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/cvs/Urlader/urlib.c
Revision: 1.2
Committed: Mon Jan 2 09:23:04 2012 UTC (12 years, 9 months ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.1: +97 -16 lines
Log Message:
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File Contents

# User Rev Content
1 root 1.1 #include "urlib.h"
2    
3     #include <fcntl.h>
4 root 1.2 #include <stdio.h>
5     #include <string.h>
6     #include <stdlib.h>
7 root 1.1
8     #ifdef _WIN32
9    
10     #include <windows.h>
11     //#include <winbase.h>
12     #include <shlobj.h>
13     #include <shlwapi.h>
14     #include <wininet.h>
15    
16     static DWORD dword;
17    
18     #define u_handle HANDLE
19     #define u_invalid_handle 0
20     #define u_valid(handle) (!!handle)
21    
22     #define u_setenv(name,value) SetEnvironmentVariable (name, value)
23     #define u_mkdir(path) !CreateDirectory (path, NULL)
24     #define u_chdir(path) !SetCurrentDirectory (path)
25     #define u_rename(fr,to) !MoveFile (fr, to)
26     #define u_open(path) CreateFile (path, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL)
27     #define u_creat(path,exec) CreateFile (path, GENERIC_WRITE, FILE_SHARE_WRITE, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL)
28     #define u_creat(path,exec) CreateFile (path, GENERIC_WRITE, FILE_SHARE_WRITE, NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL)
29     #define u_close(handle) CloseHandle (handle)
30     #define u_append(path,add) PathAppend (path, add)
31     #define u_write(handle,data,len) (WriteFile (handle, data, len, &dword, 0) ? dword : -1)
32    
33     #define u_fsync(handle) FlushFileBuffers (handle)
34     #define u_sync()
35    
36     #define u_lockfile(path) CreateFile (path, GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL)
37     #define u_cloexec(handle)
38    
39     #else
40    
41     #define _GNU_SOURCE 1
42     #define _BSD_SOURCE 1
43     // the above increases our chances of getting MAP_ANONYMOUS
44    
45     #include <sys/mman.h>
46     #include <sys/types.h>
47     #include <sys/stat.h>
48     #include <unistd.h>
49     #include <pwd.h>
50    
51     #if defined (MAP_ANON) && !defined (MAP_ANONYMOUS)
52     #define MAP_ANONYMOUS MAP_ANON
53     #endif
54    
55     #ifdef PATH_MAX
56     #define MAX_PATH (PATH_MAX < 4096 ? 4096 : PATH_MAX)
57     #else
58     #define MAX_PATH 4096
59     #endif
60    
61     #define u_handle int
62     #define u_invalid_handle -1
63     #define u_valid(fd) ((fd) >= 0)
64    
65     #define u_setenv(name,value) setenv (name, value, 1)
66     #define u_mkdir(path) mkdir (path, 0777)
67     #define u_chdir(path) chdir (path)
68     #define u_rename(fr,to) rename (fr, to)
69     #define u_open(path) open (path, O_RDONLY)
70     #define u_creat(path,exec) open (path, O_WRONLY | O_CREAT | O_TRUNC, (exec) ? 0777 : 0666)
71     #define u_close(handle) close (handle)
72     #define u_append(path,add) strcat (strcat (path, "/"), add)
73     #define u_write(handle,data,len) write (handle, data, len)
74    
75     // on a mostly idle system, a sync at the end is certainly faster, hope for the best
76     #define u_fsync(handle)
77     #define u_sync() sync ()
78    
79     #define u_lockfile(path) open (path, O_RDWR | O_CREAT, 0666)
80     #define u_cloexec(handle) fcntl (handle, F_SETFD, FD_CLOEXEC)
81    
82     #endif
83    
84     #define u_16(ptr) (((ptr)[0] << 8) | (ptr)[1])
85     #define u_32(ptr) (((ptr)[0] << 24) | ((ptr)[1] << 16) | ((ptr)[2] << 8) | (ptr)[3])
86    
87 root 1.2 static char currdir[MAX_PATH];
88     static char datadir[MAX_PATH]; // %AppData%/urlader
89     static char exe_dir[MAX_PATH]; // %AppData%/urlader/EXE_ID
90     static char execdir[MAX_PATH]; // %AppData%/urlader/EXE_ID/EXE_VER
91     static char exe_id[MAX_PATH];
92     static char exe_ver[MAX_PATH];
93    
94     /////////////////////////////////////////////////////////////////////////////
95    
96     static void
97     u_fatal (const char *msg)
98     {
99     #ifdef _WIN32
100     MessageBox (0, msg, URLADER, 0);
101     #else
102     write (2, URLADER ": ", sizeof (URLADER ": ") - 1);
103     write (2, msg, strlen (msg));
104     write (2, "\n", 1);
105     #endif
106    
107     _exit (1);
108     }
109    
110 root 1.1 static void *
111     u_malloc (unsigned int size)
112     {
113     void *addr;
114    
115     #ifdef _WIN32
116     HANDLE handle = CreateFileMapping (0, 0, PAGE_READWRITE, 0, size, NULL);
117    
118     if (!handle)
119     return 0;
120    
121     addr = MapViewOfFile (handle, FILE_MAP_WRITE, 0, 0, size);
122    
123     CloseHandle (handle);
124     #elif defined (MAP_ANONYMOUS)
125     addr = mmap (0, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0);
126    
127     if (addr == (void *)-1)
128     addr = 0;
129     #else
130     addr = malloc (size);
131     #endif
132    
133     return addr;
134     }
135    
136     static void
137     u_free (void *addr, unsigned int size)
138     {
139     #ifdef _WIN32
140     UnmapViewOfFile (addr);
141     #elif defined (MAP_ANONYMOUS)
142     munmap (addr, size);
143     #else
144     free (addr);
145     #endif
146     }
147    
148     static void *
149     u_mmap (u_handle h, unsigned int size)
150     {
151     void *addr;
152    
153     #ifdef _WIN32
154     HANDLE handle = CreateFileMapping (h, 0, PAGE_READONLY, 0, size, NULL);
155    
156     if (!handle)
157     return 0;
158    
159     addr = MapViewOfFile (handle, FILE_MAP_READ, 0, 0, size);
160    
161     CloseHandle (handle);
162     #else
163     addr = mmap (0, size, PROT_READ, MAP_SHARED, h, 0);
164    
165     if (addr == (void *)-1)
166     addr = 0;
167     #endif
168    
169     return addr;
170     }
171    
172     static void
173     u_munmap (void *addr, unsigned int len)
174     {
175     #ifdef _WIN32
176     UnmapViewOfFile (addr);
177     #else
178     munmap (addr, len);
179     #endif
180     }
181 root 1.2
182     /////////////////////////////////////////////////////////////////////////////
183    
184     static void
185     u_set_datadir (void)
186     {
187     #ifdef _WIN32
188     if (SHGetFolderPath (0, CSIDL_APPDATA | CSIDL_FLAG_CREATE, NULL, SHGFP_TYPE_CURRENT, datadir) != S_OK)
189     u_fatal ("unable to find application data directory");
190    
191     u_mkdir (datadir);
192     u_append (datadir, URLADER);
193    
194     #else
195     char *home = getenv ("HOME");
196    
197     if (!home)
198     {
199     struct passwd *pw;
200    
201     if ((pw = getpwuid (getuid ())))
202     home = pw->pw_dir;
203     else
204     home = "/tmp";
205     }
206    
207     u_mkdir (home);
208     //strcat (strcat (strcpy (datadir, home), "/."), URLADER);
209     sprintf (datadir, "%s/.%s", home, URLADER);
210     #endif
211    
212     u_setenv ("URLADER_DATADIR", datadir);
213     }
214    
215     static void
216     u_set_exe_info (void)
217     {
218     strcpy (exe_dir, datadir);
219     u_append (exe_dir, exe_id);
220     u_mkdir (exe_dir);
221    
222     strcpy (execdir, exe_dir);
223     u_append (execdir, "i-");
224     strcat (execdir, exe_ver);
225    
226     u_setenv ("URLADER_EXECDIR", execdir);
227     u_setenv ("URLADER_EXE_ID" , exe_id);
228     u_setenv ("URLADER_EXE_DIR", exe_dir);
229     u_setenv ("URLADER_EXE_VER", exe_ver);
230     }
231    
232     /////////////////////////////////////////////////////////////////////////////
233    
234 root 1.1 static u_handle
235     u_lock (const char *path, int excl, int dowait)
236     {
237     u_handle h;
238    
239     h = u_lockfile (path);
240     if (!u_valid (h))
241     return h;
242    
243     u_cloexec (h);
244    
245     for (;;)
246     {
247     int success;
248    
249     // acquire the lock
250     #ifdef _WIN32
251     OVERLAPPED ov = { 0 };
252    
253     success = LockFileEx (h,
254     (excl ? LOCKFILE_EXCLUSIVE_LOCK : 0)
255     | (dowait ? 0 : LOCKFILE_FAIL_IMMEDIATELY),
256     0,
257     1, 0,
258     &ov);
259     #else
260     struct flock lck = { 0 };
261    
262     lck.l_type = excl ? F_WRLCK : F_RDLCK;
263     lck.l_whence = SEEK_SET;
264     lck.l_len = 1;
265    
266     success = !fcntl (h, dowait ? F_SETLKW : F_SETLK, &lck);
267     #endif
268    
269     if (!success)
270     break;
271    
272     // we have the lock, now verify that the lockfile still exists
273    
274     #ifdef _WIN32
275     // apparently, we have to open the file to get its info :(
276 root 1.2 {
277     BY_HANDLE_FILE_INFORMATION s1, s2;
278     u_handle h2 = u_lockfile (path);
279     if (!u_valid (h))
280     break;
281    
282     success = GetFileInformationByHandle (h, &s1)
283     && GetFileInformationByHandle (h2, &s2);
284    
285     u_close (h2);
286    
287     if (!success)
288     break;
289    
290     success = s1.dwVolumeSerialNumber == s2.dwVolumeSerialNumber
291     && s1.nFileIndexHigh == s2.nFileIndexHigh
292     && s1.nFileIndexLow == s2.nFileIndexLow;
293     }
294 root 1.1 #else
295     struct stat s1, s2;
296    
297     if (fstat (h, &s1) || stat (path, &s2))
298     break;
299    
300     success = s1.st_dev == s2.st_dev
301     && s1.st_ino == s2.st_ino;
302     #endif
303    
304     if (success)
305     return h; // lock successfully acquired
306    
307     // files differ, close and retry - should be very rare
308     u_close (h);
309     }
310    
311     // failure
312     u_close (h);
313     return u_invalid_handle;
314     }
315