usr.sbin/pkg_install/lib/pen.c

   1 /*
   2  * FreeBSD install - a package for the installation and maintainance
   3  * of non-core utilities.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * Jordan K. Hubbard
  15  * 18 July 1993
  16  *
  17  * Routines for managing the "play pen".
  18  *
  19  */
  20
  21 #include <sys/cdefs.h>
  22 __FBSDID("$FreeBSD$");
  23
  24 #include "lib.h"
  25 #include <err.h>
  26 #include <libutil.h>
  27 #include <libgen.h>
  28 #include <sys/signal.h>
  29 #include <sys/param.h>
  30 #include <sys/mount.h>
  31
  32 /* For keeping track of where we are */
  33 static char PenLocation[FILENAME_MAX];
  34 static char Previous[FILENAME_MAX];
  35
  36 char *
  37 where_playpen(void)
  38 {
  39     return PenLocation;
  40 }
  41
  42 /* Find a good place to play. */
  43 static char *
  44 find_play_pen(char *pen, off_t sz)
  45 {
  46     char *cp;
  47     struct stat sb;
  48     char humbuf[6];
  49
  50     if (pen[0] && isdir(dirname(pen)) == TRUE && (min_free(dirname(pen)) >= sz))
  51         return pen;
  52     else if ((cp = getenv("PKG_TMPDIR")) != NULL && stat(cp, &sb) != FAIL && (min_free(cp) >= sz))
  53         sprintf(pen, "%s/instmp.XXXXXX", cp);
  54     else if ((cp = getenv("TMPDIR")) != NULL && stat(cp, &sb) != FAIL && (min_free(cp) >= sz))
  55         sprintf(pen, "%s/instmp.XXXXXX", cp);
  56     else if (stat("/var/tmp", &sb) != FAIL && min_free("/var/tmp") >= sz)
  57         strcpy(pen, "/var/tmp/instmp.XXXXXX");
  58     else if (stat("/tmp", &sb) != FAIL && min_free("/tmp") >= sz)
  59         strcpy(pen, "/tmp/instmp.XXXXXX");
  60     else if ((stat("/usr/tmp", &sb) == SUCCESS || mkdir("/usr/tmp", 01777) == SUCCESS) && min_free("/usr/tmp") >= sz)
  61         strcpy(pen, "/usr/tmp/instmp.XXXXXX");
  62     else {
  63         cleanup(0);
  64         humanize_number(humbuf, sizeof humbuf, sz, "", HN_AUTOSCALE,
  65             HN_NOSPACE);
  66         errx(2,
  67 "%s: can't find enough temporary space to extract the files, please set your\n"
  68 "PKG_TMPDIR environment variable to a location with at least %s bytes\n"
  69 "free", __func__, humbuf);
  70         return NULL;
  71     }
  72     return pen;
  73 }
  74
  75 #define MAX_STACK       20
  76 static char *pstack[MAX_STACK];
  77 static int pdepth = -1;
  78
  79 static void
  80 pushPen(const char *pen)
  81 {
  82     if (++pdepth == MAX_STACK)
  83         errx(2, "%s: stack overflow.\n", __func__);
  84     pstack[pdepth] = strdup(pen);
  85 }
  86
  87 static void
  88 popPen(char *pen)
  89 {
  90     if (pdepth == -1) {
  91         pen[0] = '\0';
  92         return;
  93     }
  94     strcpy(pen, pstack[pdepth]);
  95     free(pstack[pdepth--]);
  96 }
  97
  98 /*
  99  * Make a temporary directory to play in and chdir() to it, returning
 100  * pathname of previous working directory.
 101  */
 102 char *
 103 make_playpen(char *pen, off_t sz)
 104 {
 105     char humbuf1[6], humbuf2[6];
 106
 107     if (!find_play_pen(pen, sz))
 108         return NULL;
 109
 110     if (!mkdtemp(pen)) {
 111         cleanup(0);
 112         errx(2, "%s: can't mktemp '%s'", __func__, pen);
 113     }
 114     if (chmod(pen, 0700) == FAIL) {
 115         cleanup(0);
 116         errx(2, "%s: can't mkdir '%s'", __func__, pen);
 117     }
 118
 119     if (Verbose) {
 120         if (sz) {
 121             humanize_number(humbuf1, sizeof humbuf1, sz, "", HN_AUTOSCALE,
 122                 HN_NOSPACE);
 123             humanize_number(humbuf2, sizeof humbuf2, min_free(pen),
 124                 "", HN_AUTOSCALE, HN_NOSPACE);
 125             fprintf(stderr, "Requested space: %s bytes, free space: %s bytes in %s\n", humbuf1, humbuf2, pen);
 126         }
 127     }
 128
 129     if (min_free(pen) < sz) {
 130         rmdir(pen);
 131         cleanup(0);
 132         errx(2, "%s: not enough free space to create '%s'.\n"
 133              "Please set your PKG_TMPDIR environment variable to a location\n"
 134              "with more space and\ntry the command again", __func__, pen);
 135     }
 136
 137     if (!getcwd(Previous, FILENAME_MAX)) {
 138         upchuck("getcwd");
 139         return NULL;
 140     }
 141
 142     if (chdir(pen) == FAIL) {
 143         cleanup(0);
 144         errx(2, "%s: can't chdir to '%s'", __func__, pen);
 145     }
 146
 147     if (PenLocation[0])
 148         pushPen(PenLocation);
 149
 150     strcpy(PenLocation, pen);
 151     return Previous;
 152 }
 153
 154 /* Convenience routine for getting out of playpen */
 155 void
 156 leave_playpen()
 157 {
 158     void (*oldsig)(int);
 159
 160     /* Don't interrupt while we're cleaning up */
 161     oldsig = signal(SIGINT, SIG_IGN);
 162     if (Previous[0]) {
 163         if (chdir(Previous) == FAIL) {
 164             cleanup(0);
 165             errx(2, "%s: can't chdir back to '%s'", __func__, Previous);
 166         }
 167         Previous[0] = '\0';
 168     }
 169     if (PenLocation[0]) {
 170         if (PenLocation[0] == '/' && vsystem("/bin/rm -rf %s", PenLocation))
 171             warnx("couldn't remove temporary dir '%s'", PenLocation);
 172         popPen(PenLocation);
 173     }
 174     signal(SIGINT, oldsig);
 175 }
 176
 177 off_t
 178 min_free(const char *tmpdir)
 179 {
 180     struct statfs buf;
 181
 182     if (statfs(tmpdir, &buf) != 0) {
 183         warn("statfs");
 184         return -1;
 185     }
 186     return (off_t)buf.f_bavail * (off_t)buf.f_bsize;
 187 }