contrib/kill.c

   1 /*
   2     Copyright (C) 2001-2011 Ben Kibbey <bjk@luxsci.net>
   3
   4     This program is free software; you can redistribute it and/or modify
   5     it under the terms of the GNU General Public License as published by
   6     the Free Software Foundation; either version 2 of the License, or
   7     (at your option) any later version.
   8
   9     This program is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12     GNU General Public License for more details.
  13
  14     You should have received a copy of the GNU General Public License
  15     along with this program; if not, write to the Free Software
  16     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02110-1301  USA
  17 */
  18 /*
  19  *
  20  * Try and kill off a users login process(s). This needs the userinfo utility
  21  * from http://userinfo.sourceforge.net/ with the login.so module loaded
  22  * and chained (-x) before this module.
  23  *
  24  * Compile with:
  25  *     gcc -O2 -g -Wall -shared -fPIC -o kill.so kill.c
  26  *
  27  * Run with:
  28  *     ui -x login.so -p -- -O ./kill.so --
  29  *
  30  * Or with any other options you'd want. Just make sure the first option to
  31  * the login module is -p.
  32  *
  33  * Ben Kibbey <bjk@luxsci.net>
  34  */
  35 #include <stdio.h>
  36 #include <stdlib.h>
  37 #include <pwd.h>
  38 #include <sys/types.h>
  39 #include <signal.h>
  40 #include <string.h>
  41 #include <ctype.h>
  42 #include <getopt.h>
  43 #include <err.h>
  44 #include <limits.h>
  45
  46 #define KILL_OPTION_STRING      "s:"
  47
  48 void add_string(char ***, char *);
  49
  50 static int *do_sigs;
  51 static int sig_index;
  52
  53 struct signals {
  54     int sig;
  55     char *name;
  56 };
  57
  58 static struct signals sigs[] = {
  59     {1, "SIGHUP"},
  60     {2, "SIGINT"},
  61     {3, "SIGQUIT"},
  62     {4, "SIGILL"},
  63     {6, "SIGABRT"},
  64     {8, "SIGFPE"},
  65     {9, "SIGKILL"},
  66     {11, "SIGSEGV"},
  67     {13, "SIGPIPE"},
  68     {14, "SIGALRM"},
  69     {15, "SIGTERM"},
  70 #ifdef __i386__
  71     /* or PPC */
  72     {10, "SIGUSR1"},
  73     {12, "SIGUSR2"},
  74     {17, "SIGCHLD"},
  75     {18, "SIGCONT"},
  76     {19, "SIGSTOP"},
  77     {20, "SIGTSTP"},
  78     {21, "SIGTTIN"},
  79     {22, "SIGTTOU"},
  80 #else
  81     /* Alpha or SPARC. */
  82     {30, "SIGUSR1"},
  83     {31, "SIGUSR2"},
  84     {20, "SIGCHLD"},
  85     {19, "SIGCONT"},
  86     {17, "SIGSTOP"},
  87     {18, "SIGTSTP"},
  88     {21, "SIGTTIN"},
  89     {22, "SIGTTOU"},
  90 #endif
  91     {-1, NULL}
  92 };
  93
  94 void ui_module_init(int *chainable)
  95 {
  96     do_sigs = realloc(do_sigs, (sig_index + 2) * sizeof(int *));
  97     do_sigs[sig_index++] = 1;
  98     do_sigs = realloc(do_sigs, (sig_index + 2) * sizeof(int *));
  99     do_sigs[sig_index++] = 9;
 100     *chainable = 1;
 101     return;
 102 }
 103
 104 void ui_module_exit()
 105 {
 106     if (do_sigs)
 107         free(do_sigs);
 108
 109     return;
 110 }
 111
 112 void ui_module_help()
 113 {
 114     printf("  Kill a login process; requires login.so -p (-s SIGHUP,9):\n");
 115     printf("\t-s  Send these comma separated signals (integers or strings).\n\n");
 116     return;
 117 }
 118
 119 char *ui_module_options_init(char **defaults)
 120 {
 121     *defaults = NULL;
 122     return KILL_OPTION_STRING;
 123 }
 124
 125 int ui_module_options(int argc, char **argv)
 126 {
 127     int opt;
 128
 129     while ((opt = getopt(argc, argv, KILL_OPTION_STRING)) != -1) {
 130         char *tmp;
 131
 132         switch (opt) {
 133             case 's':
 134                 sig_index = 0;
 135
 136 again:
 137                 while ((tmp = strsep(&optarg, ",")) != NULL) {
 138                     int i;
 139                     int sig;
 140
 141                     if (isdigit(*tmp)) {
 142                         sig = atoi(tmp);
 143
 144                         for (i = 0; sigs[i].sig != -1; i++) {
 145                             if (sig == sigs[i].sig) {
 146                                 do_sigs = realloc(do_sigs, (sig_index + 2) * sizeof(int *));
 147                                 do_sigs[sig_index++] = sig;
 148                                 goto again;
 149                             }
 150                         }
 151                     }
 152
 153                     for (i = 0; sigs[i].name; i++) {
 154                         if (strcasecmp(tmp, sigs[i].name) == 0) {
 155                             do_sigs = realloc(do_sigs, (sig_index + 2) * sizeof(int *));
 156                             do_sigs[sig_index++] = sigs[i].sig;
 157                             goto again;
 158                         }
 159                     }
 160
 161                     warnx("kill.so: invalid signal -- %s", tmp);
 162                     return 1;
 163                 }
 164                 break;
 165             case '?':
 166                 warnx("kill.so: invalid option -- %c", optopt);
 167             default:
 168                 return 1;
 169         }
 170     }
 171
 172     return 0;
 173 }
 174
 175 static int killit(pid_t pid, int sig)
 176 {
 177     if (kill(pid, 0) == -1)
 178         return 1;
 179
 180     if (kill(pid, sig) == -1)
 181         return 1;
 182
 183     return 0;
 184 }
 185
 186 int ui_module_exec(char ***result, const struct passwd *pw, const int
 187         multi, const int verbose, const char *tf)
 188 {
 189     pid_t pid;
 190     char **strings = NULL;
 191     int i;
 192     char line[LINE_MAX] = {'\0'};
 193     char *tmp;
 194     char m[2] = {multi, '\0'};
 195
 196     strings = *result;
 197
 198     if (*result == NULL)
 199         add_string(&strings, "!");
 200     else {
 201         /* There may be more than one pid for multiple logins. Separated the
 202          * output with the multi-string deliminator and send the signals to each
 203          * pid. */
 204         while ((tmp = strsep(&*result[0], m)) != NULL) {
 205             char *s = "!";
 206
 207             if (isdigit(*tmp) == 0) {
 208                 strncat(line, "!", sizeof(line)-strlen(line)-1);
 209                 strncat(line, m, sizeof(line)-strlen(line)-1);
 210             }
 211             else {
 212                 pid = atol(tmp);
 213
 214                 for (i = 0; i < sig_index; i++) {
 215                     if (killit(pid, do_sigs[i]) == 0) {
 216                         s = "1";
 217                         break;
 218                     }
 219
 220                     s = "0";
 221                 }
 222
 223                 strncat(line, s, sizeof(line)-strlen(line)-1);
 224                 strncat(line, m, sizeof(line)-strlen(line)-1);
 225             }
 226         }
 227     }
 228
 229     line[strlen(line) - 1] = '\0';
 230     add_string(&strings, line);
 231     *result = strings;
 232     return 0;
 233 }