unify common parts of extlinux and syslinux installer

Thus we can share same command line options and reduce a lot of dup
code...

Seems like a big patch, but the changes are quite safe, no much logical
change.

Signed-off-by: Alek Du <alek.du@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

2 files changed, 114 insertions, 184 deletions

diff --git a/linux/Makefile b/linux/Makefile
index 8872c0fc..9bf56d12 100644
--- a/linux/Makefile
+++ b/linux/Makefile
@@ -23,6 +23,9 @@ CFLAGS	 = $(GCCWARN) -D_FILE_OFFSET_BITS=64 $(OPTFLAGS) $(INCLUDES)
 LDFLAGS	 = -s
 
 SRCS     = syslinux.c \
+	   ../libinstaller/syslxopt.c \
+	   ../libinstaller/syslxcom.c \
+	   ../libinstaller/setadv.c \
            ../libinstaller/syslxmod.c \
 	   ../libinstaller/bootsect_bin.c \
 	   ../libinstaller/ldlinux_bin.c
diff --git a/linux/syslinux.c b/linux/syslinux.c
index 0ac9de92..3032edce 100644
--- a/linux/syslinux.c
+++ b/linux/syslinux.c
@@ -72,22 +72,27 @@
 # include <linux/loop.h>
 #endif
 
-const char *program;		/* Name of program */
-const char *device;		/* Device to install to */
+#include <getopt.h>
+#include <sysexits.h>
+#include "syslxcom.h"
+#include "setadv.h"
+#include "syslxopt.h" /* unified options */
+
+extern const char *program;	/* Name of program */
+
 pid_t mypid;
 char *mntpath = NULL;		/* Path on which to mount */
-off_t filesystem_offset = 0;	/* Filesystem offset */
+
+/*
+ * Image file
+ */
+#define boot_image	syslinux_ldlinux
+#define boot_image_len  syslinux_ldlinux_len
+
 #if DO_DIRECT_MOUNT
 int loop_fd = -1;		/* Loop device */
 #endif
 
-void __attribute__ ((noreturn)) usage(void)
-{
-    fprintf(stderr, "Usage: %s [-sfr][-d directory][-o offset] device\n",
-	    program);
-    exit(1);
-}
-
 void __attribute__ ((noreturn)) die(const char *msg)
 {
     fprintf(stderr, "%s: %s\n", program, msg);
@@ -107,98 +112,6 @@ void __attribute__ ((noreturn)) die(const char *msg)
 }
 
 /*
- * read/write wrapper functions
- */
-ssize_t xpread(int fd, void *buf, size_t count, off_t offset)
-{
-    char *bufp = (char *)buf;
-    ssize_t rv;
-    ssize_t done = 0;
-
-    while (count) {
-	rv = pread(fd, bufp, count, offset);
-	if (rv == 0) {
-	    die("short read");
-	} else if (rv == -1) {
-	    if (errno == EINTR) {
-		continue;
-	    } else {
-		die(strerror(errno));
-	    }
-	} else {
-	    bufp += rv;
-	    offset += rv;
-	    done += rv;
-	    count -= rv;
-	}
-    }
-
-    return done;
-}
-
-ssize_t xpwrite(int fd, const void *buf, size_t count, off_t offset)
-{
-    const char *bufp = (const char *)buf;
-    ssize_t rv;
-    ssize_t done = 0;
-
-    while (count) {
-	rv = pwrite(fd, bufp, count, offset);
-	if (rv == 0) {
-	    die("short write");
-	} else if (rv == -1) {
-	    if (errno == EINTR) {
-		continue;
-	    } else {
-		die(strerror(errno));
-	    }
-	} else {
-	    bufp += rv;
-	    offset += rv;
-	    done += rv;
-	    count -= rv;
-	}
-    }
-
-    return done;
-}
-
-/*
- * Create a block map for ldlinux.sys
- */
-int make_block_map(uint32_t * sectors, int len, int dev_fd, int fd)
-{
-    int nsectors = 0;
-    int blocksize, nblock, block;
-    int i;
-
-    (void)dev_fd;
-
-    if (ioctl(fd, FIGETBSZ, &blocksize) < 0)
-	die("ioctl FIGETBSZ failed");
-
-    blocksize >>= SECTOR_SHIFT;	/* sectors/block */
-
-    nblock = 0;
-    while (len > 0) {
-	block = nblock++;
-	if (ioctl(fd, FIBMAP, &block) < 0)
-	    die("ioctl FIBMAP failed");
-
-	for (i = 0; i < blocksize; i++) {
-	    if (len <= 0)
-		break;
-
-	    *sectors++ = (block * blocksize) + i;
-	    nsectors++;
-	    len -= (1 << SECTOR_SHIFT);
-	}
-    }
-
-    return nsectors;
-}
-
-/*
  * Mount routine
  */
 int do_mount(int dev_fd, int *cookie, const char *mntpath, const char *fstype)
@@ -234,7 +147,7 @@ int do_mount(int dev_fd, int *cookie, const char *mntpath, const char *fstype)
 		}
 
 		if (ioctl(loop_fd, LOOP_GET_STATUS64, &loopinfo) ||
-		    (loopinfo.lo_offset = filesystem_offset,
+		    (loopinfo.lo_offset = opt.offset,
 		     ioctl(loop_fd, LOOP_SET_STATUS64, &loopinfo)))
 		    die("cannot set up loopback device");
 	    }
@@ -265,7 +178,7 @@ int do_mount(int dev_fd, int *cookie, const char *mntpath, const char *fstype)
 	    if (!S_ISBLK(st.st_mode)) {
 		snprintf(mnt_opts, sizeof mnt_opts,
 			 "rw,nodev,noexec,loop,offset=%llu,umask=077,quiet",
-			 (unsigned long long)filesystem_offset);
+			 (unsigned long long)opt.offset);
 	    } else {
 		snprintf(mnt_opts, sizeof mnt_opts,
 			 "rw,nodev,noexec,umask=077,quiet");
@@ -317,79 +230,76 @@ void do_umount(const char *mntpath, int cookie)
 #endif
 }
 
+/*
+ * Make any user-specified ADV modifications
+ */
+int modify_adv(void)
+{
+    int rv = 0;
+
+    if (opt.set_once) {
+	if (syslinux_setadv(ADV_BOOTONCE, strlen(opt.set_once), opt.set_once)) {
+	    fprintf(stderr, "%s: not enough space for boot-once command\n",
+		    program);
+	    rv = -1;
+	}
+    }
+
+    return rv;
+}
+
+/*
+ * Modify the ADV of an existing installation
+ */
+int modify_existing_adv(const char *path)
+{
+    if (opt.reset_adv)
+	syslinux_reset_adv(syslinux_adv);
+    else if (read_adv(path, "ldlinux.sys") < 0)
+	return 1;
+
+    if (modify_adv() < 0)
+	return 1;
+
+    if (write_adv(path, "ldlinux.sys") < 0)
+	return 1;
+
+    return 0;
+}
+
 int main(int argc, char *argv[])
 {
     static unsigned char sectbuf[SECTOR_SIZE];
-    unsigned char *dp;
-    const unsigned char *cdp;
     int dev_fd, fd;
     struct stat st;
-    int nb, left;
     int err = 0;
     char mntname[128];
-    char *ldlinux_name, **argp, *opt;
-    const char *subdir = NULL;
+    char *ldlinux_name;
+    char *ldlinux_path;
+    const char *subdir;
     uint32_t *sectors = NULL;
-    int ldlinux_sectors;
-    int nsectors = 0;
+    int ldlinux_sectors = (boot_image_len + SECTOR_SIZE - 1) >> SECTOR_SHIFT;
     const char *errmsg;
     int mnt_cookie;
     int patch_sectors;
     int i;
 
-    int force = 0;		/* -f (force) option */
-    int stupid = 0;		/* -s (stupid) option */
-    int raid_mode = 0;		/* -r (RAID) option */
-
-    (void)argc;			/* Unused */
-
-    program = argv[0];
     mypid = getpid();
-
-    device = NULL;
-
     umask(077);
+    parse_options(argc, argv, 1);
 
-    for (argp = argv + 1; *argp; argp++) {
-	if (**argp == '-') {
-	    opt = *argp + 1;
-	    if (!*opt)
-		usage();
-
-	    while (*opt) {
-		if (*opt == 's') {
-		    stupid = 1;
-		} else if (*opt == 'r') {
-		    raid_mode = 1;
-		} else if (*opt == 'f') {
-		    force = 1;	/* Force install */
-		} else if (*opt == 'd' && argp[1]) {
-		    subdir = *++argp;
-		} else if (*opt == 'o' && argp[1]) {
-		    /* Byte offset */
-		    filesystem_offset = (off_t) strtoull(*++argp, NULL, 0);
-		} else {
-		    usage();
-		}
-		opt++;
-	    }
-	} else {
-	    if (device)
-		usage();
-	    device = *argp;
-	}
-    }
+    subdir = opt.directory;
 
-    if (!device)
-	usage();
+    if (!opt.device)
+	usage(EX_USAGE, 1);
 
     /*
      * First make sure we can open the device at all, and that we have
      * read/write permission.
      */
-    dev_fd = open(device, O_RDWR);
+    dev_fd = open(opt.device, O_RDWR);
     if (dev_fd < 0 || fstat(dev_fd, &st) < 0) {
-	perror(device);
+	perror(opt.device);
 	exit(1);
     }
 
@@ -397,18 +307,19 @@ int main(int argc, char *argv[])
 	die("not a device or regular file");
     }
 
-    if (filesystem_offset && S_ISBLK(st.st_mode)) {
+    if (opt.offset && S_ISBLK(st.st_mode)) {
 	die("can't combine an offset with a block device");
     }
 
-    xpread(dev_fd, sectbuf, SECTOR_SIZE, filesystem_offset);
+    fs_type = VFAT;
+    xpread(dev_fd, sectbuf, SECTOR_SIZE, opt.offset);
     fsync(dev_fd);
 
     /*
      * Check to see that what we got was indeed an MS-DOS boot sector/superblock
      */
     if ((errmsg = syslinux_check_bootsect(sectbuf))) {
-	fprintf(stderr, "%s: %s\n", device, errmsg);
+	fprintf(stderr, "%s: %s\n", opt.device, errmsg);
 	exit(1);
     }
 
@@ -468,15 +379,37 @@ int main(int argc, char *argv[])
 	die("mount failed");
     }
 
-    ldlinux_name = alloca(strlen(mntpath) + 14 +
-			  (subdir ? strlen(subdir) + 2 : 0));
+    ldlinux_path = alloca(strlen(mntpath) +  (subdir ? strlen(subdir) + 2 : 0));
+    sprintf(ldlinux_path, "%s%s%s",
+	    mntpath, subdir ? "//" : "", subdir ? subdir : "");
+
+    ldlinux_name = alloca(strlen(ldlinux_path) + 14);
     if (!ldlinux_name) {
 	perror(program);
 	err = 1;
 	goto umount;
     }
-    sprintf(ldlinux_name, "%s%s%s//ldlinux.sys",
-	    mntpath, subdir ? "//" : "", subdir ? subdir : "");
+    sprintf(ldlinux_name, "%s//ldlinux.sys", ldlinux_path);
+
+    /* update ADV only ? */
+    if (opt.update_only == -1) {
+	if (opt.reset_adv || opt.set_once) {
+	    modify_existing_adv(ldlinux_path);
+	    do_umount(mntpath, mnt_cookie);
+	    sync();
+	    rmdir(mntpath);
+	    exit(0);
+	} else
+	    usage(EX_USAGE, 0);
+    }
+
+    /* Read a pre-existing ADV, if already installed */
+    if (opt.reset_adv)
+	syslinux_reset_adv(syslinux_adv);
+    else if (read_adv(ldlinux_path, "ldlinux.sys") < 0)
+	syslinux_reset_adv(syslinux_adv);
+    if (modify_adv() < 0)
+	exit(1);
 
     if ((fd = open(ldlinux_name, O_RDONLY)) >= 0) {
 	uint32_t zero_attr = 0;
@@ -487,25 +420,17 @@ int main(int argc, char *argv[])
     unlink(ldlinux_name);
     fd = open(ldlinux_name, O_WRONLY | O_CREAT | O_TRUNC, 0444);
     if (fd < 0) {
-	perror(device);
+	perror(opt.device);
 	err = 1;
 	goto umount;
     }
 
-    cdp = syslinux_ldlinux;
-    left = syslinux_ldlinux_len;
-    while (left) {
-	nb = write(fd, cdp, left);
-	if (nb == -1 && errno == EINTR)
-	    continue;
-	else if (nb <= 0) {
-	    perror(device);
-	    err = 1;
-	    goto umount;
-	}
-
-	dp += nb;
-	left -= nb;
+    /* Write it the first time */
+    if (xpwrite(fd, boot_image, boot_image_len, 0) != (int)boot_image_len ||
+	xpwrite(fd, syslinux_adv, 2 * ADV_SIZE,
+		boot_image_len) != 2 * ADV_SIZE) {
+	fprintf(stderr, "%s: write failure on %s\n", program, ldlinux_name);
+	exit(1);
     }
 
     fsync(fd);
@@ -520,10 +445,12 @@ int main(int argc, char *argv[])
     /*
      * Create a block map.
      */
-    ldlinux_sectors = (syslinux_ldlinux_len + SECTOR_SIZE - 1) >> SECTOR_SHIFT;
+    ldlinux_sectors += 2; /* 2 ADV sectors */
     sectors = calloc(ldlinux_sectors, sizeof *sectors);
-    nsectors = make_block_map(sectors, syslinux_ldlinux_len, dev_fd, fd);
-
+    if (sectmap(fd, sectors, ldlinux_sectors)) {
+	perror("bmap");
+	exit(1);
+    }
     close(fd);
     sync();
 
@@ -538,15 +465,15 @@ umount:
     /*
      * Patch ldlinux.sys and the boot sector
      */
-    i = syslinux_patch(sectors, nsectors, stupid, raid_mode);
+    i = syslinux_patch(sectors, ldlinux_sectors, opt.stupid_mode, opt.raid_mode);
     patch_sectors = (i + SECTOR_SIZE - 1) >> SECTOR_SHIFT;
 
     /*
      * Write the now-patched first sectors of ldlinux.sys
      */
     for (i = 0; i < patch_sectors; i++) {
-	xpwrite(dev_fd, syslinux_ldlinux + i * SECTOR_SIZE, SECTOR_SIZE,
-		filesystem_offset + ((off_t) sectors[i] << SECTOR_SHIFT));
+	xpwrite(dev_fd, boot_image + i * SECTOR_SIZE, SECTOR_SIZE,
+		opt.offset + ((off_t) sectors[i] << SECTOR_SHIFT));
     }
 
     /*
@@ -554,13 +481,13 @@ umount:
      */
 
     /* Read the superblock again since it might have changed while mounted */
-    xpread(dev_fd, sectbuf, SECTOR_SIZE, filesystem_offset);
+    xpread(dev_fd, sectbuf, SECTOR_SIZE, opt.offset);
 
     /* Copy the syslinux code into the boot sector */
     syslinux_make_bootsect(sectbuf);
 
     /* Write new boot sector */
-    xpwrite(dev_fd, sectbuf, SECTOR_SIZE, filesystem_offset);
+    xpwrite(dev_fd, sectbuf, SECTOR_SIZE, opt.offset);
 
     close(dev_fd);
     sync();