exec: remove support for transparently ungziping executables

Remove support for transparently ungziping executables from the exec
server. The code in question makes the exec server unnecessarily
complex and since the exec server is an essential process, crashing it
makes /hurd/init crash the whole system.

Since the gzip code is not thread-safe, all access to it is
serialized, so there is a trivial way for one user to delay another
users gzipped executables for some unspecified time.

This can be accomplished by padding any program with easily compressed
data, zipping it and executing it. Using such a program as an passive
translator and then triggering its execution by the filesystem
translator also stalls any requests to that filesystem (observed using
the libdiskfs-based ext2fs).

Since compressed executables cannot be mapped into the memory, they
have to be uncompressed into allocated memory first. This is slower
and any user with access to the exec server can make it allocate
arbitrary amounts of memory. If the Hurd had proper memory accounting,
this would probably be a way around it.

So the compression support in exec seemingly creates various issues
for little value, at least with the abundance of nonvolatile memory
available today.

* exec/Makefile: Remove gzip related files.
* exec/exec.c: Remove anything #ifdef GZIPped.
* exec/unzip.c: Move to libstore.
* exec/crypt.h: Likewise.
* exec/gzip.h: Likewise.
* exec/inflate.c: Likewise.
* exec/tailor.h: Likewise.
* exec/util.c: Likewise.
* libstore/Makefile: Remove the vpath magic for looking up the zip
  stuff.

1 files changed, 315 insertions, 0 deletions

diff --git a/libstore/gzip.h b/libstore/gzip.h
new file mode 100644
index 00000000..aedc257d
--- /dev/null
+++ b/libstore/gzip.h
@@ -0,0 +1,315 @@
+/* gzip.h -- common declarations for all gzip modules
+ * Copyright (C) 1992-1993, 1996 Jean-loup Gailly.
+ * This is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License, see the file COPYING.
+ */
+
+#if defined(__STDC__) || defined(PROTO)
+#  define OF(args)  args
+#else
+#  define OF(args)  ()
+#endif
+
+#ifdef __STDC__
+   typedef void *voidp;
+#else
+   typedef char *voidp;
+#endif
+
+/* I don't like nested includes, but the string and io functions are used
+ * too often
+ */
+#include <stdio.h>
+#if !defined(NO_STRING_H) || defined(STDC_HEADERS)
+#  include <string.h>
+#  if !defined(STDC_HEADERS) && !defined(NO_MEMORY_H) && !defined(__GNUC__)
+#    include <memory.h>
+#  endif
+#  define memzero(s, n)     memset ((voidp)(s), 0, (n))
+#else
+#  include <strings.h>
+#  define strchr            index 
+#  define strrchr           rindex
+#  define memcpy(d, s, n)   bcopy((s), (d), (n)) 
+#  define memcmp(s1, s2, n) bcmp((s1), (s2), (n)) 
+#  define memzero(s, n)     bzero((s), (n))
+#endif
+
+#ifndef RETSIGTYPE
+#  define RETSIGTYPE void
+#endif
+
+#define local static
+
+typedef unsigned char  uch;
+typedef unsigned short ush;
+typedef unsigned long  ulg;
+
+/* Return codes from gzip */
+#define OK      0
+#define ERROR   1
+#define WARNING 2
+
+/* Compression methods (see algorithm.doc) */
+#define STORED      0
+#define COMPRESSED  1
+#define PACKED      2
+#define LZHED       3
+/* methods 4 to 7 reserved */
+#define DEFLATED    8
+#define MAX_METHODS 9
+extern int method;         /* compression method */
+
+/* To save memory for 16 bit systems, some arrays are overlaid between
+ * the various modules:
+ * deflate:  prev+head   window      d_buf  l_buf  outbuf
+ * unlzw:    tab_prefix  tab_suffix  stack  inbuf  outbuf
+ * inflate:              window             inbuf
+ * unpack:               window             inbuf  prefix_len
+ * unlzh:    left+right  window      c_table inbuf c_len
+ * For compression, input is done in window[]. For decompression, output
+ * is done in window except for unlzw.
+ */
+
+#ifndef	INBUFSIZ
+#  ifdef SMALL_MEM
+#    define INBUFSIZ  0x2000  /* input buffer size */
+#  else
+#    define INBUFSIZ  0x8000  /* input buffer size */
+#  endif
+#endif
+#define INBUF_EXTRA  64     /* required by unlzw() */
+
+#ifndef	OUTBUFSIZ
+#  ifdef SMALL_MEM
+#    define OUTBUFSIZ   8192  /* output buffer size */
+#  else
+#    define OUTBUFSIZ  16384  /* output buffer size */
+#  endif
+#endif
+#define OUTBUF_EXTRA 2048   /* required by unlzw() */
+
+#ifndef DIST_BUFSIZE
+#  ifdef SMALL_MEM
+#    define DIST_BUFSIZE 0x2000 /* buffer for distances, see trees.c */
+#  else
+#    define DIST_BUFSIZE 0x8000 /* buffer for distances, see trees.c */
+#  endif
+#endif
+
+#ifdef DYN_ALLOC
+#  define EXTERN(type, array)  extern type * near array
+#  define DECLARE(type, array, size)  type * near array
+#  define ALLOC(type, array, size) { \
+      array = (type*)fcalloc((size_t)(((size)+1L)/2), 2*sizeof(type)); \
+      if (array == NULL) error("insufficient memory"); \
+   }
+#  define FREE(array) {if (array != NULL) fcfree(array), array=NULL;}
+#else
+#  define EXTERN(type, array)  extern type array[]
+#  define DECLARE(type, array, size)  type array[size]
+#  define ALLOC(type, array, size)
+#  define FREE(array)
+#endif
+
+EXTERN(uch, inbuf);          /* input buffer */
+EXTERN(uch, outbuf);         /* output buffer */
+EXTERN(ush, d_buf);          /* buffer for distances, see trees.c */
+EXTERN(uch, window);         /* Sliding window and suffix table (unlzw) */
+#define tab_suffix window
+#ifndef MAXSEG_64K
+#  define tab_prefix prev    /* hash link (see deflate.c) */
+#  define head (prev+WSIZE)  /* hash head (see deflate.c) */
+   EXTERN(ush, tab_prefix);  /* prefix code (see unlzw.c) */
+#else
+#  define tab_prefix0 prev
+#  define head tab_prefix1
+   EXTERN(ush, tab_prefix0); /* prefix for even codes */
+   EXTERN(ush, tab_prefix1); /* prefix for odd  codes */
+#endif
+
+extern unsigned insize; /* valid bytes in inbuf */
+extern unsigned inptr;  /* index of next byte to be processed in inbuf */
+extern unsigned outcnt; /* bytes in output buffer */
+
+extern long bytes_in;   /* number of input bytes */
+extern long bytes_out;  /* number of output bytes */
+extern long header_bytes;/* number of bytes in gzip header */
+
+#define isize bytes_in
+/* for compatibility with old zip sources (to be cleaned) */
+
+extern int  ifd;        /* input file descriptor */
+extern int  ofd;        /* output file descriptor */
+extern char ifname[];   /* input file name or "stdin" */
+extern char ofname[];   /* output file name or "stdout" */
+extern char *progname;  /* program name */
+
+extern long time_stamp; /* original time stamp (modification time) */
+extern long ifile_size; /* input file size, -1 for devices (debug only) */
+
+typedef int file_t;     /* Do not use stdio */
+#define NO_FILE  (-1)   /* in memory compression */
+
+
+#define	PACK_MAGIC     "\037\036" /* Magic header for packed files */
+#define	GZIP_MAGIC     "\037\213" /* Magic header for gzip files, 1F 8B */
+#define	OLD_GZIP_MAGIC "\037\236" /* Magic header for gzip 0.5 = freeze 1.x */
+#define	LZH_MAGIC      "\037\240" /* Magic header for SCO LZH Compress files*/
+#define PKZIP_MAGIC    "\120\113\003\004" /* Magic header for pkzip files */
+
+/* gzip flag byte */
+#define ASCII_FLAG   0x01 /* bit 0 set: file probably ascii text */
+#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
+#define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
+#define ORIG_NAME    0x08 /* bit 3 set: original file name present */
+#define COMMENT      0x10 /* bit 4 set: file comment present */
+#define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
+#define RESERVED     0xC0 /* bit 6,7:   reserved */
+
+/* internal file attribute */
+#define UNKNOWN 0xffff
+#define BINARY  0
+#define ASCII   1
+
+#ifndef WSIZE
+#  define WSIZE 0x8000     /* window size--must be a power of two, and */
+#endif                     /*  at least 32K for zip's deflate method */
+
+#define MIN_MATCH  3
+#define MAX_MATCH  258
+/* The minimum and maximum match lengths */
+
+#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
+/* Minimum amount of lookahead, except at the end of the input file.
+ * See deflate.c for comments about the MIN_MATCH+1.
+ */
+
+#define MAX_DIST  (WSIZE-MIN_LOOKAHEAD)
+/* In order to simplify the code, particularly on 16 bit machines, match
+ * distances are limited to MAX_DIST instead of WSIZE.
+ */
+
+extern int decrypt;        /* flag to turn on decryption */
+extern int exit_code;      /* program exit code */
+extern int verbose;        /* be verbose (-v) */
+extern int quiet;          /* be quiet (-q) */
+extern int level;          /* compression level */
+extern int test;           /* check .z file integrity */
+extern int to_stdout;      /* output to stdout (-c) */
+extern int save_orig_name; /* set if original name must be saved */
+
+#define get_byte()  (inptr < insize ? inbuf[inptr++] : fill_inbuf(0))
+#define try_byte()  (inptr < insize ? inbuf[inptr++] : fill_inbuf(1))
+
+/* put_byte is used for the compressed output, put_ubyte for the
+ * uncompressed output. However unlzw() uses window for its
+ * suffix table instead of its output buffer, so it does not use put_ubyte
+ * (to be cleaned up).
+ */
+#define put_byte(c) {outbuf[outcnt++]=(uch)(c); if (outcnt==OUTBUFSIZ)\
+   flush_outbuf();}
+#define put_ubyte(c) {window[outcnt++]=(uch)(c); if (outcnt==WSIZE)\
+   flush_window();}
+
+/* Output a 16 bit value, lsb first */
+#define put_short(w) \
+{ if (outcnt < OUTBUFSIZ-2) { \
+    outbuf[outcnt++] = (uch) ((w) & 0xff); \
+    outbuf[outcnt++] = (uch) ((ush)(w) >> 8); \
+  } else { \
+    put_byte((uch)((w) & 0xff)); \
+    put_byte((uch)((ush)(w) >> 8)); \
+  } \
+}
+
+/* Output a 32 bit value to the bit stream, lsb first */
+#define put_long(n) { \
+    put_short((n) & 0xffff); \
+    put_short(((ulg)(n)) >> 16); \
+}
+
+#define seekable()    0  /* force sequential output */
+#define translate_eol 0  /* no option -a yet */
+
+#define tolow(c)  (isupper(c) ? (c)-'A'+'a' : (c))    /* force to lower case */
+
+/* Macros for getting two-byte and four-byte header values */
+#define SH(p) ((ush)(uch)((p)[0]) | ((ush)(uch)((p)[1]) << 8))
+#define LG(p) ((ulg)(SH(p)) | ((ulg)(SH((p)+2)) << 16))
+
+/* Diagnostic functions */
+#ifdef DEBUG
+#  define Assert(cond,msg) {if(!(cond)) error(msg);}
+#  define Trace(x) fprintf x
+#  define Tracev(x) {if (verbose) fprintf x ;}
+#  define Tracevv(x) {if (verbose>1) fprintf x ;}
+#  define Tracec(c,x) {if (verbose && (c)) fprintf x ;}
+#  define Tracecv(c,x) {if (verbose>1 && (c)) fprintf x ;}
+#else
+#  define Assert(cond,msg)
+#  define Trace(x)
+#  define Tracev(x)
+#  define Tracevv(x)
+#  define Tracec(c,x)
+#  define Tracecv(c,x)
+#endif
+
+#define WARN(msg) {if (!quiet) fprintf msg ; \
+		   if (exit_code == OK) exit_code = WARNING;}
+
+	/* in zip.c: */
+extern int zip        OF((int in, int out));
+extern int file_read  OF((char *buf,  unsigned size));
+
+	/* in unzip.c */
+extern int unzip      OF((int in, int out));
+extern int check_zipfile OF((int in));
+
+	/* in unpack.c */
+extern int unpack     OF((int in, int out));
+
+	/* in unlzh.c */
+extern int unlzh      OF((int in, int out));
+
+	/* in gzip.c */
+RETSIGTYPE abort_gzip OF((void));
+
+        /* in deflate.c */
+void lm_init OF((int pack_level, ush *flags));
+ulg  deflate OF((void));
+
+        /* in trees.c */
+void ct_init     OF((ush *attr, int *method));
+int  ct_tally    OF((int dist, int lc));
+ulg  flush_block OF((char *buf, ulg stored_len, int eof));
+
+        /* in bits.c */
+void     bi_init    OF((file_t zipfile));
+void     send_bits  OF((int value, int length));
+unsigned bi_reverse OF((unsigned value, int length));
+void     bi_windup  OF((void));
+void     copy_block OF((char *buf, unsigned len, int header));
+extern   int (*read_buf) OF((char *buf, unsigned size));
+
+	/* in util.c: */
+extern int copy           OF((int in, int out));
+extern ulg  updcrc        OF((uch *s, unsigned n));
+extern void clear_bufs    OF((void));
+extern int  fill_inbuf    OF((int eof_ok));
+extern void flush_outbuf  OF((void));
+extern void flush_window  OF((void));
+extern void write_buf     OF((int fd, voidp buf, unsigned cnt));
+extern char *strlwr       OF((char *s));
+/* extern char *basename     OF((char *fname));*/
+extern void make_simple_name OF((char *name));
+extern char *add_envopt   OF((int *argcp, char ***argvp, char *env));
+extern void error         OF((char *m));
+extern void warn          OF((char *a, char *b));
+extern void read_error    OF((void));
+extern void write_error   OF((void));
+extern void display_ratio OF((long num, long den, FILE *file));
+extern voidp xmalloc      OF((unsigned int size));
+
+	/* in inflate.c */
+extern int inflate OF((void));