Resurrect the no-mtools installersyslinux-2.04-pre1

3 files changed, 499 insertions, 2 deletions

diff --git a/Makefile b/Makefile
index e6797fa4..5494a6d1 100644
--- a/Makefile
+++ b/Makefile
@@ -41,13 +41,14 @@ VERSION  = $(shell cat version)
 # like to keep those uniform for debugging reasons; however, distributors 
 # want to recompile the installers (ITARGET).
 #
-CSRC    = syslinux.c syslxmod.c gethostip.c
+CSRC    = syslinux.c syslinux-nomtools.c syslxmod.c gethostip.c
 NASMSRC  = ldlinux.asm syslinux.asm copybs.asm \
 	  pxelinux.asm mbr.asm isolinux.asm isolinux-debug.asm
 SOURCES = $(CSRC) *.h $(NASMSRC) *.inc
 BTARGET = kwdhash.gen version.gen ldlinux.bss ldlinux.sys ldlinux.bin \
 	  pxelinux.0 mbr.bin isolinux.bin isolinux-debug.bin libsyslinux.a
-ITARGET = syslinux.com syslinux copybs.com gethostip mkdiskimage
+ITARGET = syslinux.com syslinux syslinux-nomtools copybs.com gethostip \
+	  mkdiskimage
 DOCS    = COPYING NEWS README TODO *.doc sample com32
 OTHER   = Makefile bin2c.pl now.pl genhash.pl keywords findpatch.pl \
 	  keytab-lilo.pl version version.pl sys2ansi.pl \
@@ -147,6 +148,9 @@ libsyslinux.a: bootsect_bin.o ldlinux_bin.o syslxmod.o
 syslinux: syslinux.o libsyslinux.a
 	$(CC) $(LDFLAGS) -o $@ $^
 
+syslinux-nomtools: syslinux-nomtools.o libsyslinux.a
+	$(CC) $(LDFLAGS) -o $@ $^
+
 syslxmod.o: syslxmod.c patch.offset
 	$(CC) $(INCLUDE) $(CFLAGS) -DPATCH_OFFSET=`cat patch.offset` \
 		-c -o $@ $<
diff --git a/NEWS b/NEWS
index 1c208403..6067bccc 100644
--- a/NEWS
+++ b/NEWS
@@ -9,6 +9,9 @@ Changes in 2.04:
 	  derivatives...
 	* PXELINUX: Attempt to negotiate full Ethernet-sized blocks
 	  (1468 bytes) using the blksize option.
+	* SYSLINUX: Resurrect the old no-mtools version of the
+	  installer, although as a root-only tool.  Some distributors
+	  have indicated that they need a small standalone installer.
 
 Changes in 2.03:
 	* Actually support comment lines in the configuration file.
diff --git a/syslinux-nomtools.c b/syslinux-nomtools.c
new file mode 100644
index 00000000..9e838358
--- /dev/null
+++ b/syslinux-nomtools.c
@@ -0,0 +1,490 @@
+#ident "$Id$"
+/* ----------------------------------------------------------------------- *
+ *   
+ *   Copyright 1998-2003 H. Peter Anvin - All Rights Reserved
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation, Inc., 675 Mass Ave, Cambridge MA 02139,
+ *   USA; either version 2 of the License, or (at your option) any later
+ *   version; incorporated herein by reference.
+ *
+ * ----------------------------------------------------------------------- */
+
+/*
+ * syslinux.c - Linux installer program for SYSLINUX
+ *
+ * This program ought to be portable.  I hope so, at least.
+ *
+ * This is an alternate version of the installer which doesn't require
+ * mtools, but requires root privilege.
+ */
+
+#define _XOPEN_SOURCE 500	/* Required on glibc 2.x */
+#define _BSD_SOURCE
+#include <alloca.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <mntent.h>
+#include <paths.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include "syslinux.h"
+
+#ifndef _PATH_MOUNT
+#define _PATH_MOUNT "/bin/mount"
+#endif
+
+#ifndef _PATH_UMOUNT
+#define _PATH_UMOUNT "/bin/umount"
+#endif
+
+char *program;			/* Name of program */
+char *device;			/* Device to install to */
+uid_t ruid;			/* Real uid */
+uid_t euid;			/* Initial euid */
+pid_t mypid;
+
+enum bs_offsets {
+  bsJump          = 0x00,
+  bsOemName       = 0x03,
+  bsBytesPerSec   = 0x0b,
+  bsSecPerClust   = 0x0d,
+  bsResSectors    = 0x0e,
+  bsFATs          = 0x10,
+  bsRootDirEnts   = 0x11,
+  bsSectors       = 0x13,
+  bsMedia         = 0x15,
+  bsFATsecs       = 0x16,
+  bsSecPerTrack   = 0x18,
+  bsHeads         = 0x1a,
+  bsHiddenSecs    = 0x1c,
+  bsHugeSectors   = 0x20,
+  bsDriveNumber   = 0x24,
+  bsReserved1     = 0x25,
+  bsBootSignature = 0x26,
+  bsVolumeID      = 0x27,
+  bsVolumeLabel   = 0x2b,
+  bsFileSysType   = 0x36,
+  bsCode          = 0x3e,
+  bsSignature     = 0x1fe
+};
+
+/*
+ * Access functions for littleendian numbers, possibly misaligned.
+ */
+static u_int16_t get_16(unsigned char *p)
+{
+  return (u_int16_t)p[0] + ((u_int16_t)p[1] << 8);
+}
+
+static u_int32_t get_32(unsigned char *p)
+{
+  return (u_int32_t)p[0] + ((u_int32_t)p[1] << 8) +
+    ((u_int32_t)p[2] << 16) + ((u_int32_t)p[3] << 24);
+}
+
+#if 0				/* Not needed */
+static void set_16(unsigned char *p, u_int16_t v)
+{
+  p[0] = (v & 0xff);
+  p[1] = ((v >> 8) & 0xff);
+}
+
+static void set_32(unsigned char *p, u_int32_t v)
+{
+  p[0] = (v & 0xff);
+  p[1] = ((v >> 8) & 0xff);
+  p[2] = ((v >> 16) & 0xff);
+  p[3] = ((v >> 24) & 0xff);
+}
+#endif
+
+void usage(void)
+{
+  fprintf(stderr, "Usage: %s [-sf] [-o offset] device\n", program);
+  exit(1);
+}
+
+/*
+ * read/write wrapper functions
+ */
+ssize_t xpread(int fd, void *buf, size_t count, off_t offset)
+{
+  ssize_t rv;
+  ssize_t done = 0;
+
+  while ( count ) {
+    rv = pread(fd, buf, count, offset);
+    if ( rv == 0 ) {
+      fprintf(stderr, "%s: short read\n", program);
+      exit(1);
+    } else if ( rv == -1 ) {
+      if ( errno == EINTR ) {
+	continue;
+      } else {
+	perror(program);
+	exit(1);
+      }
+    } else {
+      offset += rv;
+      done += rv;
+      count -= rv;
+    }
+  }
+
+  return done;
+}
+
+ssize_t xpwrite(int fd, void *buf, size_t count, off_t offset)
+{
+  ssize_t rv;
+  ssize_t done = 0;
+
+  while ( count ) {
+    rv = pwrite(fd, buf, count, offset);
+    if ( rv == 0 ) {
+      fprintf(stderr, "%s: short write\n", program);
+      exit(1);
+    } else if ( rv == -1 ) {
+      if ( errno == EINTR ) {
+	continue;
+      } else {
+	perror(program);
+	exit(1);
+      }
+    } else {
+      offset += rv;
+      done += rv;
+      count -= rv;
+    }
+  }
+
+  return done;
+}
+
+int main(int argc, char *argv[])
+{
+  static unsigned char sectbuf[512];
+  unsigned char *dp;
+  const unsigned char *cdp;
+  int dev_fd, fd;
+  struct stat st;
+  int nb, left, veryold;
+  unsigned int sectors, clusters;
+  int err = 0;
+  pid_t f, w;
+  int status;
+  char *mntpath = NULL, mntname[64], devfdname[64];
+  char *ldlinux_name, **argp, *opt;
+  int my_umask;
+  int force = 0;		/* -f (force) option */
+  off_t offset = 0;		/* -o (offset) option */
+
+  ruid = getuid();
+  euid = geteuid();
+  mypid = getpid();
+  
+  if ( !euid )
+    setreuid(-1, ruid);		/* Run as regular user until we need it */
+
+  program = argv[0];
+  
+  device = NULL;
+
+  for ( argp = argv+1 ; *argp ; argp++ ) {
+    if ( **argp == '-' ) {
+      opt = *argp + 1;
+      if ( !*opt )
+	usage();
+
+      while ( *opt ) {
+	if ( *opt == 's' ) {
+	  syslinux_make_stupid();	/* Use "safe, slow and stupid" code */
+	} else if ( *opt == 'f' ) {
+	  force = 1;		/* Force install */
+	} else if ( *opt == 'o' && argp[1] ) {
+	  offset = strtoul(*++argp, NULL, 0); /* Byte offset */
+	} else {
+	  usage();
+	}
+	opt++;
+      }
+    } else {
+      if ( device )
+	usage();
+      device = *argp;
+    }
+  }
+
+  if ( !device )
+    usage();
+
+  /*
+   * First make sure we can open the device at all, and that we have
+   * read/write permission.
+   */
+  dev_fd = open(device, O_RDWR);
+  if ( dev_fd < 0 || fstat(dev_fd, &st) < 0 ) {
+    perror(device);
+    exit(1);
+  }
+
+  if ( !force && !S_ISBLK(st.st_mode) && !S_ISREG(st.st_mode) ) {
+    fprintf(stderr, "%s: not a block device or regular file (use -f to override)\n", device);
+    exit(1);
+  }
+
+  if ( !force && offset != 0 && !S_ISREG(st.st_mode) ) {
+    fprintf(stderr, "%s: not a regular file and an offset specified (use -f to override)\n", device);
+    exit(1);
+  }
+
+  if ( lseek(dev_fd, offset, SEEK_SET) != offset ) {
+    if ( !(force && errno == EBADF) ) {
+      fprintf(stderr, "%s: seek error", device);
+      exit(1);
+    }
+  }
+
+  xpread(dev_fd, sectbuf, 512, offset);
+  fsync(dev_fd);
+  
+  /*
+   * Check to see that what we got was indeed an MS-DOS boot sector/superblock
+   */
+
+  if ( sectbuf[bsBootSignature] == 0x29 ) {
+    /* It's DOS, and it has all the new nice fields */
+
+    veryold = 0;
+
+    sectors = get_16(sectbuf+bsSectors);
+    sectors = sectors ? sectors : get_32(sectbuf+bsHugeSectors);
+    clusters = sectors / sectbuf[bsSecPerClust];
+
+    if ( !memcmp(sectbuf+bsFileSysType, "FAT12   ", 8) ) {
+      if ( clusters > 4086 ) {
+	fprintf(stderr, "%s: ERROR: FAT12 but claims more than 4086 clusters\n",
+		device);
+	exit(1);
+      }
+    } else if ( !memcmp(sectbuf+bsFileSysType, "FAT16   ", 8) ) {
+      if ( clusters <= 4086 ) {
+	fprintf(stderr, "%s: ERROR: FAT16 but claims less than 4086 clusters\n",
+		device);
+	exit(1);
+      }
+    } else if ( !memcmp(sectbuf+bsFileSysType, "FAT     ", 8) ) {
+      /* OS/2 sets up the filesystem as just `FAT'. */
+    } else {
+      fprintf(stderr, "%s: filesystem type \"%8.8s\" not supported\n",
+	      device, sectbuf+bsFileSysType);
+      exit(1);
+    }
+  } else {
+    veryold = 1;
+
+    if ( sectbuf[bsSecPerClust] & (sectbuf[bsSecPerClust] - 1) ||
+	 sectbuf[bsSecPerClust] == 0 ) {
+      fprintf(stderr, "%s: This doesn't look like a FAT filesystem\n",
+	      device);
+    }
+
+    sectors = get_16(sectbuf+bsSectors);
+    sectors = sectors ? sectors : get_32(sectbuf+bsHugeSectors);
+    clusters = sectors / sectbuf[bsSecPerClust];
+  }
+
+  if ( get_16(sectbuf+bsBytesPerSec) != 512 ) {
+    fprintf(stderr, "%s: Sector sizes other than 512 not supported\n",
+	    device);
+    exit(1);
+  }
+  if ( sectbuf[bsSecPerClust] > 32 ) {
+    fprintf(stderr, "%s: Cluster sizes larger than 16K not supported\n",
+	    device);
+  }
+
+  /*
+   * Now mount the device.
+   */
+  if ( euid ) {
+    fprintf(stderr, "%s: This program needs root privilege\n", program);
+    exit(1);
+  } else {
+    int i = 0;
+    struct stat dst;
+    int rv;
+
+    /* We're root or at least setuid.
+       Make a temp dir and pass all the gunky options to mount. */
+
+    if ( chdir("/tmp") ) {
+      perror(program);
+      exit(1);
+    }
+
+#define TMP_MODE (S_IXUSR|S_IWUSR|S_IXGRP|S_IWGRP|S_IWOTH|S_IXOTH|S_ISVTX)
+
+    if ( stat(".", &dst) || !S_ISDIR(dst.st_mode) ||
+	 (dst.st_mode & TMP_MODE) != TMP_MODE ) {
+      fprintf(stderr, "%s: possibly unsafe /tmp permissions\n", program);
+      exit(1);
+    }
+
+    for ( i = 0 ; ; i++ ) {
+      snprintf(mntname, sizeof mntname, "syslinux.mnt.%lu.%d",
+	       (unsigned long)mypid, i);
+
+      if ( lstat(mntname, &dst) != -1 || errno != ENOENT )
+	continue;
+
+      seteuid(0);		/* *** BECOME ROOT *** */
+      rv = mkdir(mntname, 0000); /* AS ROOT */
+      seteuid(ruid);
+
+      if ( rv == -1 ) {
+	if ( errno == EEXIST || errno == EINTR )
+	  continue;
+	perror(program);
+	exit(1);
+      }
+
+      if ( lstat(mntname, &dst) || dst.st_mode != (S_IFDIR|0000) ||
+	   dst.st_uid != 0 ) {
+	fprintf(stderr, "%s: someone is trying to symlink race us!\n", program);
+	exit(1);
+      }
+      break;			/* OK, got something... */
+    }
+
+    mntpath = mntname;
+
+    snprintf(devfdname, sizeof devfdname, "/proc/%lu/fd/%d",
+	     (unsigned long)mypid, dev_fd);
+
+    f = fork();
+    if ( f < 0 ) {
+      perror(program);
+      rmdir(mntpath);
+      exit(1);
+    } else if ( f == 0 ) {
+      char mnt_opts[128];
+      seteuid(0);		/* ***BECOME ROOT*** */
+      setuid(0);
+      if ( S_ISREG(st.st_mode) ) {
+	snprintf(mnt_opts, sizeof mnt_opts, "rw,nodev,noexec,loop,offset=%llu,umask=077,uid=%lu",
+		 (unsigned long long)offset, (unsigned long)ruid);
+      } else {
+	snprintf(mnt_opts, sizeof mnt_opts, "rw,nodev,noexec,umask=077,uid=%lu",
+		 (unsigned long)ruid);
+      }
+      execl(_PATH_MOUNT, _PATH_MOUNT, "-t", "msdos", "-o", mnt_opts,\
+	    devfdname, mntpath, NULL);
+      _exit(255);		/* execl failed */
+    }
+  }
+
+  w = waitpid(f, &status, 0);
+  if ( w != f || status ) {
+    if ( !euid )
+      rmdir(mntpath);
+    exit(1);			/* Mount failed */
+  }
+
+  ldlinux_name = alloca(strlen(mntpath)+13);
+  if ( !ldlinux_name ) {
+    perror(program);
+    err = 1;
+    goto umount;
+  }
+  sprintf(ldlinux_name, "%s/ldlinux.sys", mntpath);
+
+  unlink(ldlinux_name);
+  fd = open(ldlinux_name, O_WRONLY|O_CREAT|O_TRUNC, 0444);
+  if ( fd < 0 ) {
+    perror(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;
+  }
+
+  /*
+   * I don't understand why I need this.  Does the DOS filesystems
+   * not honour the mode passed to open()?
+   */
+  my_umask = umask(0777);
+  umask(my_umask);
+  fchmod(fd, 0444 & ~my_umask);
+
+  close(fd);
+
+umount:
+  f = fork();
+  if ( f < 0 ) {
+    perror("fork");
+    exit(1);
+  } else if ( f == 0 ) {
+    seteuid(0);		/* ***BECOME ROOT*** */
+    setuid(0);
+    execl(_PATH_UMOUNT, _PATH_UMOUNT, mntpath, NULL);
+  }
+
+  w = waitpid(f, &status, 0);
+  if ( w != f || status ) {
+    exit(1);
+  }
+
+  sync();
+
+  if ( !euid ) {
+    seteuid(0);			/* *** BECOME ROOT *** */
+    rmdir(mntpath);		/* AS ROOT */
+    seteuid(ruid);
+  }
+
+  if ( err )
+    exit(err);
+
+  /*
+   * To finish up, write the boot sector
+   */
+
+  /* Read the superblock again since it might have changed while mounted */
+  xpread(dev_fd, sectbuf, 512, offset);
+
+  /* Copy the syslinux code into the boot sector */
+  syslinux_make_bootsect(sectbuf);
+
+  /* Write new boot sector */
+  xpwrite(dev_fd, sectbuf, 512, offset);
+
+  close(dev_fd);
+  sync();
+
+  /* Done! */
+
+  return 0;
+}