1 files changed, 263 insertions, 114 deletions

diff --git a/usr/gen_init_cpio.c b/usr/gen_init_cpio.c
index af8c925e93eb..b7296edc6626 100644
--- a/usr/gen_init_cpio.c
+++ b/usr/gen_init_cpio.c
@@ -1,5 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdint.h>
+#include <stdbool.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <string.h>
@@ -19,64 +23,75 @@
 
 #define xstr(s) #s
 #define str(s) xstr(s)
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+#define CPIO_HDR_LEN 110
+#define CPIO_TRAILER "TRAILER!!!"
+#define padlen(_off, _align) (((_align) - ((_off) & ((_align) - 1))) % (_align))
 
+/* zero-padding the filename field for data alignment is limited by PATH_MAX */
+static char padding[PATH_MAX];
 static unsigned int offset;
 static unsigned int ino = 721;
 static time_t default_mtime;
+static bool do_file_mtime;
+static bool do_csum = false;
+static int outfd = STDOUT_FILENO;
+static unsigned int dalign;
 
 struct file_handler {
 	const char *type;
 	int (*handler)(const char *line);
 };
 
-static void push_string(const char *name)
+static int push_buf(const char *name, size_t name_len)
 {
-	unsigned int name_len = strlen(name) + 1;
+	ssize_t len;
+
+	len = write(outfd, name, name_len);
+	if (len != name_len)
+		return -1;
 
-	fputs(name, stdout);
-	putchar(0);
 	offset += name_len;
+	return 0;
 }
 
-static void push_pad (void)
+static int push_pad(size_t padlen)
 {
-	while (offset & 3) {
-		putchar(0);
-		offset++;
-	}
-}
+	ssize_t len = 0;
 
-static void push_rest(const char *name)
-{
-	unsigned int name_len = strlen(name) + 1;
-	unsigned int tmp_ofs;
+	if (!padlen)
+		return 0;
 
-	fputs(name, stdout);
-	putchar(0);
-	offset += name_len;
+	if (padlen < sizeof(padding))
+		len = write(outfd, padding, padlen);
+	if (len != padlen)
+		return -1;
 
-	tmp_ofs = name_len + 110;
-	while (tmp_ofs & 3) {
-		putchar(0);
-		offset++;
-		tmp_ofs++;
-	}
+	offset += padlen;
+	return 0;
 }
 
-static void push_hdr(const char *s)
+static int push_rest(const char *name, size_t name_len)
 {
-	fputs(s, stdout);
-	offset += 110;
+	ssize_t len;
+
+	len = write(outfd, name, name_len);
+	if (len != name_len)
+		return -1;
+
+	offset += name_len;
+
+	return push_pad(padlen(name_len + CPIO_HDR_LEN, 4));
 }
 
-static void cpio_trailer(void)
+static int cpio_trailer(void)
 {
-	char s[256];
-	const char name[] = "TRAILER!!!";
+	int len;
+	unsigned int namesize = sizeof(CPIO_TRAILER);
 
-	sprintf(s, "%s%08X%08X%08lX%08lX%08X%08lX"
+	len = dprintf(outfd, "%s%08X%08X%08lX%08lX%08X%08lX"
 	       "%08X%08X%08X%08X%08X%08X%08X",
-		"070701",		/* magic */
+		do_csum ? "070702" : "070701", /* magic */
 		0,			/* ino */
 		0,			/* mode */
 		(long) 0,		/* uid */
@@ -88,46 +103,58 @@ static void cpio_trailer(void)
 		0,			/* minor */
 		0,			/* rmajor */
 		0,			/* rminor */
-		(unsigned)strlen(name)+1, /* namesize */
+		namesize,		/* namesize */
 		0);			/* chksum */
-	push_hdr(s);
-	push_rest(name);
+	offset += len;
 
-	while (offset % 512) {
-		putchar(0);
-		offset++;
-	}
+	if (len != CPIO_HDR_LEN ||
+	    push_rest(CPIO_TRAILER, namesize) < 0 ||
+	    push_pad(padlen(offset, 512)) < 0)
+		return -1;
+
+	if (fsync(outfd) < 0 && errno != EINVAL)
+		return -1;
+
+	return 0;
 }
 
 static int cpio_mkslink(const char *name, const char *target,
 			 unsigned int mode, uid_t uid, gid_t gid)
 {
-	char s[256];
+	int len;
+	unsigned int namesize, targetsize = strlen(target) + 1;
 
 	if (name[0] == '/')
 		name++;
-	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
+	namesize = strlen(name) + 1;
+
+	len = dprintf(outfd, "%s%08X%08X%08lX%08lX%08X%08lX"
 	       "%08X%08X%08X%08X%08X%08X%08X",
-		"070701",		/* magic */
+		do_csum ? "070702" : "070701", /* magic */
 		ino++,			/* ino */
 		S_IFLNK | mode,		/* mode */
 		(long) uid,		/* uid */
 		(long) gid,		/* gid */
 		1,			/* nlink */
 		(long) default_mtime,	/* mtime */
-		(unsigned)strlen(target)+1, /* filesize */
+		targetsize,		/* filesize */
 		3,			/* major */
 		1,			/* minor */
 		0,			/* rmajor */
 		0,			/* rminor */
-		(unsigned)strlen(name) + 1,/* namesize */
+		namesize,		/* namesize */
 		0);			/* chksum */
-	push_hdr(s);
-	push_string(name);
-	push_pad();
-	push_string(target);
-	push_pad();
+	offset += len;
+
+	if (len != CPIO_HDR_LEN ||
+	    push_buf(name, namesize) < 0 ||
+	    push_pad(padlen(offset, 4)) < 0 ||
+	    push_buf(target, targetsize) < 0 ||
+	    push_pad(padlen(offset, 4)) < 0)
+		return -1;
+
 	return 0;
+
 }
 
 static int cpio_mkslink_line(const char *line)
@@ -151,13 +178,16 @@ static int cpio_mkslink_line(const char *line)
 static int cpio_mkgeneric(const char *name, unsigned int mode,
 		       uid_t uid, gid_t gid)
 {
-	char s[256];
+	int len;
+	unsigned int namesize;
 
 	if (name[0] == '/')
 		name++;
-	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
+	namesize = strlen(name) + 1;
+
+	len = dprintf(outfd, "%s%08X%08X%08lX%08lX%08X%08lX"
 	       "%08X%08X%08X%08X%08X%08X%08X",
-		"070701",		/* magic */
+		do_csum ? "070702" : "070701", /* magic */
 		ino++,			/* ino */
 		mode,			/* mode */
 		(long) uid,		/* uid */
@@ -169,10 +199,14 @@ static int cpio_mkgeneric(const char *name, unsigned int mode,
 		1,			/* minor */
 		0,			/* rmajor */
 		0,			/* rminor */
-		(unsigned)strlen(name) + 1,/* namesize */
+		namesize,		/* namesize */
 		0);			/* chksum */
-	push_hdr(s);
-	push_rest(name);
+	offset += len;
+
+	if (len != CPIO_HDR_LEN ||
+	    push_rest(name, namesize) < 0)
+		return -1;
+
 	return 0;
 }
 
@@ -187,7 +221,7 @@ struct generic_type {
 	mode_t mode;
 };
 
-static struct generic_type generic_type_table[] = {
+static const struct generic_type generic_type_table[] = {
 	[GT_DIR] = {
 		.type = "dir",
 		.mode = S_IFDIR
@@ -240,7 +274,8 @@ static int cpio_mknod(const char *name, unsigned int mode,
 		       uid_t uid, gid_t gid, char dev_type,
 		       unsigned int maj, unsigned int min)
 {
-	char s[256];
+	int len;
+	unsigned int namesize;
 
 	if (dev_type == 'b')
 		mode |= S_IFBLK;
@@ -249,9 +284,11 @@ static int cpio_mknod(const char *name, unsigned int mode,
 
 	if (name[0] == '/')
 		name++;
-	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
+	namesize = strlen(name) + 1;
+
+	len = dprintf(outfd, "%s%08X%08X%08lX%08lX%08X%08lX"
 	       "%08X%08X%08X%08X%08X%08X%08X",
-		"070701",		/* magic */
+		do_csum ? "070702" : "070701", /* magic */
 		ino++,			/* ino */
 		mode,			/* mode */
 		(long) uid,		/* uid */
@@ -263,10 +300,14 @@ static int cpio_mknod(const char *name, unsigned int mode,
 		1,			/* minor */
 		maj,			/* rmajor */
 		min,			/* rminor */
-		(unsigned)strlen(name) + 1,/* namesize */
+		namesize,		/* namesize */
 		0);			/* chksum */
-	push_hdr(s);
-	push_rest(name);
+	offset += len;
+
+	if (len != CPIO_HDR_LEN ||
+	    push_rest(name, namesize) < 0)
+		return -1;
+
 	return 0;
 }
 
@@ -291,19 +332,42 @@ static int cpio_mknod_line(const char *line)
 	return rc;
 }
 
+static int cpio_mkfile_csum(int fd, unsigned long size, uint32_t *csum)
+{
+	while (size) {
+		unsigned char filebuf[65536];
+		ssize_t this_read;
+		size_t i, this_size = MIN(size, sizeof(filebuf));
+
+		this_read = read(fd, filebuf, this_size);
+		if (this_read <= 0 || this_read > this_size)
+			return -1;
+
+		for (i = 0; i < this_read; i++)
+			*csum += filebuf[i];
+
+		size -= this_read;
+	}
+	/* seek back to the start for data segment I/O */
+	if (lseek(fd, 0, SEEK_SET) < 0)
+		return -1;
+
+	return 0;
+}
+
 static int cpio_mkfile(const char *name, const char *location,
 			unsigned int mode, uid_t uid, gid_t gid,
 			unsigned int nlinks)
 {
-	char s[256];
-	char *filebuf = NULL;
 	struct stat buf;
-	long size;
-	int file = -1;
-	int retval;
+	unsigned long size;
+	int file, retval, len;
 	int rc = -1;
-	int namesize;
+	time_t mtime;
+	int namesize, namepadlen;
 	unsigned int i;
+	uint32_t csum = 0;
+	ssize_t this_read;
 
 	mode |= S_IFREG;
 
@@ -319,87 +383,133 @@ static int cpio_mkfile(const char *name, const char *location,
 		goto error;
 	}
 
-	filebuf = malloc(buf.st_size);
-	if (!filebuf) {
-		fprintf (stderr, "out of memory\n");
+	if (do_file_mtime) {
+		mtime = default_mtime;
+	} else {
+		mtime = buf.st_mtime;
+		if (mtime > 0xffffffff) {
+			fprintf(stderr, "%s: Timestamp exceeds maximum cpio timestamp, clipping.\n",
+					location);
+			mtime = 0xffffffff;
+		}
+
+		if (mtime < 0) {
+			fprintf(stderr, "%s: Timestamp negative, clipping.\n",
+					location);
+			mtime = 0;
+		}
+	}
+
+	if (buf.st_size > 0xffffffff) {
+		fprintf(stderr, "%s: Size exceeds maximum cpio file size\n",
+			location);
 		goto error;
 	}
 
-	retval = read (file, filebuf, buf.st_size);
-	if (retval < 0) {
-		fprintf (stderr, "Can not read %s file\n", location);
+	if (do_csum && cpio_mkfile_csum(file, buf.st_size, &csum) < 0) {
+		fprintf(stderr, "Failed to checksum file %s\n", location);
 		goto error;
 	}
 
 	size = 0;
+	namepadlen = 0;
 	for (i = 1; i <= nlinks; i++) {
-		/* data goes on last link */
-		if (i == nlinks) size = buf.st_size;
-
 		if (name[0] == '/')
 			name++;
 		namesize = strlen(name) + 1;
-		sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
+
+		/* data goes on last link, after any alignment padding */
+		if (i == nlinks)
+			size = buf.st_size;
+
+		if (dalign && size > dalign) {
+			namepadlen = padlen(offset + CPIO_HDR_LEN + namesize,
+					    dalign);
+			if (namesize + namepadlen > PATH_MAX) {
+				fprintf(stderr,
+					"%s: best-effort alignment %u missed\n",
+					name, dalign);
+				namepadlen = 0;
+			}
+		}
+
+		len = dprintf(outfd, "%s%08X%08X%08lX%08lX%08X%08lX"
 		       "%08lX%08X%08X%08X%08X%08X%08X",
-			"070701",		/* magic */
+			do_csum ? "070702" : "070701", /* magic */
 			ino,			/* ino */
 			mode,			/* mode */
 			(long) uid,		/* uid */
 			(long) gid,		/* gid */
 			nlinks,			/* nlink */
-			(long) buf.st_mtime,	/* mtime */
+			(long) mtime,		/* mtime */
 			size,			/* filesize */
 			3,			/* major */
 			1,			/* minor */
 			0,			/* rmajor */
 			0,			/* rminor */
-			namesize,		/* namesize */
-			0);			/* chksum */
-		push_hdr(s);
-		push_string(name);
-		push_pad();
+			namesize + namepadlen,	/* namesize */
+			size ? csum : 0);	/* chksum */
+		offset += len;
+
+		if (len != CPIO_HDR_LEN ||
+		    push_buf(name, namesize) < 0 ||
+		    push_pad(namepadlen ? namepadlen : padlen(offset, 4)) < 0)
+			goto error;
 
 		if (size) {
-			if (fwrite(filebuf, size, 1, stdout) != 1) {
+			this_read = copy_file_range(file, NULL, outfd, NULL, size, 0);
+			if (this_read > 0) {
+				if (this_read > size)
+					goto error;
+				offset += this_read;
+				size -= this_read;
+			}
+			/* short or failed copy falls back to read/write... */
+		}
+
+		while (size) {
+			unsigned char filebuf[65536];
+			size_t this_size = MIN(size, sizeof(filebuf));
+
+			this_read = read(file, filebuf, this_size);
+			if (this_read <= 0 || this_read > this_size) {
+				fprintf(stderr, "Can not read %s file\n", location);
+				goto error;
+			}
+
+			if (write(outfd, filebuf, this_read) != this_read) {
 				fprintf(stderr, "writing filebuf failed\n");
 				goto error;
 			}
-			offset += size;
-			push_pad();
+			offset += this_read;
+			size -= this_read;
 		}
+		if (push_pad(padlen(offset, 4)) < 0)
+			goto error;
 
 		name += namesize;
 	}
 	ino++;
 	rc = 0;
-	
+
 error:
-	if (filebuf) free(filebuf);
-	if (file >= 0) close(file);
+	if (file >= 0)
+		close(file);
 	return rc;
 }
 
 static char *cpio_replace_env(char *new_location)
 {
 	char expanded[PATH_MAX + 1];
-	char env_var[PATH_MAX + 1];
-	char *start;
-	char *end;
-
-	for (start = NULL; (start = strstr(new_location, "${")); ) {
-		end = strchr(start, '}');
-		if (start < end) {
-			*env_var = *expanded = '\0';
-			strncat(env_var, start + 2, end - start - 2);
-			strncat(expanded, new_location, start - new_location);
-			strncat(expanded, getenv(env_var),
-				PATH_MAX - strlen(expanded));
-			strncat(expanded, end + 1,
-				PATH_MAX - strlen(expanded));
-			strncpy(new_location, expanded, PATH_MAX);
-			new_location[PATH_MAX] = 0;
-		} else
-			break;
+	char *start, *end, *var;
+
+	while ((start = strstr(new_location, "${")) &&
+	       (end = strchr(start + 2, '}'))) {
+		*start = *end = 0;
+		var = getenv(start + 2);
+		snprintf(expanded, sizeof expanded, "%s%s%s",
+			 new_location, var ? var : "", end + 1);
+		strcpy(new_location, expanded);
 	}
 
 	return new_location;
@@ -460,7 +570,7 @@ static int cpio_mkfile_line(const char *line)
 static void usage(const char *prog)
 {
 	fprintf(stderr, "Usage:\n"
-		"\t%s [-t <timestamp>] <cpio_list>\n"
+		"\t%s [-t <timestamp>] [-c] [-o <output_file>] [-a <data_align>] <cpio_list>\n"
 		"\n"
 		"<cpio_list> is a file containing newline separated entries that\n"
 		"describe the files to be included in the initramfs archive:\n"
@@ -494,12 +604,18 @@ static void usage(const char *prog)
 		"file /sbin/kinit /usr/src/klibc/kinit/kinit 0755 0 0\n"
 		"\n"
 		"<timestamp> is time in seconds since Epoch that will be used\n"
-		"as mtime for symlinks, special files and directories. The default\n"
-		"is to use the current time for these entries.\n",
+		"as mtime for symlinks, directories, regular and special files.\n"
+		"The default is to use the current time for all files, but\n"
+		"preserve modification time for regular files.\n"
+		"-c: calculate and store 32-bit checksums for file data.\n"
+		"<output_file>: write cpio to this file instead of stdout\n"
+		"<data_align>: attempt to align file data by zero-padding the\n"
+		"filename field up to data_align. Must be a multiple of 4.\n"
+		"Alignment is best-effort; PATH_MAX limits filename padding.\n",
 		prog);
 }
 
-struct file_handler file_handler_table[] = {
+static const struct file_handler file_handler_table[] = {
 	{
 		.type    = "file",
 		.handler = cpio_mkfile_line,
@@ -537,7 +653,7 @@ int main (int argc, char *argv[])
 
 	default_mtime = time(NULL);
 	while (1) {
-		int opt = getopt(argc, argv, "t:h");
+		int opt = getopt(argc, argv, "t:cho:a:");
 		char *invalid;
 
 		if (opt == -1)
@@ -551,6 +667,29 @@ int main (int argc, char *argv[])
 				usage(argv[0]);
 				exit(1);
 			}
+			do_file_mtime = true;
+			break;
+		case 'c':
+			do_csum = true;
+			break;
+		case 'o':
+			outfd = open(optarg,
+				     O_WRONLY | O_CREAT | O_LARGEFILE | O_TRUNC,
+				     0600);
+			if (outfd < 0) {
+				fprintf(stderr, "failed to open %s\n", optarg);
+				usage(argv[0]);
+				exit(1);
+			}
+			break;
+		case 'a':
+			dalign = strtoul(optarg, &invalid, 10);
+			if (!*optarg || *invalid || (dalign & 3)) {
+				fprintf(stderr, "Invalid data_align: %s\n",
+						optarg);
+				usage(argv[0]);
+				exit(1);
+			}
 			break;
 		case 'h':
 		case '?':
@@ -559,6 +698,16 @@ int main (int argc, char *argv[])
 		}
 	}
 
+	/*
+	 * Timestamps after 2106-02-07 06:28:15 UTC have an ascii hex time_t
+	 * representation that exceeds 8 chars and breaks the cpio header
+	 * specification. Negative timestamps similarly exceed 8 chars.
+	 */
+	if (default_mtime > 0xffffffff || default_mtime < 0) {
+		fprintf(stderr, "ERROR: Timestamp out of range for cpio format\n");
+		exit(1);
+	}
+
 	if (argc - optind != 1) {
 		usage(argv[0]);
 		exit(1);
@@ -626,7 +775,7 @@ int main (int argc, char *argv[])
 		}
 	}
 	if (ec == 0)
-		cpio_trailer();
+		ec = cpio_trailer();
 
 	exit(ec);
 }