1 /* Generate an index to speed access to archives.
2    Copyright (C) 2005-2012 Red Hat, Inc.
3    This file is part of elfutils.
4    Written by Ulrich Drepper <drepper@redhat.com>, 2005.
5 
6    This file is free software; you can redistribute it and/or modify
7    it under the terms of the GNU General Public License as published by
8    the Free Software Foundation; either version 3 of the License, or
9    (at your option) any later version.
10 
11    elfutils is distributed in the hope that it will be useful, but
12    WITHOUT ANY WARRANTY; without even the implied warranty of
13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14    GNU General Public License for more details.
15 
16    You should have received a copy of the GNU General Public License
17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
18 
19 #ifdef HAVE_CONFIG_H
20 # include <config.h>
21 #endif
22 
23 #include <ar.h>
24 #include <argp.h>
25 #include <assert.h>
26 #include <errno.h>
27 #include <error.h>
28 #include <fcntl.h>
29 #include <gelf.h>
30 #include <libintl.h>
31 #include <locale.h>
32 #include <mcheck.h>
33 #include <obstack.h>
34 #include <stdlib.h>
35 #include <stdio.h>
36 #include <stdio_ext.h>
37 #include <unistd.h>
38 #include <sys/mman.h>
39 #include <sys/param.h>
40 #include <sys/stat.h>
41 
42 #include <system.h>
43 
44 #include "arlib.h"
45 
46 
47 /* Prototypes for local functions.  */
48 static int handle_file (const char *fname);
49 
50 
51 /* Name and version of program.  */
52 static void print_version (FILE *stream, struct argp_state *state);
53 ARGP_PROGRAM_VERSION_HOOK_DEF = print_version;
54 
55 /* Bug report address.  */
56 ARGP_PROGRAM_BUG_ADDRESS_DEF = PACKAGE_BUGREPORT;
57 
58 
59 /* Definitions of arguments for argp functions.  */
60 static const struct argp_option options[] =
61 {
62   { NULL, 0, NULL, 0, NULL, 0 }
63 };
64 
65 /* Short description of program.  */
66 static const char doc[] = N_("Generate an index to speed access to archives.");
67 
68 /* Strings for arguments in help texts.  */
69 static const char args_doc[] = N_("ARCHIVE");
70 
71 /* Data structure to communicate with argp functions.  */
72 static const struct argp argp =
73 {
74   options, NULL, args_doc, doc, arlib_argp_children, NULL, NULL
75 };
76 
77 
78 int
main(int argc,char * argv[])79 main (int argc, char *argv[])
80 {
81   /* Make memory leak detection possible.  */
82   mtrace ();
83 
84   /* We use no threads here which can interfere with handling a stream.  */
85   (void) __fsetlocking (stdin, FSETLOCKING_BYCALLER);
86   (void) __fsetlocking (stdout, FSETLOCKING_BYCALLER);
87   (void) __fsetlocking (stderr, FSETLOCKING_BYCALLER);
88 
89   /* Set locale.  */
90   (void) setlocale (LC_ALL, "");
91 
92   /* Make sure the message catalog can be found.  */
93   (void) bindtextdomain (PACKAGE_TARNAME, LOCALEDIR);
94 
95   /* Initialize the message catalog.  */
96   (void) textdomain (PACKAGE_TARNAME);
97 
98   /* Parse and process arguments.  */
99   int remaining;
100   (void) argp_parse (&argp, argc, argv, ARGP_IN_ORDER, &remaining, NULL);
101 
102   /* Tell the library which version we are expecting.  */
103   (void) elf_version (EV_CURRENT);
104 
105   /* There must at least be one more parameter specifying the archive.   */
106   if (remaining == argc)
107     {
108       error (0, 0, gettext ("Archive name required"));
109       argp_help (&argp, stderr, ARGP_HELP_SEE, "ranlib");
110       exit (EXIT_FAILURE);
111     }
112 
113   /* We accept the names of multiple archives.  */
114   int status = 0;
115   do
116     status |= handle_file (argv[remaining]);
117   while (++remaining < argc);
118 
119   return status;
120 }
121 
122 
123 /* Print the version information.  */
124 static void
print_version(FILE * stream,struct argp_state * state)125 print_version (FILE *stream, struct argp_state *state __attribute__ ((unused)))
126 {
127   fprintf (stream, "ranlib (%s) %s\n", PACKAGE_NAME, PACKAGE_VERSION);
128   fprintf (stream, gettext ("\
129 Copyright (C) %s Red Hat, Inc.\n\
130 This is free software; see the source for copying conditions.  There is NO\n\
131 warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
132 "), "2012");
133   fprintf (stream, gettext ("Written by %s.\n"), "Ulrich Drepper");
134 }
135 
136 
137 static int
copy_content(Elf * elf,int newfd,off_t off,size_t n)138 copy_content (Elf *elf, int newfd, off_t off, size_t n)
139 {
140   size_t len;
141   char *rawfile = elf_rawfile (elf, &len);
142 
143   assert (off + n <= len);
144 
145   /* Tell the kernel we will read all the pages sequentially.  */
146   size_t ps = sysconf (_SC_PAGESIZE);
147   if (n > 2 * ps)
148     posix_madvise (rawfile + (off & ~(ps - 1)), n, POSIX_MADV_SEQUENTIAL);
149 
150   return write_retry (newfd, rawfile + off, n) != (ssize_t) n;
151 }
152 
153 
154 /* Handle a file given on the command line.  */
155 static int
handle_file(const char * fname)156 handle_file (const char *fname)
157 {
158   int fd = open (fname, O_RDONLY);
159   if (fd == -1)
160     {
161       error (0, errno, gettext ("cannot open '%s'"), fname);
162       return 1;
163     }
164 
165   struct stat st;
166   if (fstat (fd, &st) != 0)
167     {
168       error (0, errno, gettext ("cannot stat '%s'"), fname);
169       close (fd);
170       return 1;
171     }
172 
173   /* First we walk through the file, looking for all ELF files to
174      collect symbols from.  */
175   Elf *arelf = elf_begin (fd, ELF_C_READ_MMAP, NULL);
176   if (arelf == NULL)
177     {
178       error (0, 0, gettext ("cannot create ELF descriptor for '%s': %s"),
179 	     fname, elf_errmsg (-1));
180       close (fd);
181       return 1;
182     }
183 
184   if (elf_kind (arelf) != ELF_K_AR)
185     {
186       error (0, 0, gettext ("'%s' is no archive"), fname);
187       elf_end (arelf);
188       close (fd);
189       return 1;
190     }
191 
192   arlib_init ();
193 
194   /* Iterate over the content of the archive.  */
195   off_t index_off = -1;
196   size_t index_size = 0;
197   off_t cur_off = SARMAG;
198   Elf *elf;
199   Elf_Cmd cmd = ELF_C_READ_MMAP;
200   while ((elf = elf_begin (fd, cmd, arelf)) != NULL)
201     {
202       Elf_Arhdr *arhdr = elf_getarhdr (elf);
203       assert (arhdr != NULL);
204 
205       /* If this is the index, remember the location.  */
206       if (strcmp (arhdr->ar_name, "/") == 0)
207 	{
208 	  index_off = elf_getaroff (elf);
209 	  index_size = arhdr->ar_size;
210 	}
211       else
212 	{
213 	  arlib_add_symbols (elf, fname, arhdr->ar_name, cur_off);
214 	  cur_off += (((arhdr->ar_size + 1) & ~((off_t) 1))
215 		      + sizeof (struct ar_hdr));
216 	}
217 
218       /* Get next archive element.  */
219       cmd = elf_next (elf);
220       if (elf_end (elf) != 0)
221 	error (0, 0, gettext ("error while freeing sub-ELF descriptor: %s"),
222 	       elf_errmsg (-1));
223     }
224 
225   arlib_finalize ();
226 
227   /* If the file contains no symbols we need not do anything.  */
228   int status = 0;
229   if (symtab.symsnamelen != 0
230       /* We have to rewrite the file also if it initially had an index
231 	 but now does not need one anymore.  */
232       || (symtab.symsnamelen == 0 && index_size != 0))
233     {
234       /* Create a new, temporary file in the same directory as the
235 	 original file.  */
236       char tmpfname[strlen (fname) + 7];
237       strcpy (stpcpy (tmpfname, fname), "XXXXXX");
238       int newfd = mkstemp (tmpfname);
239       if (unlikely (newfd == -1))
240 	{
241 	nonew:
242 	  error (0, errno, gettext ("cannot create new file"));
243 	  status = 1;
244 	}
245       else
246 	{
247 	  /* Create the header.  */
248 	  if (unlikely (write_retry (newfd, ARMAG, SARMAG) != SARMAG))
249 	    {
250 	      // XXX Use /prof/self/fd/%d ???
251 	    nonew_unlink:
252 	      unlink (tmpfname);
253 	      if (newfd != -1)
254 		close (newfd);
255 	      goto nonew;
256 	    }
257 
258 	  /* Create the new file.  There are three parts as far we are
259 	     concerned: 1. original context before the index, 2. the
260 	     new index, 3. everything after the new index.  */
261 	  off_t rest_off;
262 	  if (index_off != -1)
263 	    rest_off = (index_off + sizeof (struct ar_hdr)
264 			+ ((index_size + 1) & ~1ul));
265 	  else
266 	    rest_off = SARMAG;
267 
268 	  if ((symtab.symsnamelen != 0
269 	       && ((write_retry (newfd, symtab.symsoff,
270 				 symtab.symsofflen)
271 		    != (ssize_t) symtab.symsofflen)
272 		   || (write_retry (newfd, symtab.symsname,
273 				    symtab.symsnamelen)
274 		       != (ssize_t) symtab.symsnamelen)))
275 	      /* Even if the original file had content before the
276 		 symbol table, we write it in the correct order.  */
277 	      || (index_off > SARMAG
278 		  && copy_content (arelf, newfd, SARMAG, index_off - SARMAG))
279 	      || copy_content (arelf, newfd, rest_off, st.st_size - rest_off)
280 	      /* Set the mode of the new file to the same values the
281 		 original file has.  */
282 	      || fchmod (newfd, st.st_mode & ALLPERMS) != 0
283 	      /* Never complain about fchown failing.  */
284 	      || (({asm ("" :: "r" (fchown (newfd, st.st_uid, st.st_gid))); }),
285 		  close (newfd) != 0)
286 	      || (newfd = -1, rename (tmpfname, fname) != 0))
287 	    goto nonew_unlink;
288 	}
289     }
290 
291   elf_end (arelf);
292 
293   arlib_fini ();
294 
295   close (fd);
296 
297   return status;
298 }
299 
300 
301 #include "debugpred.h"
302