *
+rcs_buf_release(BUF *b)
+{
+	u_char *tmp;
+
+	tmp = b->cb_buf;
+	xfree(b);
+	return (tmp);
+}
+
+/*
+ * rcs_buf_empty()
+ *
+ * Empty the contents of the buffer <b> and reset pointers.
+ */
+void
+rcs_buf_empty(BUF *b)
+{
+	memset(b->cb_buf, 0, b->cb_size);
+	b->cb_cur = b->cb_buf;
+	b->cb_len = 0;
+}
+
+/*
+ * rcs_buf_set()
+ *
+ * Set the contents of the buffer <b> at offset <off> to the first <len>
+ * bytes of data found at <src>.  If the buffer was not created with
+ * BUF_AUTOEXT, as many bytes as possible will be copied in the buffer.
+ */
+ssize_t
+rcs_buf_set(BUF *b, const void *src, size_t len, size_t off)
+{
+	size_t rlen = 0;
+
+	if (b->cb_size < (len + off)) {
+		if ((b->cb_flags & BUF_AUTOEXT)) {
+			rcs_buf_grow(b, len + off - b->cb_size);
+			rlen = len + off;
+		} else {
+			rlen = b->cb_size - off;
+		}
+	} else {
+		rlen = len;
+	}
+
+	b->cb_len = rlen;
+	memcpy((b->cb_buf + off), src, rlen);
+
+	if (b->cb_len == 0) {
+		b->cb_cur = b->cb_buf + off;
+		b->cb_len = rlen;
+	}
+
+	return (rlen);
+}
+
+/*
+ * rcs_buf_putc()
+ *
+ * Append a single character <c> to the end of the buffer <b>.
+ */
+void
+rcs_buf_putc(BUF *b, int c)
+{
+	u_char *bp;
+
+	bp = b->cb_cur + b->cb_len;
+	if (bp == (b->cb_buf + b->cb_size)) {
+		/* extend */
+		if (b->cb_flags & BUF_AUTOEXT)
+			rcs_buf_grow(b, (size_t)BUF_INCR);
+		else
+			errx(1, "rcs_buf_putc failed");
+
+		/* the buffer might have been moved */
+		bp = b->cb_cur + b->cb_len;
+	}
+	*bp = (u_char)c;
+	b->cb_len++;
+}
+
+/*
+ * rcs_buf_getc()
+ *
+ * Return u_char at buffer position <pos>.
+ *
+ */
+u_char
+rcs_buf_getc(BUF *b, size_t pos)
+{
+	return (b->cb_cur[pos]);
+}
+
+/*
+ * rcs_buf_append()
+ *
+ * Append <len> bytes of data pointed to by <data> to the buffer <b>.  If the
+ * buffer is too small to accept all data, it will attempt to append as much
+ * data as possible, or if the BUF_AUTOEXT flag is set for the buffer, it
+ * will get resized to an appropriate size to accept all data.
+ * Returns the number of bytes successfully appended to the buffer.
+ */
+ssize_t
+rcs_buf_append(BUF *b, const void *data, size_t len)
+{
+	size_t left, rlen;
+	u_char *bp, *bep;
+
+	bp = b->cb_cur + b->cb_len;
+	bep = b->cb_buf + b->cb_size;
+	left = bep - bp;
+	rlen = len;
+
+	if (left < len) {
+		if (b->cb_flags & BUF_AUTOEXT) {
+			rcs_buf_grow(b, len - left);
+			bp = b->cb_cur + b->cb_len;
+		} else
+			rlen = bep - bp;
+	}
+
+	memcpy(bp, data, rlen);
+	b->cb_len += rlen;
+
+	return (rlen);
+}
+
+/*
+ * rcs_buf_fappend()
+ *
+ */
+ssize_t
+rcs_buf_fappend(BUF *b, const char *fmt, ...)
+{
+	ssize_t ret;
+	char *str;
+	va_list vap;
+
+	va_start(vap, fmt);
+	ret = vasprintf(&str, fmt, vap);
+	va_end(vap);
+
+	if (ret == -1)
+		errx(1, "rcs_buf_fappend: failed to format data");
+
+	ret = rcs_buf_append(b, str, (size_t)ret);
+	xfree(str);
+	return (ret);
+}
+
+/*
+ * rcs_buf_len()
+ *
+ * Returns the size of the buffer that is being used.
+ */
+size_t
+rcs_buf_len(BUF *b)
+{
+	return (b->cb_len);
+}
+
+/*
+ * rcs_buf_write_fd()
+ *
+ * Write the contents of the buffer <b> to the specified <fd>
+ */
+int
+rcs_buf_write_fd(BUF *b, int fd)
+{
+	u_char *bp;
+	size_t len;
+	ssize_t ret;
+
+	len = b->cb_len;
+	bp = b->cb_cur;
+
+	do {
+		ret = write(fd, bp, len);
+		if (ret == -1) {
+			if (errno == EINTR || errno == EAGAIN)
+				continue;
+			return (-1);
+		}
+
+		len -= (size_t)ret;
+		bp += (size_t)ret;
+	} while (len > 0);
+
+	return (0);
+}
+
+/*
+ * rcs_buf_write()
+ *
+ * Write the contents of the buffer <b> to the file whose path is given in
+ * <path>.  If the file does not exist, it is created with mode <mode>.
+ */
+int
+rcs_buf_write(BUF *b, const char *path, mode_t mode)
+{
+	int fd;
+ open:
+	if ((fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, mode)) == -1) {
+		if (errno == EACCES && unlink(path) != -1)
+			goto open;
+		else
+			err(1, "open: `%s'", path);
+	}
+
+	if (rcs_buf_write_fd(b, fd) == -1) {
+		(void)unlink(path);
+		errx(1, "rcs_buf_write: rcs_buf_write_fd: `%s'", path);
+	}
+
+	if (fchmod(fd, mode) < 0)
+		warn("permissions not set on file %s", path);
+
+	(void)close(fd);
+
+	return (0);
+}
+
+/*
+ * rcs_buf_write_stmp()
+ *
+ * Write the contents of the buffer <b> to a temporary file whose path is
+ * specified using <template> (see mkstemp.3). NB. This function will modify
+ * <template>, as per mkstemp
+ */
+void
+rcs_buf_write_stmp(BUF *b, char *template, mode_t mode)
+{
+	int fd;
+
+	if ((fd = mkstemp(template)) == -1)
+		err(1, "mkstemp: `%s'", template);
+
+#if defined(RCSPROG)
+	rcs_worklist_add(template, &rcs_temp_files);
+#endif
+
+	if (rcs_buf_write_fd(b, fd) == -1) {
+		(void)unlink(template);
+		errx(1, "rcs_buf_write_stmp: rcs_buf_write_fd: `%s'", template);
+	}
+
+	if (fchmod(fd, mode) < 0)
+		warn("permissions not set on temporary file %s",
+		    template);
+
+	(void)close(fd);
+}
+
+/*
+ * rcs_buf_grow()
+ *
+ * Grow the buffer <b> by <len> bytes.  The contents are unchanged by this
+ * operation regardless of the result.
+ */
+static void
+rcs_buf_grow(BUF *b, size_t len)
+{
+	void *tmp;
+	size_t diff;
+
+	diff = b->cb_cur - b->cb_buf;
+	tmp = xrealloc(b->cb_buf, 1, b->cb_size + len);
+	b->cb_buf = tmp;
+	b->cb_size += len;
+
+	/* readjust pointers in case the buffer moved in memory */
+	b->cb_cur = b->cb_buf + diff;
+}