Urlader/urlader.c

#ifndef URLADER
# define URLADER "urlader"
#endif
#define URLADER_VERSION "1.0" // a decimal number, not a version string

#define MAX_ARGC 32
#define MAX_ARGS 256

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <time.h>
#include <fcntl.h>

#include "liblzf/lzf_d.c"

#define TAIL_MAGIC "SCHMORPPACK0"

#ifdef _WIN32

  #include <windows.h>
  //#include <winbase.h>
  #include <shlobj.h>
  #include <shlwapi.h>
  #include <wininet.h>

  static DWORD dword;

  #define u_handle HANDLE
  #define u_invalid_handle 0
  #define u_valid(handle) (!!handle)

  #define u_setenv(name,value) SetEnvironmentVariable (name, value)
  #define u_mkdir(path) !CreateDirectory (path, NULL)
  #define u_chdir(path) !SetCurrentDirectory (path)
  #define u_rename(fr,to) !MoveFile (fr, to)
  #define u_open(path) CreateFile (path, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL)
  #define u_creat(path,exec) CreateFile (path, GENERIC_WRITE, FILE_SHARE_WRITE, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL)
  #define u_creat(path,exec) CreateFile (path, GENERIC_WRITE, FILE_SHARE_WRITE, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL)
  #define u_close(handle) CloseHandle (handle)
  #define u_append(path,add) PathAppend (path, add)
  #define u_write(handle,data,len) (WriteFile (handle, data, len, &dword, 0) ? dword : -1)

  #define u_fsync(handle) FlushFileBuffers (handle)
  #define u_sync()

  #define u_lockfile(path) CreateFile (path, GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL)
  #define u_cloexec(handle)

#else

  #define _GNU_SOURCE 1
  #define _BSD_SOURCE 1
  // the above increases our chances of getting MAP_ANONYMOUS

  #include <sys/mman.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <unistd.h>
  #include <pwd.h>

  #if defined (MAP_ANON) && !defined (MAP_ANONYMOUS)
    #define MAP_ANONYMOUS MAP_ANON
  #endif

  #ifdef PATH_MAX
    #define MAX_PATH (PATH_MAX < 4096 ? 4096 : PATH_MAX)
  #else
    #define MAX_PATH 4096
  #endif

  #define u_handle int
  #define u_invalid_handle -1
  #define u_valid(fd) ((fd) >= 0)

  #define u_setenv(name,value) setenv (name, value, 1)
  #define u_mkdir(path) mkdir (path, 0777)
  #define u_chdir(path) chdir (path)
  #define u_rename(fr,to) rename (fr, to)
  #define u_open(path) open (path, O_RDONLY)
  #define u_creat(path,exec) open (path, O_WRONLY | O_CREAT | O_TRUNC, (exec) ? 0777 : 0666)
  #define u_close(handle) close (handle)
  #define u_append(path,add) strcat (strcat (path, "/"), add)
  #define u_write(handle,data,len) write (handle, data, len)

  // on a mostly idle system, a sync at the end is certainly faster, hope for the best
  #define u_fsync(handle)
  #define u_sync() sync ()

  #define u_lockfile(path) open (path, O_RDWR | O_CREAT, 0666)
  #define u_cloexec(handle) fcntl (handle, F_SETFD, FD_CLOEXEC)

#endif

#define u_16(ptr) (((ptr)[0] << 8) | (ptr)[1])
#define u_32(ptr) (((ptr)[0] << 24) | ((ptr)[1] << 16) | ((ptr)[2] << 8) | (ptr)[3])

/* some simple? dynamic memory management for paths might save ltos of ram */
static u_handle pack_handle;
static u_handle lock_handle;
static char tmppath[MAX_PATH];
static char currdir[MAX_PATH];
static char datadir[MAX_PATH];  // %AppData%/urlader
static char exe_dir[MAX_PATH];  // %AppData%/urlader/EXE_ID
static char execdir[MAX_PATH];  // %AppData%/urlader/EXE_ID/EXE_VER
static char exe_id[MAX_PATH];
static char exe_ver[MAX_PATH];

static int exe_argc;
static const char *exe_argv[MAX_ARGC];
static char exe_args[MAX_ARGS]; /* actual arguments strings copied here */
static unsigned int exe_argo;

static void
fatal (const char *msg)
{
#ifdef _WIN32
  MessageBox (0, msg, URLADER, 0);
#else
  write (2, URLADER ": ", sizeof (URLADER ": ") - 1);
  write (2, msg, strlen (msg));
  write (2, "\n", 1);
#endif

  _exit (1);
}

static void *
u_malloc (unsigned int size)
{
  void *addr;

#ifdef _WIN32
  HANDLE handle = CreateFileMapping (0, 0, PAGE_READWRITE, 0, size, NULL);

  if (!handle)
    return 0;

  addr = MapViewOfFile (handle, FILE_MAP_WRITE, 0, 0, size);

  CloseHandle (handle);
#elif defined (MAP_ANONYMOUS)
  addr = mmap (0, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);

  if (addr == (void *)-1)
    addr = 0;
#else
  addr = malloc (size);
#endif

  return addr;
}

static void
u_free (void *addr, unsigned int size)
{
#ifdef _WIN32
  UnmapViewOfFile (addr);
#elif defined (MAP_ANONYMOUS)
  munmap (addr, size);
#else
  free (addr);
#endif
}

static void *
u_mmap (u_handle h, unsigned int size)
{
  void *addr;

#ifdef _WIN32
  HANDLE handle = CreateFileMapping (h, 0, PAGE_READONLY, 0, size, NULL);

  if (!handle)
    return 0;

  addr = MapViewOfFile (handle, FILE_MAP_READ, 0, 0, size);

  CloseHandle (handle);
#else
  addr = mmap (0, size, PROT_READ, MAP_SHARED, h, 0);

  if (addr == (void *)-1)
    addr = 0;
#endif

  return addr;
}

static void
u_munmap (void *addr, unsigned int len)
{
#ifdef _WIN32
  UnmapViewOfFile (addr);
#else
  munmap (addr, len);
#endif
}

static void
tmpdir (const char *dir)
{
  static int cnt;

  for (;;)
    {
//      #ifdef _WIN32
//        sprintf (tmppath, "%s/%x_%x.tmp", dir, (unsigned int)GetCurrentProcessId (), ++cnt);
//      #else
        sprintf (tmppath, "%s/t-%x_%x.tmp", dir, (unsigned int)getpid ()             , ++cnt);
//      #endif

      if (!u_mkdir (tmppath))
        return;
    }
}

static u_handle
u_lock (const char *path, int excl, int dowait)
{
  u_handle h;

  h = u_lockfile (path);
  if (!u_valid (h))
    return h;

  u_cloexec (h);

  for (;;)
    {
      int success;

      // acquire the lock
#ifdef _WIN32
      OVERLAPPED ov = { 0 };

      success = LockFileEx (h,
                            (excl ? LOCKFILE_EXCLUSIVE_LOCK : 0)
                            | (dowait ? 0 : LOCKFILE_FAIL_IMMEDIATELY),
                            0,
                            1, 0,
                            &ov);
#else
      struct flock lck = { 0 };

      lck.l_type   = excl ? F_WRLCK : F_RDLCK;
      lck.l_whence = SEEK_SET;
      lck.l_len    = 1;

      success = !fcntl (h, dowait ? F_SETLKW : F_SETLK, &lck);
#endif

      if (!success)
        break;

      // we have the lock, now verify that the lockfile still exists

#ifdef _WIN32
      // apparently, we have to open the file to get its info :(
      BY_HANDLE_FILE_INFORMATION s1, s2;
      u_handle h2 = u_lockfile (path);
      if (!u_valid (h))
        break;

      success = GetFileInformationByHandle (h, &s1)
                && GetFileInformationByHandle (h2, &s2);

      u_close (h2);

      if (!success)
        break;

      success = s1.dwVolumeSerialNumber == s2.dwVolumeSerialNumber
             && s1.nFileIndexHigh       == s2.nFileIndexHigh
             && s1.nFileIndexLow        == s2.nFileIndexLow;
#else
      struct stat s1, s2;

      if (fstat (h, &s1) || stat (path, &s2))
        break;

      success = s1.st_dev == s2.st_dev
             && s1.st_ino == s2.st_ino;
#endif

      if (success)
        return h; // lock successfully acquired

      // files differ, close and retry - should be very rare
      u_close (h);
    }

  // failure
  u_close (h);
  return u_invalid_handle;
}

static void
systemv (const char *const argv[])
{
#ifdef _WIN32
  _spawnv (P_WAIT, argv [0], argv);
#else
  pid_t pid = fork ();

  if (pid < 0)
    fatal ("fork failure");

  if (!pid)
    {
      execv (argv [0], (void *)argv);
      _exit (124);
    }

  int status;
  waitpid (pid, &status, 0);
#endif
}

static void
deltree (const char *path)
{
  #ifdef _WIN32
    char buf[MAX_PATH * 2 + 64];
    const char *argv[] = { getenv ("COMSPEC"), "/c", "rd", "/s", "/q", buf, 0 };
    sprintf (buf, "\"%s\"", path);
  #else
    const char *argv[] = { "/bin/rm", "-rf", path, 0 };
  #endif
  systemv (argv);
}

enum
{
  T_NULL, // 5
  T_META, // 1 : exe_id, exe_ver
  T_ENV,  // 2 : name, value
  T_ARG,  // 3 : arg
  T_DIR,  // 4+: path
  T_FILE, // 4+: path, data
  T_NUM
};

enum
{
  F_EXEC = 1,
  F_LZF  = 2,
  F_NULL = 0
};

struct hdr
{
  unsigned char type;
  unsigned char flags;
  unsigned char namelen[2];
  unsigned char datalen[4];
};

struct tail {
  unsigned char max_filesize[4];
  unsigned char size[4];
  char magic[12];
};

static char *pack_base, *pack_end;
static struct hdr *pack_cur;
static char *scratch;
static unsigned int scratch_size;

#define PACK_NAME ((char *)(pack_cur + 1))
#define PACK_DATA (PACK_NAME + u_16 (pack_cur->namelen) + 1)
#define PACK_VALID pack_cur->type

static void
pack_next (void)
{
  unsigned int d = u_32 (pack_cur->datalen);

  pack_cur = (struct hdr *)(PACK_DATA + d);
}

static void
pack_unmap (void)
{
  if (pack_base)
    {
      u_munmap (pack_base, pack_end - pack_base);
      pack_base = 0;
    }

  if (scratch)
    {
      u_free (scratch, scratch_size);
      scratch = 0;
    }
}

static int
pack_map (void)
{
  char *addr;
  unsigned int size;

#ifdef _WIN32
  BY_HANDLE_FILE_INFORMATION fi;

  if (!GetFileInformationByHandle (pack_handle, &fi))
    return 0;

  size = fi.nFileSizeLow;
#else
  size = lseek (pack_handle, 0, SEEK_END);
#endif

  addr = u_mmap (pack_handle, size);
  if (!addr)
    return 0;

  pack_unmap ();

  pack_base = addr;
  pack_end  = pack_base + size;

  struct tail *tail;

  tail = (void *)(pack_end - sizeof (*tail));

  if (memcmp (tail->magic, TAIL_MAGIC, sizeof (TAIL_MAGIC) - 1))
    return 0;

  pack_cur = (struct hdr *)(pack_end - u_32 (tail->size));

  scratch = u_malloc (scratch_size = u_32 (tail->max_filesize));
  if (!scratch)
    return 0;

  return 1;
}

static void
exe_info (void)
{
  if (!pack_map ())
    fatal ("unable to locate packfile in executable - executable corrupted?");

  if (pack_cur->type != T_META)
    fatal ("unable to locate executable metadata - executable corrupted?");

  strcpy (exe_id, PACK_NAME);
}

static void
load (void)
{
  u_mkdir (datadir);

  strcpy (exe_dir, datadir);
  u_append (exe_dir, exe_id);
  u_mkdir (exe_dir);

  if (u_chdir (exe_dir))
    fatal ("unable to change to application data directory");

  u_handle h = u_open ("override");
  if (u_valid (h))
    {
      u_handle oh = pack_handle;

      pack_handle = h;
      if (!pack_map ())
        {
          pack_handle = oh;
          oh = h;
        }

      u_close (oh);
    }

  if (pack_cur->type != T_META)
    fatal ("unable to locate override metadata");

  strcpy (exe_ver, PACK_DATA);
  pack_next ();

  for (;;)
    {
      if (pack_cur->type == T_ENV)
        u_setenv (PACK_NAME, PACK_DATA);
      else if (pack_cur->type == T_ARG)
        {
          int len = u_16 (pack_cur->namelen) + 1;
          exe_argv [exe_argc++] = exe_args + exe_argo;
          memcpy (exe_args + exe_argo, PACK_NAME, len);
          exe_argo += len;
        }
      else
        break;

      pack_next ();
    }
 
done_env_arg:
  strcpy (execdir, exe_dir);
  u_append (execdir, "i-");
  strcat (execdir, exe_ver);

  strcat (strcpy (tmppath, execdir), ".lck");
  lock_handle = u_lock (tmppath, 0, 1);
  if (!lock_handle)
    fatal ("unable to lock application instance");

  if (access (execdir, F_OK))
    {
      // does not exist yet, so unpack and move
      tmpdir (exe_dir);

      if (u_chdir (tmppath))
        fatal ("unable to change to new instance directory");

      for (;;)
        {
          switch (pack_cur->type)
            {
              case T_DIR:
                u_mkdir (PACK_NAME);
                break;

              case T_FILE:
                {
                  u_handle h = u_creat (PACK_NAME, pack_cur->flags & F_EXEC);
                  unsigned int dlen, len = u_32 (pack_cur->datalen);
                  char *data = PACK_DATA;

                  if (pack_cur->flags & F_LZF)
                    if (dlen = lzf_decompress (data, len, scratch, scratch_size))
                      {
                        data = scratch;
                        len  = dlen;
                      }
                    else
                      fatal ("unable to uncompress file data - pack corrupted?");

                  if (!u_valid (h))
                    fatal ("unable to unpack file from packfile - disk full?");

                  if (u_write (h, data, len) != len)
                    fatal ("unable to unpack file from packfile - disk full?");

                  u_fsync (h);
                  u_close (h);
                }
                break;

              case T_NULL:
                goto done;
            }

          pack_next ();
        }

done:
      if (u_chdir (datadir))
        fatal ("unable to change to data directory");

      u_sync ();

      if (u_rename (tmppath, execdir))
        deltree (tmppath); // if move fails, delete new, assume other process created it independently
    }

  pack_unmap ();
  u_close (pack_handle);

  if (u_chdir (execdir))
    fatal ("unable to change to application instance directory");

  u_setenv ("URLADER_VERSION", URLADER_VERSION);
  u_setenv ("URLADER_DATADIR", datadir);
  u_setenv ("URLADER_EXECDIR", execdir);
  u_setenv ("URLADER_EXE_ID" , exe_id);
  u_setenv ("URLADER_EXE_DIR", exe_dir);
  u_setenv ("URLADER_EXE_VER", exe_ver);

#if 0
  // yes, this is overkill
  u_setenv ("SHLIB_PATH"        , execdir); // hpux
  u_setenv ("LIBPATH"           , execdir); // aix
  u_setenv ("LD_LIBRARY_PATH"   , execdir); // most elf systems
  u_setenv ("LD_LIBRARY_PATH_32", execdir); // solaris
  u_setenv ("LD_LIBRARY_PATH_64", execdir); // solaris
  u_setenv ("LD_LIBRARYN32_PATH", execdir); // irix
  u_setenv ("LD_LIBRARY64_PATH" , execdir); // irix
  u_setenv ("DYLD_LIBRARY_PATH" , execdir); // os sucks from apple
#endif
}

static void
execute (void)
{
  exe_argv [exe_argc] = 0;
  systemv (exe_argv);
}

#ifdef _WIN32

int APIENTRY
WinMain (HINSTANCE hI, HINSTANCE hP, LPSTR argv, int command_show)
{
  if (!GetModuleFileName (hI, tmppath, sizeof (tmppath)))
    fatal ("unable to find executable pack");

  pack_handle = u_open (tmppath);
  if (!u_valid (pack_handle))
    fatal ("unable to open executable pack");

  exe_info ();

  if (!GetCurrentDirectory (sizeof (currdir), currdir))
    strcpy (currdir, ".");

  if (SHGetFolderPath (0, CSIDL_APPDATA | CSIDL_FLAG_CREATE, NULL, SHGFP_TYPE_CURRENT, datadir) != S_OK)
    fatal ("unable to find application data directory");

  u_mkdir (datadir);
  u_append (datadir, URLADER);

  load ();
  execute ();

  return 0;
}

#else

int
main (int argc, char *argv[])
{
  char *home = getenv ("HOME");

  pack_handle = u_open (argv [0]);
  if (!u_valid (pack_handle))
    fatal ("unable to open executable pack");

  exe_info ();

  if (!home)
    {
      struct passwd *pw;

      if ((pw = getpwuid (getuid ())))
        home = pw->pw_dir;
      else
        home = "/tmp";
    }

  if (!getcwd (currdir, sizeof (currdir)))
    strcpy (currdir, ".");

  u_mkdir (home);
  //strcat (strcat (strcpy (datadir, home), "/."), URLADER);
  sprintf (datadir, "%s/.%s", home, URLADER);
  u_mkdir (datadir);

#if 0
  if (gethostname (tmppath, sizeof (tmppath)))
    strcpy (tmppath, "default");

  u_append (datadir, tmppath);
#endif

  load ();
  execute ();

  return 0;
}

#endif

Revision:	1.7
Committed:	Fri Dec 30 14:51:45 2011 UTC (12 years, 4 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.6:	+74 -39 lines
Log Message:	* empty log message *
#	Content
1	#ifndef URLADER
2	# define URLADER "urlader"
3	#endif
4	#define URLADER_VERSION "1.0" // a decimal number, not a version string
5
6	#define MAX_ARGC 32
7	#define MAX_ARGS 256
8
9	#include <stdio.h>
10	#include <stdlib.h>
11	#include <unistd.h>
12	#include <errno.h>
13	#include <string.h>
14	#include <time.h>
15	#include <fcntl.h>
16
17	#include "liblzf/lzf_d.c"
18
19	#define TAIL_MAGIC "SCHMORPPACK0"
20
21	#ifdef _WIN32
22
23	#include <windows.h>
24	//#include <winbase.h>
25	#include <shlobj.h>
26	#include <shlwapi.h>
27	#include <wininet.h>
28
29	static DWORD dword;
30
31	#define u_handle HANDLE
32	#define u_invalid_handle 0
33	#define u_valid(handle) (!!handle)
34
35	#define u_setenv(name,value) SetEnvironmentVariable (name, value)
36	#define u_mkdir(path) !CreateDirectory (path, NULL)
37	#define u_chdir(path) !SetCurrentDirectory (path)
38	#define u_rename(fr,to) !MoveFile (fr, to)
39	#define u_open(path) CreateFile (path, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL \| FILE_FLAG_SEQUENTIAL_SCAN, NULL)
40	#define u_creat(path,exec) CreateFile (path, GENERIC_WRITE, FILE_SHARE_WRITE, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL \| FILE_FLAG_SEQUENTIAL_SCAN, NULL)
41	#define u_creat(path,exec) CreateFile (path, GENERIC_WRITE, FILE_SHARE_WRITE, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL \| FILE_FLAG_SEQUENTIAL_SCAN, NULL)
42	#define u_close(handle) CloseHandle (handle)
43	#define u_append(path,add) PathAppend (path, add)
44	#define u_write(handle,data,len) (WriteFile (handle, data, len, &dword, 0) ? dword : -1)
45
46	#define u_fsync(handle) FlushFileBuffers (handle)
47	#define u_sync()
48
49	#define u_lockfile(path) CreateFile (path, GENERIC_READ \| GENERIC_WRITE, FILE_SHARE_READ \| FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL)
50	#define u_cloexec(handle)
51
52	#else
53
54	#define _GNU_SOURCE 1
55	#define _BSD_SOURCE 1
56	// the above increases our chances of getting MAP_ANONYMOUS
57
58	#include <sys/mman.h>
59	#include <sys/types.h>
60	#include <sys/stat.h>
61	#include <unistd.h>
62	#include <pwd.h>
63
64	#if defined (MAP_ANON) && !defined (MAP_ANONYMOUS)
65	#define MAP_ANONYMOUS MAP_ANON
66	#endif
67
68	#ifdef PATH_MAX
69	#define MAX_PATH (PATH_MAX < 4096 ? 4096 : PATH_MAX)
70	#else
71	#define MAX_PATH 4096
72	#endif
73
74	#define u_handle int
75	#define u_invalid_handle -1
76	#define u_valid(fd) ((fd) >= 0)
77
78	#define u_setenv(name,value) setenv (name, value, 1)
79	#define u_mkdir(path) mkdir (path, 0777)
80	#define u_chdir(path) chdir (path)
81	#define u_rename(fr,to) rename (fr, to)
82	#define u_open(path) open (path, O_RDONLY)
83	#define u_creat(path,exec) open (path, O_WRONLY \| O_CREAT \| O_TRUNC, (exec) ? 0777 : 0666)
84	#define u_close(handle) close (handle)
85	#define u_append(path,add) strcat (strcat (path, "/"), add)
86	#define u_write(handle,data,len) write (handle, data, len)
87
88	// on a mostly idle system, a sync at the end is certainly faster, hope for the best
89	#define u_fsync(handle)
90	#define u_sync() sync ()
91
92	#define u_lockfile(path) open (path, O_RDWR \| O_CREAT, 0666)
93	#define u_cloexec(handle) fcntl (handle, F_SETFD, FD_CLOEXEC)
94
95	#endif
96
97	#define u_16(ptr) (((ptr)[0] << 8) \| (ptr)[1])
98	#define u_32(ptr) (((ptr)[0] << 24) \| ((ptr)[1] << 16) \| ((ptr)[2] << 8) \| (ptr)[3])
99
100	/* some simple? dynamic memory management for paths might save ltos of ram */
101	static u_handle pack_handle;
102	static u_handle lock_handle;
103	static char tmppath[MAX_PATH];
104	static char currdir[MAX_PATH];
105	static char datadir[MAX_PATH]; // %AppData%/urlader
106	static char exe_dir[MAX_PATH]; // %AppData%/urlader/EXE_ID
107	static char execdir[MAX_PATH]; // %AppData%/urlader/EXE_ID/EXE_VER
108	static char exe_id[MAX_PATH];
109	static char exe_ver[MAX_PATH];
110
111	static int exe_argc;
112	static const char *exe_argv[MAX_ARGC];
113	static char exe_args[MAX_ARGS]; /* actual arguments strings copied here */
114	static unsigned int exe_argo;
115
116	static void
117	fatal (const char *msg)
118	{
119	#ifdef _WIN32
120	MessageBox (0, msg, URLADER, 0);
121	#else
122	write (2, URLADER ": ", sizeof (URLADER ": ") - 1);
123	write (2, msg, strlen (msg));
124	write (2, "\n", 1);
125	#endif
126
127	_exit (1);
128	}
129
130	static void *
131	u_malloc (unsigned int size)
132	{
133	void *addr;
134
135	#ifdef _WIN32
136	HANDLE handle = CreateFileMapping (0, 0, PAGE_READWRITE, 0, size, NULL);
137
138	if (!handle)
139	return 0;
140
141	addr = MapViewOfFile (handle, FILE_MAP_WRITE, 0, 0, size);
142
143	CloseHandle (handle);
144	#elif defined (MAP_ANONYMOUS)
145	addr = mmap (0, size, PROT_READ \| PROT_WRITE, MAP_PRIVATE \| MAP_ANON, -1, 0);
146
147	if (addr == (void *)-1)
148	addr = 0;
149	#else
150	addr = malloc (size);
151	#endif
152
153	return addr;
154	}
155
156	static void
157	u_free (void *addr, unsigned int size)
158	{
159	#ifdef _WIN32
160	UnmapViewOfFile (addr);
161	#elif defined (MAP_ANONYMOUS)
162	munmap (addr, size);
163	#else
164	free (addr);
165	#endif
166	}
167
168	static void *
169	u_mmap (u_handle h, unsigned int size)
170	{
171	void *addr;
172
173	#ifdef _WIN32
174	HANDLE handle = CreateFileMapping (h, 0, PAGE_READONLY, 0, size, NULL);
175
176	if (!handle)
177	return 0;
178
179	addr = MapViewOfFile (handle, FILE_MAP_READ, 0, 0, size);
180
181	CloseHandle (handle);
182	#else
183	addr = mmap (0, size, PROT_READ, MAP_SHARED, h, 0);
184
185	if (addr == (void *)-1)
186	addr = 0;
187	#endif
188
189	return addr;
190	}
191
192	static void
193	u_munmap (void *addr, unsigned int len)
194	{
195	#ifdef _WIN32
196	UnmapViewOfFile (addr);
197	#else
198	munmap (addr, len);
199	#endif
200	}
201
202	static void
203	tmpdir (const char *dir)
204	{
205	static int cnt;
206
207	for (;;)
208	{
209	// #ifdef _WIN32
210	// sprintf (tmppath, "%s/%x_%x.tmp", dir, (unsigned int)GetCurrentProcessId (), ++cnt);
211	// #else
212	sprintf (tmppath, "%s/t-%x_%x.tmp", dir, (unsigned int)getpid () , ++cnt);
213	// #endif
214
215	if (!u_mkdir (tmppath))
216	return;
217	}
218	}
219
220	static u_handle
221	u_lock (const char *path, int excl, int dowait)
222	{
223	u_handle h;
224
225	h = u_lockfile (path);
226	if (!u_valid (h))
227	return h;
228
229	u_cloexec (h);
230
231	for (;;)
232	{
233	int success;
234
235	// acquire the lock
236	#ifdef _WIN32
237	OVERLAPPED ov = { 0 };
238
239	success = LockFileEx (h,
240	(excl ? LOCKFILE_EXCLUSIVE_LOCK : 0)
241	\| (dowait ? 0 : LOCKFILE_FAIL_IMMEDIATELY),
242	0,
243	1, 0,
244	&ov);
245	#else
246	struct flock lck = { 0 };
247
248	lck.l_type = excl ? F_WRLCK : F_RDLCK;
249	lck.l_whence = SEEK_SET;
250	lck.l_len = 1;
251
252	success = !fcntl (h, dowait ? F_SETLKW : F_SETLK, &lck);
253	#endif
254
255	if (!success)
256	break;
257
258	// we have the lock, now verify that the lockfile still exists
259
260	#ifdef _WIN32
261	// apparently, we have to open the file to get its info :(
262	BY_HANDLE_FILE_INFORMATION s1, s2;
263	u_handle h2 = u_lockfile (path);
264	if (!u_valid (h))
265	break;
266
267	success = GetFileInformationByHandle (h, &s1)
268	&& GetFileInformationByHandle (h2, &s2);
269
270	u_close (h2);
271
272	if (!success)
273	break;
274
275	success = s1.dwVolumeSerialNumber == s2.dwVolumeSerialNumber
276	&& s1.nFileIndexHigh == s2.nFileIndexHigh
277	&& s1.nFileIndexLow == s2.nFileIndexLow;
278	#else
279	struct stat s1, s2;
280
281	if (fstat (h, &s1) \|\| stat (path, &s2))
282	break;
283
284	success = s1.st_dev == s2.st_dev
285	&& s1.st_ino == s2.st_ino;
286	#endif
287
288	if (success)
289	return h; // lock successfully acquired
290
291	// files differ, close and retry - should be very rare
292	u_close (h);
293	}
294
295	// failure
296	u_close (h);
297	return u_invalid_handle;
298	}
299
300	static void
301	systemv (const char *const argv[])
302	{
303	#ifdef _WIN32
304	_spawnv (P_WAIT, argv [0], argv);
305	#else
306	pid_t pid = fork ();
307
308	if (pid < 0)
309	fatal ("fork failure");
310
311	if (!pid)
312	{
313	execv (argv [0], (void *)argv);
314	_exit (124);
315	}
316
317	int status;
318	waitpid (pid, &status, 0);
319	#endif
320	}
321
322	static void
323	deltree (const char *path)
324	{
325	#ifdef _WIN32
326	char buf[MAX_PATH * 2 + 64];
327	const char *argv[] = { getenv ("COMSPEC"), "/c", "rd", "/s", "/q", buf, 0 };
328	sprintf (buf, "\"%s\"", path);
329	#else
330	const char *argv[] = { "/bin/rm", "-rf", path, 0 };
331	#endif
332	systemv (argv);
333	}
334
335	enum
336	{
337	T_NULL, // 5
338	T_META, // 1 : exe_id, exe_ver
339	T_ENV, // 2 : name, value
340	T_ARG, // 3 : arg
341	T_DIR, // 4+: path
342	T_FILE, // 4+: path, data
343	T_NUM
344	};
345
346	enum
347	{
348	F_EXEC = 1,
349	F_LZF = 2,
350	F_NULL = 0
351	};
352
353	struct hdr
354	{
355	unsigned char type;
356	unsigned char flags;
357	unsigned char namelen[2];
358	unsigned char datalen[4];
359	};
360
361	struct tail {
362	unsigned char max_filesize[4];
363	unsigned char size[4];
364	char magic[12];
365	};
366
367	static char pack_base, pack_end;
368	static struct hdr *pack_cur;
369	static char *scratch;
370	static unsigned int scratch_size;
371
372	#define PACK_NAME ((char *)(pack_cur + 1))
373	#define PACK_DATA (PACK_NAME + u_16 (pack_cur->namelen) + 1)
374	#define PACK_VALID pack_cur->type
375
376	static void
377	pack_next (void)
378	{
379	unsigned int d = u_32 (pack_cur->datalen);
380
381	pack_cur = (struct hdr *)(PACK_DATA + d);
382	}
383
384	static void
385	pack_unmap (void)
386	{
387	if (pack_base)
388	{
389	u_munmap (pack_base, pack_end - pack_base);
390	pack_base = 0;
391	}
392
393	if (scratch)
394	{
395	u_free (scratch, scratch_size);
396	scratch = 0;
397	}
398	}
399
400	static int
401	pack_map (void)
402	{
403	char *addr;
404	unsigned int size;
405
406	#ifdef _WIN32
407	BY_HANDLE_FILE_INFORMATION fi;
408
409	if (!GetFileInformationByHandle (pack_handle, &fi))
410	return 0;
411
412	size = fi.nFileSizeLow;
413	#else
414	size = lseek (pack_handle, 0, SEEK_END);
415	#endif
416
417	addr = u_mmap (pack_handle, size);
418	if (!addr)
419	return 0;
420
421	pack_unmap ();
422
423	pack_base = addr;
424	pack_end = pack_base + size;
425
426	struct tail *tail;
427
428	tail = (void )(pack_end - sizeof (tail));
429
430	if (memcmp (tail->magic, TAIL_MAGIC, sizeof (TAIL_MAGIC) - 1))
431	return 0;
432
433	pack_cur = (struct hdr *)(pack_end - u_32 (tail->size));
434
435	scratch = u_malloc (scratch_size = u_32 (tail->max_filesize));
436	if (!scratch)
437	return 0;
438
439	return 1;
440	}
441
442	static void
443	exe_info (void)
444	{
445	if (!pack_map ())
446	fatal ("unable to locate packfile in executable - executable corrupted?");
447
448	if (pack_cur->type != T_META)
449	fatal ("unable to locate executable metadata - executable corrupted?");
450
451	strcpy (exe_id, PACK_NAME);
452	}
453
454	static void
455	load (void)
456	{
457	u_mkdir (datadir);
458
459	strcpy (exe_dir, datadir);
460	u_append (exe_dir, exe_id);
461	u_mkdir (exe_dir);
462
463	if (u_chdir (exe_dir))
464	fatal ("unable to change to application data directory");
465
466	u_handle h = u_open ("override");
467	if (u_valid (h))
468	{
469	u_handle oh = pack_handle;
470
471	pack_handle = h;
472	if (!pack_map ())
473	{
474	pack_handle = oh;
475	oh = h;
476	}
477
478	u_close (oh);
479	}
480
481	if (pack_cur->type != T_META)
482	fatal ("unable to locate override metadata");
483
484	strcpy (exe_ver, PACK_DATA);
485	pack_next ();
486
487	for (;;)
488	{
489	if (pack_cur->type == T_ENV)
490	u_setenv (PACK_NAME, PACK_DATA);
491	else if (pack_cur->type == T_ARG)
492	{
493	int len = u_16 (pack_cur->namelen) + 1;
494	exe_argv [exe_argc++] = exe_args + exe_argo;
495	memcpy (exe_args + exe_argo, PACK_NAME, len);
496	exe_argo += len;
497	}
498	else
499	break;
500
501	pack_next ();
502	}
503
504	done_env_arg:
505	strcpy (execdir, exe_dir);
506	u_append (execdir, "i-");
507	strcat (execdir, exe_ver);
508
509	strcat (strcpy (tmppath, execdir), ".lck");
510	lock_handle = u_lock (tmppath, 0, 1);
511	if (!lock_handle)
512	fatal ("unable to lock application instance");
513
514	if (access (execdir, F_OK))
515	{
516	// does not exist yet, so unpack and move
517	tmpdir (exe_dir);
518
519	if (u_chdir (tmppath))
520	fatal ("unable to change to new instance directory");
521
522	for (;;)
523	{
524	switch (pack_cur->type)
525	{
526	case T_DIR:
527	u_mkdir (PACK_NAME);
528	break;
529
530	case T_FILE:
531	{
532	u_handle h = u_creat (PACK_NAME, pack_cur->flags & F_EXEC);
533	unsigned int dlen, len = u_32 (pack_cur->datalen);
534	char *data = PACK_DATA;
535
536	if (pack_cur->flags & F_LZF)
537	if (dlen = lzf_decompress (data, len, scratch, scratch_size))
538	{
539	data = scratch;
540	len = dlen;
541	}
542	else
543	fatal ("unable to uncompress file data - pack corrupted?");
544
545	if (!u_valid (h))
546	fatal ("unable to unpack file from packfile - disk full?");
547
548	if (u_write (h, data, len) != len)
549	fatal ("unable to unpack file from packfile - disk full?");
550
551	u_fsync (h);
552	u_close (h);
553	}
554	break;
555
556	case T_NULL:
557	goto done;
558	}
559
560	pack_next ();
561	}
562
563	done:
564	if (u_chdir (datadir))
565	fatal ("unable to change to data directory");
566
567	u_sync ();
568
569	if (u_rename (tmppath, execdir))
570	deltree (tmppath); // if move fails, delete new, assume other process created it independently
571	}
572
573	pack_unmap ();
574	u_close (pack_handle);
575
576	if (u_chdir (execdir))
577	fatal ("unable to change to application instance directory");
578
579	u_setenv ("URLADER_VERSION", URLADER_VERSION);
580	u_setenv ("URLADER_DATADIR", datadir);
581	u_setenv ("URLADER_EXECDIR", execdir);
582	u_setenv ("URLADER_EXE_ID" , exe_id);
583	u_setenv ("URLADER_EXE_DIR", exe_dir);
584	u_setenv ("URLADER_EXE_VER", exe_ver);
585
586	#if 0
587	// yes, this is overkill
588	u_setenv ("SHLIB_PATH" , execdir); // hpux
589	u_setenv ("LIBPATH" , execdir); // aix
590	u_setenv ("LD_LIBRARY_PATH" , execdir); // most elf systems
591	u_setenv ("LD_LIBRARY_PATH_32", execdir); // solaris
592	u_setenv ("LD_LIBRARY_PATH_64", execdir); // solaris
593	u_setenv ("LD_LIBRARYN32_PATH", execdir); // irix
594	u_setenv ("LD_LIBRARY64_PATH" , execdir); // irix
595	u_setenv ("DYLD_LIBRARY_PATH" , execdir); // os sucks from apple
596	#endif
597	}
598
599	static void
600	execute (void)
601	{
602	exe_argv [exe_argc] = 0;
603	systemv (exe_argv);
604	}
605
606	#ifdef _WIN32
607
608	int APIENTRY
609	WinMain (HINSTANCE hI, HINSTANCE hP, LPSTR argv, int command_show)
610	{
611	if (!GetModuleFileName (hI, tmppath, sizeof (tmppath)))
612	fatal ("unable to find executable pack");
613
614	pack_handle = u_open (tmppath);
615	if (!u_valid (pack_handle))
616	fatal ("unable to open executable pack");
617
618	exe_info ();
619
620	if (!GetCurrentDirectory (sizeof (currdir), currdir))
621	strcpy (currdir, ".");
622
623	if (SHGetFolderPath (0, CSIDL_APPDATA \| CSIDL_FLAG_CREATE, NULL, SHGFP_TYPE_CURRENT, datadir) != S_OK)
624	fatal ("unable to find application data directory");
625
626	u_mkdir (datadir);
627	u_append (datadir, URLADER);
628
629	load ();
630	execute ();
631
632	return 0;
633	}
634
635	#else
636
637	int
638	main (int argc, char *argv[])
639	{
640	char *home = getenv ("HOME");
641
642	pack_handle = u_open (argv [0]);
643	if (!u_valid (pack_handle))
644	fatal ("unable to open executable pack");
645
646	exe_info ();
647
648	if (!home)
649	{
650	struct passwd *pw;
651
652	if ((pw = getpwuid (getuid ())))
653	home = pw->pw_dir;
654	else
655	home = "/tmp";
656	}
657
658	if (!getcwd (currdir, sizeof (currdir)))
659	strcpy (currdir, ".");
660
661	u_mkdir (home);
662	//strcat (strcat (strcpy (datadir, home), "/."), URLADER);
663	sprintf (datadir, "%s/.%s", home, URLADER);
664	u_mkdir (datadir);
665
666	#if 0
667	if (gethostname (tmppath, sizeof (tmppath)))
668	strcpy (tmppath, "default");
669
670	u_append (datadir, tmppath);
671	#endif
672
673	load ();
674	execute ();
675
676	return 0;
677	}
678
679	#endif
680