dselect/method.cc

   1 /*
   2  * dselect - Debian package maintenance user interface
   3  * method.cc - access method handling
   4  *
   5  * Copyright © 1995 Ian Jackson <ijackson@chiark.greenend.org.uk>
   6  * Copyright © 2001,2002 Wichert Akkerman <wakkerma@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/file.h>
  28 #include <sys/wait.h>
  29
  30 #include <errno.h>
  31 #include <limits.h>
  32 #include <string.h>
  33 #include <fcntl.h>
  34 #include <dirent.h>
  35 #include <signal.h>
  36 #include <unistd.h>
  37 #include <stdlib.h>
  38 #include <stdio.h>
  39
  40 #include <dpkg/i18n.h>
  41 #include <dpkg/dpkg.h>
  42 #include <dpkg/dpkg-db.h>
  43 #include <dpkg/subproc.h>
  44 #include <dpkg/command.h>
  45
  46 #include "dselect.h"
  47 #include "method.h"
  48
  49 static const char *const methoddirectories[]= {
  50   LIBDIR "/" METHODSDIR,
  51   LOCALLIBDIR "/" METHODSDIR,
  52   nullptr
  53 };
  54
  55 static char *methodlockfile = nullptr;
  56 static int methlockfd= -1;
  57
  58 static void
  59 sthfailed(const char * reasoning)
  60 {
  61   curseson();
  62   clear();
  63   printw("\n\n%s: %s\n", DSELECT, reasoning);
  64   attrset(A_BOLD);
  65   addstr(_("\nPress <enter> to continue."));
  66   attrset(A_NORMAL);
  67   refresh(); getch();
  68 }
  69
  70 static void cu_unlockmethod(int, void**) {
  71   struct flock fl;
  72
  73   if (methodlockfile == nullptr)
  74     internerr("method lock file is nullptr");
  75   if (methlockfd < 0)
  76     internerr("method lock fd is %d < 0", methlockfd);
  77   fl.l_type=F_UNLCK; fl.l_whence= SEEK_SET; fl.l_start=fl.l_len=0;
  78   if (fcntl(methlockfd,F_SETLK,&fl) == -1)
  79     sthfailed(_("cannot unlock access method area"));
  80 }
  81
  82 static enum urqresult ensureoptions(void) {
  83   dselect_option *newoptions;
  84   int nread;
  85
  86   if (!options) {
  87     newoptions = nullptr;
  88     nread= 0;
  89     for (const char *const *ccpp = methoddirectories; *ccpp; ccpp++)
  90       readmethods(*ccpp, &newoptions, &nread);
  91     if (!newoptions) {
  92       sthfailed(_("no access methods are available"));
  93       return urqr_fail;
  94     }
  95     options= newoptions;
  96     noptions= nread;
  97   }
  98   return urqr_normal;
  99 }
 100
 101 static enum urqresult lockmethod(void) {
 102   struct flock fl;
 103
 104   if (methodlockfile == nullptr)
 105     methodlockfile = dpkg_db_get_path(METHLOCKFILE);
 106
 107   if (methlockfd == -1) {
 108     methlockfd= open(methodlockfile, O_RDWR|O_CREAT|O_TRUNC, 0660);
 109     if (methlockfd == -1) {
 110       if ((errno == EPERM) || (errno == EACCES)) {
 111         sthfailed(_("requested operation requires superuser privilege"));
 112         return urqr_fail;
 113       }
 114       sthfailed(_("cannot open or create access method lockfile"));
 115       return urqr_fail;
 116     }
 117   }
 118   fl.l_type=F_WRLCK; fl.l_whence=SEEK_SET; fl.l_start=fl.l_len=0;
 119   if (fcntl(methlockfd,F_SETLK,&fl) == -1) {
 120     if (errno == EACCES || errno == EAGAIN) {
 121       sthfailed(_("the access method area is already locked"));
 122       return urqr_fail;
 123     }
 124     sthfailed(_("cannot lock access method area"));
 125     return urqr_fail;
 126   }
 127   push_cleanup(cu_unlockmethod, ~0, 0);
 128   return urqr_normal;
 129 }
 130
 131 static urqresult
 132 falliblesubprocess(struct command *cmd)
 133 {
 134   pid_t pid;
 135   int i, c;
 136
 137   cursesoff();
 138
 139   subproc_signals_ignore(cmd->name);
 140
 141   pid = subproc_fork();
 142   if (pid == 0) {
 143     subproc_signals_cleanup(0, nullptr);
 144     command_exec(cmd);
 145   }
 146
 147   fprintf(stderr, "\n");
 148
 149   i = subproc_reap(pid, cmd->name, SUBPROC_WARN);
 150
 151   subproc_signals_restore();
 152
 153   if (i == 0) {
 154     sleep(1);
 155     return urqr_normal;
 156   }
 157   fprintf(stderr,_("Press <enter> to continue.\n"));
 158   m_output(stderr, _("<standard error>"));
 159   do {
 160     c = fgetc(stdin);
 161   } while ((c == EOF && errno == EINTR) || (c != '\n' && c != EOF));
 162   if (c == EOF)
 163     ohshite(_("error reading acknowledgement of program failure message"));
 164   return urqr_fail;
 165 }
 166
 167 static urqresult runscript(const char *exepath, const char *name) {
 168   urqresult ur;
 169
 170   ur= ensureoptions();  if (ur != urqr_normal) return ur;
 171   ur=lockmethod();  if (ur != urqr_normal) return ur;
 172   getcurrentopt();
 173
 174   if (coption) {
 175     struct command cmd;
 176
 177     strcpy(coption->meth->pathinmeth,exepath);
 178
 179     command_init(&cmd, coption->meth->path, name);
 180     command_add_args(&cmd, exepath, dpkg_db_get_dir(),
 181                      coption->meth->name, coption->name, nullptr);
 182     ur = falliblesubprocess(&cmd);
 183     command_destroy(&cmd);
 184   } else {
 185     sthfailed(_("no access method is selected or configured"));
 186     ur= urqr_fail;
 187   }
 188   pop_cleanup(ehflag_normaltidy);
 189
 190   return ur;
 191 }
 192
 193 urqresult urq_update(void) {
 194   return runscript(METHODUPDATESCRIPT,_("update available list script"));
 195 }
 196
 197 urqresult urq_install(void) {
 198   return runscript(METHODINSTALLSCRIPT,_("installation script"));
 199 }
 200
 201 static urqresult rundpkgauto(const char *name, const char *dpkgmode) {
 202   urqresult ur;
 203   struct command cmd;
 204
 205   command_init(&cmd, DPKG, name);
 206   command_add_args(&cmd, DPKG, "--admindir", dpkg_db_get_dir(), "--pending",
 207                    dpkgmode, nullptr);
 208
 209   cursesoff();
 210   printf(_("running %s %s ...\n"), "dpkg --pending", dpkgmode);
 211   fflush(stdout);
 212   ur = falliblesubprocess(&cmd);
 213   command_destroy(&cmd);
 214
 215   return ur;
 216 }
 217
 218 urqresult urq_remove(void) {
 219   return rundpkgauto("dpkg --remove","--remove");
 220 }
 221
 222 urqresult urq_config(void) {
 223   return rundpkgauto("dpkg --configure","--configure");
 224 }
 225
 226 urqresult urq_setup(void) {
 227   quitaction qa;
 228   urqresult ur;
 229
 230   ur= ensureoptions();  if (ur != urqr_normal) return ur;
 231   ur=lockmethod();  if (ur != urqr_normal) return ur;
 232   getcurrentopt();
 233
 234   curseson();
 235   methodlist *l= new methodlist();
 236   qa= l->display();
 237   delete l;
 238
 239   if (qa == qa_quitchecksave) {
 240     struct command cmd;
 241
 242     strcpy(coption->meth->pathinmeth,METHODSETUPSCRIPT);
 243
 244     command_init(&cmd, coption->meth->path, _("query/setup script"));
 245     command_add_args(&cmd, METHODSETUPSCRIPT, dpkg_db_get_dir(),
 246                      coption->meth->name, coption->name, nullptr);
 247     ur = falliblesubprocess(&cmd);
 248     command_destroy(&cmd);
 249     if (ur == urqr_normal) writecurrentopt();
 250   } else {
 251     ur= urqr_fail;
 252   }
 253
 254   pop_cleanup(ehflag_normaltidy);
 255   return ur;
 256 }