memzap

commit 06aef97ceacf6506da8fc66e51735ad09cc88556
parent d533827b53eeeb8b54de589694f41c13d88f0bdd
Author: sin <sin@2f30.org>
Date:   Sun,  3 Mar 2013 15:55:25 +0000

mdiff: Fix bugs and add mdiff_read_diff()

Diffstat:
M
docs/mdiff-fmt
 | 
4
+++-
M
mdiff.c
 | 
65
++++++++++++++++++++++++++++++++++++++++++++++++++++++-----------
M
proto.h
 | 
10
+++++++---

3 files changed, 64 insertions(+), 15 deletions(-)
diff --git a/docs/mdiff-fmt b/docs/mdiff-fmt
@@ -3,9 +3,11 @@ File format of the mdiff files
 
 struct mdiff_hdr {
        /* MDIFF\0 */
-       char magic[6];
+       char magic[8];
        /* Number of memory diff regions */
        uint32_t nregions;
+       /* Block size */
+       uint32_t blksize;
 };
 
 struct mdiff_region {
diff --git a/mdiff.c b/mdiff.c
@@ -18,7 +18,7 @@ create_mdiff(const char *path)
 {
 	int fd;
 
-	fd = open(path, O_RDWR);
+	fd = open(path, O_CREAT | O_RDWR | O_TRUNC, 0644);
 	if (fd < 0)
 		errx(1, "%s: %s", path, strerror(errno));
 	return fd;
@@ -38,23 +38,24 @@ close_mdiff(int fd)
 	return 0;
 }
 
-int
+struct mdiff_hdr *
 parse_mdiff_hdr(int fd)
 {
-	struct mdiff_hdr hdr;
+	struct mdiff_hdr *hdr;
 	ssize_t ret;
 
 	if (fd < 0)
-		return -EINVAL;
+		return NULL;
 
-	ret = read(fd, &hdr, sizeof(hdr));
-	if (ret != sizeof(hdr))
+	hdr = xmalloc(sizeof(*hdr));
+	ret = read(fd, hdr, sizeof(*hdr));
+	if (ret != sizeof(*hdr))
 		err(1, "read");
-	if (memcmp(hdr.magic, "MDIFF", sizeof(hdr.magic)))
-		return -EINVAL;
-	if (!hdr.nregions)
-		return -EINVAL;
-	return 0;
+	if (strncmp(hdr->magic, "MDIFF", 5))
+		return NULL;
+	if (!hdr->nregions)
+		return NULL;
+	return hdr;
 }
 
 int
@@ -88,6 +89,48 @@ mdiff_start_diff(int fd)
 	return 0;
 }
 
+struct mdiff_region *
+mdiff_read_diff(int fd, struct mdiff_hdr *hdr, uint32_t region)
+{
+	int ret;
+	off_t offset;
+	struct mdiff_region *mdiff;
+	uint32_t i;
+	uint32_t len;
+
+	if (fd < 0 || !hdr)
+		return NULL;
+
+	offset = sizeof(*hdr);
+	ret = lseek(fd, offset, SEEK_SET);
+	if (ret < 0)
+		err(1, "lseek");
+	mdiff = xmalloc(sizeof(*mdiff));
+	for (i = 0; i < region; i++) {
+		ret = read(fd, mdiff, sizeof(*mdiff));
+		if (ret != sizeof(*mdiff))
+			err(1, "read");
+		offset += sizeof(*mdiff);
+		offset += mdiff->len;
+		ret = lseek(fd, offset, SEEK_SET);
+		if (ret < 0)
+			err(1, "lseek");
+	}
+
+	ret = read(fd, mdiff, sizeof(*mdiff));
+	if (ret != sizeof(*mdiff))
+		err(1, "mdiff");
+	ret = lseek(fd, offset, SEEK_SET);
+	if (ret < 0)
+		err(1, "lseek");
+	len = mdiff->len;
+	mdiff = xrealloc(mdiff, sizeof(*mdiff) + len);
+	ret = read(fd, mdiff, sizeof(*mdiff) + len);
+	if ((size_t)ret != sizeof(*mdiff) + len)
+		err(1, "read");
+	return mdiff;
+}
+
 int
 mdiff_append_rdiff(int fd, struct mem_region_diff *rdiff)
 {
diff --git a/proto.h b/proto.h
@@ -101,10 +101,12 @@ struct mem_tree_entry {
 RB_HEAD(mem_tree, mem_tree_entry);
 
 struct mdiff_hdr {
-       /* MDIFF\0 */
-       char magic[6];
+       /* MDIFF */
+       char magic[8];
        /* Number of memory diff regions */
        uint32_t nregions;
+	/* Block size */
+	uint32_t blksize;
 };
 
 struct mdiff_region {
@@ -159,9 +161,11 @@ void readmem(pid_t pid, void *buf, void *offset, size_t size);
 int open_mdiff(const char *path);
 int create_mdiff(const char *path);
 int close_mdiff(int fd);
-int parse_mdiff_hdr(int fd);
+struct mdiff_hdr *parse_mdiff_hdr(int fd);
 int mdiff_insert_hdr(int fd, struct mdiff_hdr *hdr);
 int mdiff_start_diff(int fd);
+struct mdiff_region *mdiff_read_diff(int fd, struct mdiff_hdr *hdr,
+				     uint32_t region);
 int mdiff_append_rdiff(int fd, struct mem_region_diff *rdiff);
 
 #endif