garden.c

   1 #include <string.h>
   2 #include <malloc.h>
   3 #include <stdlib.h>
   4 #include <sys/wait.h>
   5 #include <sys/types.h>
   6 #include "l2tpns.h"
   7 #include "plugin.h"
   8 #include "control.h"
   9
  10 char const *cvs_id = "$Id: garden.c,v 1.9 2004-11-03 13:23:58 bodea Exp $";
  11
  12 int __plugin_api_version = 1;
  13 static struct pluginfuncs *p = 0;
  14
  15 static int iam_master = 0;      // We're all slaves! Slaves I tell you!
  16
  17 char *up_commands[] = {
  18         "iptables -t nat -N garden >/dev/null 2>&1",                    // Create a chain that all gardened users will go through
  19         "iptables -t nat -F garden",
  20         ". " PLUGINCONF "/build-garden",                                // Populate with site-specific DNAT rules
  21         "iptables -t nat -N garden_users >/dev/null 2>&1",              // Empty chain, users added/removed by garden_session
  22         "iptables -t nat -F garden_users",
  23         "iptables -t nat -A PREROUTING -j garden_users",                // DNAT any users on the garden_users chain
  24         "sysctl -w net.ipv4.ip_conntrack_max=256000 >/dev/null",        // lots of entries
  25         NULL,
  26 };
  27
  28 char *down_commands[] = {
  29         "iptables -t nat -F PREROUTING",
  30         "iptables -t nat -F garden_users",
  31         "iptables -t nat -X garden_users",
  32         "iptables -t nat -F garden",
  33         "iptables -t nat -X garden",
  34         "rmmod iptable_nat",    // Should also remove ip_conntrack, but
  35                                 // doing so can take hours...  literally.
  36                                 // If a master is re-started as a slave,
  37                                 // either rmmod manually, or reboot.
  38         NULL,
  39 };
  40
  41 int garden_session(sessiont *s, int flag);
  42
  43 int plugin_post_auth(struct param_post_auth *data)
  44 {
  45         // Ignore if user authentication was successful
  46         if (data->auth_allowed) return PLUGIN_RET_OK;
  47
  48         p->_log(3, 0, 0, 0, "Walled Garden allowing login\n");
  49         data->auth_allowed = 1;
  50         data->s->walled_garden = 1;
  51         return PLUGIN_RET_OK;
  52 }
  53
  54 int plugin_new_session(struct param_new_session *data)
  55 {
  56         if (!iam_master)
  57                 return PLUGIN_RET_OK;   // Slaves don't do walled garden processing.
  58
  59         if (data->s->walled_garden)
  60                 garden_session(data->s, 1);
  61
  62         return PLUGIN_RET_OK;
  63 }
  64
  65 int plugin_kill_session(struct param_new_session *data)
  66 {
  67         if (!iam_master)
  68                 return PLUGIN_RET_OK;   // Slaves don't do walled garden processing.
  69
  70         if (data->s->walled_garden)
  71                 garden_session(data->s, 0);
  72
  73         return PLUGIN_RET_OK;
  74 }
  75
  76 int plugin_control(struct param_control *data)
  77 {
  78         sessiont *s;
  79         sessionidt session;
  80
  81         if (!iam_master)        // All garden processing happens on the master.
  82                 return PLUGIN_RET_OK;
  83
  84         if (data->type != PKT_GARDEN && data->type != PKT_UNGARDEN)
  85                 return PLUGIN_RET_OK;
  86
  87         if (!data->data && data->data_length)
  88                 return PLUGIN_RET_OK;
  89
  90         session = atoi((char*)(data->data));
  91         if (!session)
  92                 return PLUGIN_RET_OK;
  93
  94         data->send_response = 1;
  95         s = p->get_session_by_id(session);
  96         if (!s || !s->ip)
  97         {
  98                 char *errormsg = "Session not connected";
  99                 *(short *)(data->response + 2) = ntohs(PKT_RESP_ERROR);
 100                 sprintf((data->response + data->response_length), "%s", errormsg);
 101                 data->response_length += strlen(errormsg) + 1;
 102
 103                 p->_log(3, 0, 0, 0, "Unknown session %d\n", session);
 104                 return PLUGIN_RET_STOP;
 105         }
 106         *(short *)(data->response + 2) = ntohs(PKT_RESP_OK);
 107
 108         if (!(garden_session(s, (data->type == PKT_GARDEN))))
 109         {
 110                 char *errormsg = "User not connected";
 111                 *(short *)(data->response + 2) = ntohs(PKT_RESP_ERROR);
 112                 sprintf((data->response + data->response_length), "%s", errormsg);
 113                 data->response_length += strlen(errormsg) + 1;
 114         }
 115
 116         return PLUGIN_RET_STOP;
 117 }
 118
 119 int plugin_become_master(void)
 120 {
 121         int i;
 122         iam_master = 1; // We just became the master. Wow!
 123
 124         for (i = 0; up_commands[i] && *up_commands[i]; i++)
 125         {
 126                 p->_log(3, 0, 0, 0, "Running %s\n", up_commands[i]);
 127                 system(up_commands[i]);
 128         }
 129
 130         return PLUGIN_RET_OK;
 131 }
 132
 133 // Called for each active session after becoming master
 134 int plugin_new_session_master(sessiont * s)
 135 {
 136         if (s->walled_garden)
 137                 garden_session(s, 1);
 138
 139         return PLUGIN_RET_OK;
 140 }
 141
 142 int garden_session(sessiont *s, int flag)
 143 {
 144         char cmd[2048];
 145
 146         if (!s) return 0;
 147         if (!s->opened) return 0;
 148
 149         if (flag == 1)
 150         {
 151                 p->_log(2, 0, 0, s->tunnel, "Garden user %s (%s)\n", s->user, p->inet_toa(htonl(s->ip)));
 152                 snprintf(cmd, sizeof(cmd), "iptables -t nat -A garden_users -s %s -j garden", p->inet_toa(htonl(s->ip)));
 153                 p->_log(3, 0, 0, s->tunnel, "%s\n", cmd);
 154                 system(cmd);
 155                 s->walled_garden = 1;
 156         }
 157         else
 158         {
 159                 sessionidt other;
 160                 int count = 40;
 161
 162                 // Normal User
 163                 p->_log(2, 0, 0, s->tunnel, "Un-Garden user %s (%s)\n", s->user, p->inet_toa(htonl(s->ip)));
 164                 // Kick off any duplicate usernames
 165                 // but make sure not to kick off ourself
 166                 if (s->ip && !s->die && (other = p->get_session_by_username(s->user)) && s != p->get_session_by_id(other)) {
 167                         p->sessionkill(other, "Duplicate session when user released from walled garden");
 168                 }
 169                 /* Clean up counters */
 170                 s->cin = s->cout = 0;
 171                 s->pin = s->pout = 0;
 172
 173                 snprintf(cmd, sizeof(cmd), "iptables -t nat -D garden_users -s %s -j garden", p->inet_toa(htonl(s->ip)));
 174                 p->_log(3, 0, 0, s->tunnel, "%s\n", cmd);
 175                 while (--count)
 176                 {
 177                         int status = system(cmd);
 178                         if (WEXITSTATUS(status) != 0) break;
 179                 }
 180
 181                 s->walled_garden = 0;
 182
 183                 if (!s->die) {
 184                         /* OK, we're up! */
 185                         u16 r = p->radiusnew(p->get_id_by_session(s));
 186                         p->radiussend(r, RADIUSSTART);
 187                 }
 188         }
 189         s->walled_garden = flag;
 190         return 1;
 191 }
 192
 193 int plugin_init(struct pluginfuncs *funcs)
 194 {
 195         FILE *tables;
 196         int found_nat = 0;
 197
 198         if (!funcs)
 199                 return 0;
 200
 201         p = funcs;
 202
 203         if ((tables = fopen("/proc/net/ip_tables_names", "r")))
 204         {
 205                 char buf[1024];
 206                 while (fgets(buf, sizeof(buf), tables) && !found_nat)
 207                         found_nat = !strcmp(buf, "nat\n");
 208
 209                 fclose(tables);
 210         }
 211
 212         /* master killed/crashed? */
 213         if (found_nat)
 214         {
 215                 int i;
 216                 for (i = 0; down_commands[i] && *down_commands[i]; i++)
 217                 {
 218                         p->_log(3, 0, 0, 0, "Running %s\n", down_commands[i]);
 219                         system(down_commands[i]);
 220                 }
 221         }
 222
 223         return 1;
 224 }
 225
 226 void plugin_done()
 227 {
 228         int i;
 229
 230         if (!iam_master)        // Never became master. nothing to do.
 231                 return;
 232
 233         for (i = 0; down_commands[i] && *down_commands[i]; i++)
 234         {
 235                 p->_log(3, 0, 0, 0, "Running %s\n", down_commands[i]);
 236                 system(down_commands[i]);
 237         }
 238 }
 239