dselect/methparse.cc

   1 /*
   2  * dselect - Debian package maintenance user interface
   3  * methparse.cc - access method list parsing
   4  *
   5  * Copyright © 1995 Ian Jackson <ijackson@chiark.greenend.org.uk>
   6  * Copyright © 2008-2011, 2013-2015 Guillem Jover <guillem@debian.org>
   7  *
   8  * This is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  20  */
  21
  22 #include <config.h>
  23 #include <compat.h>
  24
  25 #include <sys/types.h>
  26 #include <sys/stat.h>
  27 #include <sys/wait.h>
  28
  29 #include <errno.h>
  30 #include <limits.h>
  31 #include <string.h>
  32 #include <dirent.h>
  33 #include <unistd.h>
  34 #include <stdlib.h>
  35 #include <stdio.h>
  36
  37 #include <dpkg/i18n.h>
  38 #include <dpkg/c-ctype.h>
  39 #include <dpkg/dpkg.h>
  40 #include <dpkg/dpkg-db.h>
  41
  42 #include "dselect.h"
  43 #include "bindings.h"
  44 #include "method.h"
  45
  46 int noptions=0;
  47 struct dselect_option *options = nullptr, *coption = nullptr;
  48 struct method *methods = nullptr;
  49
  50 static void DPKG_ATTR_NORET
  51 badmethod(const char *pathname, const char *why)
  52 {
  53   ohshit(_("syntax error in method options file '%.250s' -- %s"), pathname, why);
  54 }
  55
  56 static void DPKG_ATTR_NORET
  57 eofmethod(const char *pathname, FILE *f, const char *why)
  58 {
  59   if (ferror(f))
  60     ohshite(_("error reading options file '%.250s'"), pathname);
  61   badmethod(pathname,why);
  62 }
  63
  64 void readmethods(const char *pathbase, dselect_option **optionspp, int *nread) {
  65   static const char *const methodprograms[]= {
  66     METHODSETUPSCRIPT,
  67     METHODUPDATESCRIPT,
  68     METHODINSTALLSCRIPT,
  69     nullptr
  70   };
  71   const char *const *ccpp;
  72   int methodlen, baselen;
  73   char *pathinmeth, *pathbuf, *pathmeth;
  74   DIR *dir;
  75   FILE *names, *descfile;
  76   struct dirent *dent;
  77   struct varbuf vb;
  78   method *meth;
  79   dselect_option *opt;
  80   struct stat stab;
  81
  82   baselen= strlen(pathbase);
  83   pathbuf= new char[baselen+IMETHODMAXLEN+IOPTIONMAXLEN+sizeof(OPTIONSDESCPFX)+10];
  84   strcpy(pathbuf,pathbase);
  85   strcpy(pathbuf+baselen,"/");
  86   pathmeth= pathbuf+baselen+1;
  87
  88   dir= opendir(pathbuf);
  89   if (!dir) {
  90     if (errno == ENOENT) {
  91       delete[] pathbuf;
  92       return;
  93     }
  94     ohshite(_("unable to read '%.250s' directory for reading methods"),
  95             pathbuf);
  96   }
  97
  98   debug(dbg_general, "readmethods('%s',...) directory open", pathbase);
  99
 100   while ((dent = readdir(dir)) != nullptr) {
 101     int c = dent->d_name[0];
 102     debug(dbg_general, "readmethods('%s',...) considering '%s' ...",
 103           pathbase, dent->d_name);
 104     if (c != '_' && !c_isalpha(c))
 105       continue;
 106     char *p = dent->d_name + 1;
 107     while ((c = *p) != 0 && c_isalnum(c) && c != '_')
 108       p++;
 109     if (c) continue;
 110     methodlen= strlen(dent->d_name);
 111     if (methodlen > IMETHODMAXLEN)
 112       ohshit(_("method '%.250s' has name that is too long (%d > %d characters)"),
 113              dent->d_name, methodlen, IMETHODMAXLEN);
 114     /* Check if there is a localized version of this method */
 115
 116     strcpy(pathmeth, dent->d_name);
 117     strcpy(pathmeth+methodlen, "/");
 118     pathinmeth= pathmeth+methodlen+1;
 119
 120     for (ccpp= methodprograms; *ccpp; ccpp++) {
 121       strcpy(pathinmeth,*ccpp);
 122       if (access(pathbuf,R_OK|X_OK))
 123         ohshite(_("unable to access method script '%.250s'"), pathbuf);
 124     }
 125     debug(dbg_general, " readmethods('%s',...) scripts ok", pathbase);
 126
 127     strcpy(pathinmeth,METHODOPTIONSFILE);
 128     names= fopen(pathbuf,"r");
 129     if (!names)
 130       ohshite(_("unable to read method options file '%.250s'"), pathbuf);
 131
 132     meth= new method;
 133     meth->name= new char[strlen(dent->d_name)+1];
 134     strcpy(meth->name,dent->d_name);
 135     meth->path= new char[baselen+1+methodlen+2+50];
 136     strncpy(meth->path,pathbuf,baselen+1+methodlen);
 137     strcpy(meth->path+baselen+1+methodlen,"/");
 138     meth->pathinmeth= meth->path+baselen+1+methodlen+1;
 139     meth->next= methods;
 140     meth->prev = nullptr;
 141     if (methods)
 142       methods->prev = meth;
 143     methods= meth;
 144     debug(dbg_general, " readmethods('%s',...) new method"
 145                        " name='%s' path='%s' pathinmeth='%s'",
 146           pathbase, meth->name, meth->path, meth->pathinmeth);
 147
 148     while ((c= fgetc(names)) != EOF) {
 149       if (c_isspace(c))
 150         continue;
 151       opt= new dselect_option;
 152       opt->meth= meth;
 153       vb.reset();
 154       do {
 155         if (!c_isdigit(c))
 156           badmethod(pathbuf, _("non-digit where digit wanted"));
 157         vb(c);
 158         c= fgetc(names);
 159         if (c == EOF)
 160           eofmethod(pathbuf, names, _("end of file in index string"));
 161       } while (!c_isspace(c));
 162       if (strlen(vb.string()) > OPTIONINDEXMAXLEN)
 163         badmethod(pathbuf,_("index string too long"));
 164       strcpy(opt->index,vb.string());
 165       do {
 166         if (c == '\n') badmethod(pathbuf,_("newline before option name start"));
 167         c= fgetc(names);
 168         if (c == EOF)
 169           eofmethod(pathbuf, names, _("end of file before option name start"));
 170       } while (c_isspace(c));
 171       vb.reset();
 172       if (!c_isalpha(c) && c != '_')
 173         badmethod(pathbuf,_("nonalpha where option name start wanted"));
 174       do {
 175         if (!c_isalnum(c) && c != '_')
 176           badmethod(pathbuf, _("non-alphanum in option name"));
 177         vb(c);
 178         c= fgetc(names);
 179         if (c == EOF)
 180           eofmethod(pathbuf, names, _("end of file in option name"));
 181       } while (!c_isspace(c));
 182       opt->name= new char[strlen(vb.string())+1];
 183       strcpy(opt->name,vb.string());
 184       do {
 185         if (c == '\n') badmethod(pathbuf,_("newline before summary"));
 186         c= fgetc(names);
 187         if (c == EOF)
 188           eofmethod(pathbuf, names, _("end of file before summary"));
 189       } while (c_isspace(c));
 190       vb.reset();
 191       do {
 192         vb(c);
 193         c= fgetc(names);
 194         if (c == EOF)
 195           eofmethod(pathbuf, names, _("end of file in summary - missing newline"));
 196       } while (c != '\n');
 197       opt->summary= new char[strlen(vb.string())+1];
 198       strcpy(opt->summary,vb.string());
 199
 200       strcpy(pathinmeth,OPTIONSDESCPFX);
 201       strcpy(pathinmeth+sizeof(OPTIONSDESCPFX)-1,opt->name);
 202       descfile= fopen(pathbuf,"r");
 203       if (!descfile) {
 204         if (errno != ENOENT)
 205           ohshite(_("unable to open option description file '%.250s'"), pathbuf);
 206         opt->description = nullptr;
 207       } else { /* descfile != 0 */
 208         if (fstat(fileno(descfile),&stab))
 209           ohshite(_("unable to stat option description file '%.250s'"), pathbuf);
 210         opt->description= new char[stab.st_size+1];  errno=0;
 211         size_t filelen = stab.st_size;
 212         if (fread(opt->description,1,stab.st_size+1,descfile) != filelen)
 213           ohshite(_("failed to read option description file '%.250s'"), pathbuf);
 214         opt->description[stab.st_size]= 0;
 215         if (ferror(descfile))
 216           ohshite(_("error during read of option description file '%.250s'"), pathbuf);
 217         fclose(descfile);
 218       }
 219       strcpy(pathinmeth,METHODOPTIONSFILE);
 220
 221       debug(dbg_general,
 222             " readmethods('%s',...) new option index='%s' name='%s'"
 223             " summary='%.20s' strlen(description=%s)=%zu method name='%s'"
 224             " path='%s' pathinmeth='%s'",
 225             pathbase,
 226             opt->index, opt->name, opt->summary,
 227             opt->description ? "'...'" : "null",
 228             opt->description ? strlen(opt->description) : -1,
 229             opt->meth->name, opt->meth->path, opt->meth->pathinmeth);
 230
 231       dselect_option **optinsert = optionspp;
 232       while (*optinsert && strcmp(opt->index, (*optinsert)->index) > 0)
 233         optinsert = &(*optinsert)->next;
 234       opt->next= *optinsert;
 235       *optinsert= opt;
 236       (*nread)++;
 237     }
 238     if (ferror(names))
 239       ohshite(_("error during read of method options file '%.250s'"), pathbuf);
 240     fclose(names);
 241   }
 242   closedir(dir);
 243   debug(dbg_general, "readmethods('%s',...) done", pathbase);
 244   delete[] pathbuf;
 245 }
 246
 247 static char *methoptfile = nullptr;
 248
 249 void getcurrentopt() {
 250   char methoptbuf[IMETHODMAXLEN+1+IOPTIONMAXLEN+2];
 251   FILE *cmo;
 252   int l;
 253   char *p;
 254
 255   if (methoptfile == nullptr)
 256     methoptfile = dpkg_db_get_path(CMETHOPTFILE);
 257
 258   coption = nullptr;
 259   cmo= fopen(methoptfile,"r");
 260   if (!cmo) {
 261     if (errno == ENOENT) return;
 262     ohshite(_("unable to open current option file '%.250s'"), methoptfile);
 263   }
 264   debug(dbg_general, "getcurrentopt() cmethopt open");
 265   if (!fgets(methoptbuf,sizeof(methoptbuf),cmo)) { fclose(cmo); return; }
 266   if (fgetc(cmo) != EOF) { fclose(cmo); return; }
 267   if (!feof(cmo)) { fclose(cmo); return; }
 268   debug(dbg_general, "getcurrentopt() cmethopt eof");
 269   fclose(cmo);
 270   debug(dbg_general, "getcurrentopt() cmethopt read");
 271   l= strlen(methoptbuf);  if (!l || methoptbuf[l-1] != '\n') return;
 272   methoptbuf[--l]= 0;
 273   debug(dbg_general, "getcurrentopt() cmethopt len and newline");
 274   p= strchr(methoptbuf,' ');  if (!p) return;
 275   debug(dbg_general, "getcurrentopt() cmethopt space");
 276   *p++= 0;
 277   debug(dbg_general, "getcurrentopt() cmethopt meth name '%s'", methoptbuf);
 278   method *meth = methods;
 279   while (meth && strcmp(methoptbuf, meth->name))
 280     meth = meth->next;
 281   if (!meth) return;
 282   debug(dbg_general, "getcurrentopt() cmethopt meth found; opt '%s'", p);
 283   dselect_option *opt = options;
 284   while (opt && (opt->meth != meth || strcmp(p, opt->name)))
 285     opt = opt->next;
 286   if (!opt) return;
 287   debug(dbg_general, "getcurrentopt() cmethopt opt found");
 288   coption= opt;
 289 }
 290
 291 void writecurrentopt() {
 292   struct atomic_file *file;
 293
 294   if (methoptfile == nullptr)
 295     internerr("method options filename is nullptr");
 296
 297   file = atomic_file_new(methoptfile, ATOMIC_FILE_NORMAL);
 298   atomic_file_open(file);
 299   if (fprintf(file->fp, "%s %s\n", coption->meth->name, coption->name) == EOF)
 300     ohshite(_("unable to write new option to '%.250s'"), file->name_new);
 301   atomic_file_close(file);
 302   atomic_file_commit(file);
 303   atomic_file_free(file);
 304 }