cleanup mtd, implement jffs2write - one step closer to config preserving system upgrades

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@8444 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 303 insertions, 0 deletions

diff --git a/package/mtd/src/jffs2.c b/package/mtd/src/jffs2.c
new file mode 100644
index 000000000..7b68ae575
--- /dev/null
+++ b/package/mtd/src/jffs2.c
@@ -0,0 +1,303 @@
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <dirent.h>
+#include <unistd.h>
+#include "jffs2.h"
+#include "crc32.h"
+#include "mtd.h"
+
+#define PAD(x) (((x)+3)&~3)
+
+#define CLEANMARKER "\x85\x19\x03\x20\x0c\x00\x00\x00\xb1\xb0\x1e\xe4"
+#define JFFS2_EOF "\xde\xad\xc0\xde"
+
+static int last_ino = 0;
+static int last_version = 0;
+static char *buf = NULL;
+static int ofs = 0;
+static int outfd = 0;
+static int mtdofs = 0;
+
+static void prep_eraseblock(void);
+
+static void pad(int size)
+{
+	if ((ofs % size == 0) && (ofs < erasesize))
+		return;
+
+	if (ofs < erasesize) {
+		memset(buf + ofs, 0xff, (size - (ofs % size)));
+		ofs += (size - (ofs % size));
+	}
+	ofs = ofs % erasesize;
+	if (ofs == 0) {
+		mtd_erase_block(outfd, mtdofs);
+		write(outfd, buf, erasesize);
+		mtdofs += erasesize;
+	}
+}
+
+static inline int rbytes(void)
+{
+	return erasesize - (ofs % erasesize);
+}
+
+static inline void add_data(char *ptr, int len)
+{
+	if (ofs + len > erasesize) {
+		pad(erasesize);
+		prep_eraseblock();
+	}
+	memcpy(buf + ofs, ptr, len);
+	ofs += len;
+}
+
+static void prep_eraseblock(void)
+{
+	if (ofs > 0)
+		return;
+
+	add_data(CLEANMARKER, sizeof(CLEANMARKER) - 1);
+}
+
+static int add_dirent(char *name, char type, int parent)
+{
+	struct jffs2_raw_dirent *de;
+
+	if (ofs - erasesize < sizeof(struct jffs2_raw_dirent) + strlen(name))
+		pad(erasesize);
+
+	prep_eraseblock();
+	last_ino++;
+	memset(buf + ofs, 0, sizeof(struct jffs2_raw_dirent));
+	de = (struct jffs2_raw_dirent *) (buf + ofs);
+
+	de->magic = JFFS2_MAGIC_BITMASK;
+	de->nodetype = JFFS2_NODETYPE_DIRENT;
+	de->type = type;
+	de->name_crc = crc32(0, name, strlen(name));
+	de->ino = last_ino++;
+	de->pino = parent;
+	de->totlen = sizeof(*de) + strlen(name);
+	de->hdr_crc = crc32(0, (void *) de, sizeof(struct jffs2_unknown_node) - 4);
+	de->version = last_version++;
+	de->mctime = 0;
+	de->nsize = strlen(name);
+	de->node_crc = crc32(0, (void *) de, sizeof(*de) - 8);
+	memcpy(de->name, name, strlen(name));
+
+	ofs += sizeof(struct jffs2_raw_dirent) + de->nsize;
+	pad(4);
+
+	return de->ino;
+}
+
+static int add_dir(char *name, int parent)
+{
+	struct jffs2_raw_inode ri;
+	int inode;
+
+	inode = add_dirent(name, IFTODT(S_IFDIR), parent);
+
+	if (rbytes() < sizeof(ri))
+		pad(erasesize);
+	prep_eraseblock();
+
+	memset(&ri, 0, sizeof(ri));
+	ri.magic = JFFS2_MAGIC_BITMASK;
+	ri.nodetype = JFFS2_NODETYPE_INODE;
+	ri.totlen = sizeof(ri);
+	ri.hdr_crc = crc32(0, &ri, sizeof(struct jffs2_unknown_node) - 4);
+
+	ri.ino = inode;
+	ri.mode = S_IFDIR | 0755;
+	ri.uid = ri.gid = 0;
+	ri.atime = ri.ctime = ri.mtime = 0;
+	ri.isize = ri.csize = ri.dsize = 0;
+	ri.version = 1;
+	ri.node_crc = crc32(0, &ri, sizeof(ri) - 8);
+	ri.data_crc = 0;
+
+	add_data((char *) &ri, sizeof(ri));
+	pad(4);
+	return inode;
+}
+
+static void add_file(char *name, int parent)
+{
+	int inode, f_offset = 0, fd;
+	struct jffs2_raw_inode ri;
+	struct stat st;
+	char wbuf[4096], *fname;
+	FILE *f;
+
+	if (stat(name, &st)) {
+		fprintf(stderr, "File %s does not exist\n", name);
+		return;
+	}
+
+	fname = strrchr(name, '/');
+	if (fname)
+		fname++;
+	else
+		fname = name;
+
+	inode = add_dirent(name, IFTODT(S_IFREG), parent);
+	memset(&ri, 0, sizeof(ri));
+	ri.magic = JFFS2_MAGIC_BITMASK;
+	ri.nodetype = JFFS2_NODETYPE_INODE;
+
+	ri.ino = inode;
+	ri.mode = st.st_mode;
+	ri.uid = ri.gid = 0;
+	ri.atime = st.st_atime;
+	ri.ctime = st.st_ctime;
+	ri.mtime = st.st_mtime;
+	ri.isize = st.st_size;
+	ri.compr = 0;
+	ri.usercompr = 0;
+
+	fd = open(name, 0);
+	if (fd <= 0) {
+		fprintf(stderr, "File %s does not exist\n", name);
+		return;
+	}
+
+	for (;;) {
+		int len = 0;
+
+		for (;;) {
+			len = rbytes() - sizeof(ri);
+			if (len > 128)
+				break;
+
+			pad(erasesize);
+			prep_eraseblock();
+		}
+
+		if (len > sizeof(wbuf))
+			len = sizeof(wbuf);
+
+		len = read(fd, wbuf, len);
+		if (len <= 0)
+			break;
+
+		ri.totlen = sizeof(ri) + len;
+		ri.hdr_crc = crc32(0, &ri, sizeof(struct jffs2_unknown_node) - 4);
+		ri.version = ++last_version;
+		ri.offset = f_offset;
+		ri.csize = ri.dsize = len;
+		ri.node_crc = crc32(0, &ri, sizeof(ri) - 8);
+		ri.data_crc = crc32(0, wbuf, len);
+		f_offset += len;
+		add_data((char *) &ri, sizeof(ri));
+		add_data(wbuf, len);
+		pad(4);
+		prep_eraseblock();
+	}
+
+	close(fd);
+}
+
+int mtd_write_jffs2(char *mtd, char *filename, char *dir)
+{
+	int target_ino = 0;
+	int err = -1, fdeof = 0;
+	off_t offset;
+
+	outfd = mtd_check_open(mtd);
+	if (!outfd)
+		return -1;
+
+	if (quiet < 2)
+		fprintf(stderr, "Appending %s to jffs2 partition %s\n", filename, mtd);
+	
+	buf = malloc(erasesize);
+	if (!buf) {
+		fprintf(stderr, "Out of memory!\n");
+		goto done;
+	}
+
+	/* parse the structure of the jffs2 first
+	 * locate the directory that the file is going to be placed in */
+	for(;;) {
+		struct jffs2_unknown_node *node = (struct jffs2_unknown_node *) buf;
+		unsigned int ofs = 0;
+
+		if (read(outfd, buf, erasesize) != erasesize) {
+			fdeof = 1;
+			break;
+		}
+		mtdofs += erasesize;
+
+		if (node->magic == 0x8519) {
+			fprintf(stderr, "Error: wrong endianness filesystem\n");
+			goto done;
+		}
+
+		/* assume  no magic == end of filesystem
+		 * the filesystem will probably end with be32(0xdeadc0de) */
+		if (node->magic != 0x1985)
+			break;
+
+		while (ofs < erasesize) {
+			node = (struct jffs2_unknown_node *) (buf + ofs);
+			if (node->magic == 0x1985) {
+				ofs += PAD(node->totlen);
+				if (node->nodetype == JFFS2_NODETYPE_DIRENT) {
+					struct jffs2_raw_dirent *de = (struct jffs2_raw_dirent *) node;
+					
+					/* is this the right directory name and is it a subdirectory of / */
+					if ((de->pino == 1) && !strncmp(de->name, dir, de->nsize))
+						target_ino = de->ino;
+
+					/* store the last inode and version numbers for adding extra files */
+					if (last_ino < de->ino)
+						last_ino = de->ino;
+					if (last_version < de->version)
+						last_version = de->version;
+				}
+			} else {
+				ofs = ~0;
+			}
+		}
+	}
+
+	if (fdeof) {
+		fprintf(stderr, "Error: No room for additional data\n");
+		goto done;
+	}
+
+	/* jump back one eraseblock */
+	mtdofs -= erasesize;
+	lseek(outfd, mtdofs, SEEK_SET);
+
+	ofs = 0;
+
+	if (!last_ino)
+		last_ino = 1;
+
+	if (!target_ino)
+		target_ino = add_dir(dir, 1);
+
+	add_file(filename, target_ino);
+	pad(erasesize);
+
+	/* add eof marker, pad to eraseblock size and write the data */
+	add_data(JFFS2_EOF, sizeof(JFFS2_EOF) - 1);
+	pad(erasesize);
+
+	err = 0;
+
+done:
+	close(outfd);
+	if (buf)
+		free(buf);
+
+	return err;
+}