src/misc.c

   1 /* Copyright (c) 2008, 2009
   2  *      Juergen Weigert (jnweiger@immd4.informatik.uni-erlangen.de)
   3  *      Michael Schroeder (mlschroe@immd4.informatik.uni-erlangen.de)
   4  *      Micah Cowan (micah@cowan.name)
   5  *      Sadrul Habib Chowdhury (sadrul@users.sourceforge.net)
   6  * Copyright (c) 1993-2002, 2003, 2005, 2006, 2007
   7  *      Juergen Weigert (jnweiger@immd4.informatik.uni-erlangen.de)
   8  *      Michael Schroeder (mlschroe@immd4.informatik.uni-erlangen.de)
   9  * Copyright (c) 1987 Oliver Laumann
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 3, or (at your option)
  14  * any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program (see the file COPYING); if not, see
  23  * https://www.gnu.org/licenses/, or contact Free Software Foundation, Inc.,
  24  * 51 Franklin Street, Fifth Floor, Boston, MA  02111-1301  USA
  25  *
  26  ****************************************************************
  27  */
  28
  29 #include "config.h"
  30
  31 #include "misc.h"
  32
  33 #include <poll.h>
  34 #include <sys/types.h>
  35 #include <sys/stat.h>           /* mkdir() declaration */
  36 #include <signal.h>
  37 #include <stdint.h>
  38 #include <string.h>
  39 #include <stdbool.h>
  40
  41 #include "screen.h"
  42
  43 char *SaveStr(const char *str)
  44 {
  45         char *cp = strdup(str);
  46
  47         if (cp == NULL)
  48                 Panic(0, "%s", strnomem);
  49
  50         return cp;
  51 }
  52
  53 char *SaveStrn(const char *str, size_t n)
  54 {
  55         char *cp = strndup(str, n + 1);
  56
  57         if (cp == NULL)
  58                 Panic(0, "%s", strnomem);
  59
  60         return cp;
  61 }
  62
  63 void centerline(char *str, int y)
  64 {
  65         int l, n;
  66
  67         n = strlen(str);
  68         if (n > flayer->l_width - 1)
  69                 n = flayer->l_width - 1;
  70         l = (flayer->l_width - 1 - n) / 2;
  71         LPutStr(flayer, str, n, &mchar_blank, l, y);
  72 }
  73
  74 void leftline(char *str, int y, struct mchar *rend)
  75 {
  76         int l, n;
  77         struct mchar mchar_dol;
  78
  79         mchar_dol = mchar_blank;
  80         mchar_dol.image = '$';
  81
  82         l = n = strlen(str);
  83         if (n > flayer->l_width - 1)
  84                 n = flayer->l_width - 1;
  85         LPutStr(flayer, str, n, rend ? rend : &mchar_blank, 0, y);
  86         if (n != l)
  87                 LPutChar(flayer, &mchar_dol, n, y);
  88 }
  89
  90 char *Filename(char *s)
  91 {
  92         char *p = s;
  93
  94         if (p)
  95                 while (*p)
  96                         if (*p++ == '/')
  97                                 s = p;
  98         return s;
  99 }
 100
 101 char *stripdev(char *name)
 102 {
 103         if (name == NULL)
 104                 return NULL;
 105         if (strncmp(name, "/dev/", 5) == 0)
 106                 return name + 5;
 107         return name;
 108 }
 109
 110 /*
 111  *    Signal handling
 112  */
 113
 114 void (*xsignal(int sig, void (*func) (int))) (int) {
 115         struct sigaction osa, sa;
 116         sa.sa_handler = func;
 117         (void)sigemptyset(&sa.sa_mask);
 118 #ifdef SA_RESTART
 119         sa.sa_flags = (sig == SIGCHLD ? SA_RESTART : 0);
 120 #else
 121         sa.sa_flags = 0;
 122 #endif
 123         if (sigaction(sig, &sa, &osa))
 124                 return (void (*)(int))-1;
 125         return osa.sa_handler;
 126 }
 127
 128 /*
 129  *    uid/gid handling
 130  */
 131
 132 void xseteuid(int euid)
 133 {
 134         if (seteuid(euid) == 0)
 135                 return;
 136         if (seteuid(0) || seteuid(euid))
 137                 Panic(errno, "seteuid");
 138 }
 139
 140 void xsetegid(int egid)
 141 {
 142         if (setegid(egid))
 143                 Panic(errno, "setegid");
 144 }
 145
 146 void Kill(pid_t pid, int sig)
 147 {
 148         if (pid < 2)
 149                 return;
 150         (void)kill(pid, sig);
 151 }
 152
 153 void closeallfiles(int except)
 154 {
 155         struct pollfd pfd[1024];
 156         int maxfd, i, fd, ret, z;
 157
 158         i = 3; /* skip stdin, stdout and stderr */
 159         maxfd = getdtablesize();
 160
 161         while (i < maxfd) {
 162                 memset(pfd, 0, sizeof(pfd));
 163
 164                 z = 0;
 165                 for (fd = i; fd < maxfd && fd < i + 1024; fd++)
 166                         pfd[z++].fd = fd;
 167
 168                 ret = poll(pfd, fd - i, 0);
 169                 if (ret < 0)
 170                         Panic(errno, "poll");
 171
 172                 z = 0;
 173                 for (fd = i; fd < maxfd && fd < i + 1024; fd++)
 174                         if (!(pfd[z++].revents & POLLNVAL) && fd != except)
 175                                 close(fd);
 176
 177                 i = fd;
 178         }
 179 }
 180
 181 /*
 182  *  Security - switch to real uid
 183  */
 184
 185 static int UserSTAT;
 186
 187 int UserContext(void)
 188 {
 189         xseteuid(real_uid);
 190         xsetegid(real_gid);
 191         return 1;
 192 }
 193
 194 void UserReturn(int val)
 195 {
 196         xseteuid(eff_uid);
 197         xsetegid(eff_gid);
 198         UserSTAT = val;
 199 }
 200
 201 int UserStatus(void)
 202 {
 203         return UserSTAT;
 204 }
 205
 206 int AddXChar(char *buf, int ch)
 207 {
 208         char *p = buf;
 209
 210         if (ch < ' ' || ch == 0x7f) {
 211                 *p++ = '^';
 212                 *p++ = ch ^ 0x40;
 213         } else if (ch >= 0x80) {
 214                 *p++ = '\\';
 215                 *p++ = (ch >> 6 & 7) + '0';
 216                 *p++ = (ch >> 3 & 7) + '0';
 217                 *p++ = (ch >> 0 & 7) + '0';
 218         } else
 219                 *p++ = ch;
 220         return p - buf;
 221 }
 222
 223 int AddXChars(char *buf, int len, char *str)
 224 {
 225         char *p;
 226
 227         if (str == NULL) {
 228                 *buf = 0;
 229                 return 0;
 230         }
 231         len -= 4;               /* longest sequence produced by AddXChar() */
 232         for (p = buf; p < buf + len && *str; str++) {
 233                 if (*str == ' ')
 234                         *p++ = *str;
 235                 else
 236                         p += AddXChar(p, *str);
 237         }
 238         *p = 0;
 239         return p - buf;
 240 }