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 /* walled garden */
  11
  12 char const *cvs_id = "$Id: garden.c,v 1.12 2004/11/09 08:05:02 bodea Exp $";
  13
  14 int __plugin_api_version = PLUGIN_API_VERSION;
  15 static struct pluginfuncs *p = 0;
  16
  17 static int iam_master = 0;      // We're all slaves! Slaves I tell you!
  18
  19 char *up_commands[] = {
  20         "iptables -t nat -N garden >/dev/null 2>&1",                    // Create a chain that all gardened users will go through
  21         "iptables -t nat -F garden",
  22         ". " PLUGINCONF "/build-garden",                                // Populate with site-specific DNAT rules
  23         "iptables -t nat -N garden_users >/dev/null 2>&1",              // Empty chain, users added/removed by garden_session
  24         "iptables -t nat -F garden_users",
  25         "iptables -t nat -A PREROUTING -j garden_users",                // DNAT any users on the garden_users chain
  26         "sysctl -w net.ipv4.ip_conntrack_max=256000 >/dev/null",        // lots of entries
  27         NULL,
  28 };
  29
  30 char *down_commands[] = {
  31         "iptables -t nat -F PREROUTING",
  32         "iptables -t nat -F garden_users",
  33         "iptables -t nat -X garden_users",
  34         "iptables -t nat -F garden",
  35         "iptables -t nat -X garden",
  36         "rmmod iptable_nat",    // Should also remove ip_conntrack, but
  37                                 // doing so can take hours...  literally.
  38                                 // If a master is re-started as a slave,
  39                                 // either rmmod manually, or reboot.
  40         NULL,
  41 };
  42
  43 int garden_session(sessiont *s, int flag);
  44
  45 int plugin_post_auth(struct param_post_auth *data)
  46 {
  47         // Ignore if user authentication was successful
  48         if (data->auth_allowed) return PLUGIN_RET_OK;
  49
  50         p->log(3, 0, 0, 0, "Walled Garden allowing login\n");
  51         data->auth_allowed = 1;
  52         data->s->walled_garden = 1;
  53         return PLUGIN_RET_OK;
  54 }
  55
  56 int plugin_new_session(struct param_new_session *data)
  57 {
  58         if (!iam_master)
  59                 return PLUGIN_RET_OK;   // Slaves don't do walled garden processing.
  60
  61         if (data->s->walled_garden)
  62                 garden_session(data->s, 1);
  63
  64         return PLUGIN_RET_OK;
  65 }
  66
  67 int plugin_kill_session(struct param_new_session *data)
  68 {
  69         if (!iam_master)
  70                 return PLUGIN_RET_OK;   // Slaves don't do walled garden processing.
  71
  72         if (data->s->walled_garden)
  73                 garden_session(data->s, 0);
  74
  75         return PLUGIN_RET_OK;
  76 }
  77
  78 int plugin_control(struct param_control *data)
  79 {
  80         sessiont *s;
  81         sessionidt session;
  82
  83         if (!iam_master)        // All garden processing happens on the master.
  84                 return PLUGIN_RET_OK;
  85
  86         if (data->type != PKT_GARDEN && data->type != PKT_UNGARDEN)
  87                 return PLUGIN_RET_OK;
  88
  89         if (!data->data && data->data_length)
  90                 return PLUGIN_RET_OK;
  91
  92         session = atoi((char*)(data->data));
  93         if (!session)
  94                 return PLUGIN_RET_OK;
  95
  96         data->send_response = 1;
  97         s = p->get_session_by_id(session);
  98         if (!s || !s->ip)
  99         {
 100                 char *errormsg = "Session not connected";
 101                 *(short *)(data->response + 2) = ntohs(PKT_RESP_ERROR);
 102                 sprintf((data->response + data->response_length), "%s", errormsg);
 103                 data->response_length += strlen(errormsg) + 1;
 104
 105                 p->log(3, 0, 0, 0, "Unknown session %d\n", session);
 106                 return PLUGIN_RET_STOP;
 107         }
 108         *(short *)(data->response + 2) = ntohs(PKT_RESP_OK);
 109
 110         if (!(garden_session(s, (data->type == PKT_GARDEN))))
 111         {
 112                 char *errormsg = "User not connected";
 113                 *(short *)(data->response + 2) = ntohs(PKT_RESP_ERROR);
 114                 sprintf((data->response + data->response_length), "%s", errormsg);
 115                 data->response_length += strlen(errormsg) + 1;
 116         }
 117
 118         return PLUGIN_RET_STOP;
 119 }
 120
 121 int plugin_become_master(void)
 122 {
 123         int i;
 124         iam_master = 1; // We just became the master. Wow!
 125
 126         for (i = 0; up_commands[i] && *up_commands[i]; i++)
 127         {
 128                 p->log(3, 0, 0, 0, "Running %s\n", up_commands[i]);
 129                 system(up_commands[i]);
 130         }
 131
 132         return PLUGIN_RET_OK;
 133 }
 134
 135 // Called for each active session after becoming master
 136 int plugin_new_session_master(sessiont * s)
 137 {
 138         if (s->walled_garden)
 139                 garden_session(s, 1);
 140
 141         return PLUGIN_RET_OK;
 142 }
 143
 144 int garden_session(sessiont *s, int flag)
 145 {
 146         char cmd[2048];
 147
 148         if (!s) return 0;
 149         if (!s->opened) return 0;
 150
 151         if (flag == 1)
 152         {
 153                 p->log(2, 0, 0, s->tunnel, "Garden user %s (%s)\n", s->user, p->inet_toa(htonl(s->ip)));
 154                 snprintf(cmd, sizeof(cmd), "iptables -t nat -A garden_users -s %s -j garden", p->inet_toa(htonl(s->ip)));
 155                 p->log(3, 0, 0, s->tunnel, "%s\n", cmd);
 156                 system(cmd);
 157                 s->walled_garden = 1;
 158         }
 159         else
 160         {
 161                 sessionidt other;
 162                 int count = 40;
 163
 164                 // Normal User
 165                 p->log(2, 0, 0, s->tunnel, "Un-Garden user %s (%s)\n", s->user, p->inet_toa(htonl(s->ip)));
 166                 // Kick off any duplicate usernames
 167                 // but make sure not to kick off ourself
 168                 if (s->ip && !s->die && (other = p->get_session_by_username(s->user)) && s != p->get_session_by_id(other)) {
 169                         p->sessionkill(other, "Duplicate session when user released from walled garden");
 170                 }
 171                 /* Clean up counters */
 172                 s->cin = s->cout = 0;
 173                 s->pin = s->pout = 0;
 174
 175                 snprintf(cmd, sizeof(cmd), "iptables -t nat -D garden_users -s %s -j garden", p->inet_toa(htonl(s->ip)));
 176                 p->log(3, 0, 0, s->tunnel, "%s\n", cmd);
 177                 while (--count)
 178                 {
 179                         int status = system(cmd);
 180                         if (WEXITSTATUS(status) != 0) break;
 181                 }
 182
 183                 s->walled_garden = 0;
 184
 185                 if (!s->die) {
 186                         /* OK, we're up! */
 187                         u16 r = p->radiusnew(p->get_id_by_session(s));
 188                         p->radiussend(r, RADIUSSTART);
 189                 }
 190         }
 191         s->walled_garden = flag;
 192         return 1;
 193 }
 194
 195 int plugin_init(struct pluginfuncs *funcs)
 196 {
 197         FILE *tables;
 198         int found_nat = 0;
 199
 200         if (!funcs)
 201                 return 0;
 202
 203         p = funcs;
 204
 205         if ((tables = fopen("/proc/net/ip_tables_names", "r")))
 206         {
 207                 char buf[1024];
 208                 while (fgets(buf, sizeof(buf), tables) && !found_nat)
 209                         found_nat = !strcmp(buf, "nat\n");
 210
 211                 fclose(tables);
 212         }
 213
 214         /* master killed/crashed? */
 215         if (found_nat)
 216         {
 217                 int i;
 218                 for (i = 0; down_commands[i] && *down_commands[i]; i++)
 219                 {
 220                         p->log(3, 0, 0, 0, "Running %s\n", down_commands[i]);
 221                         system(down_commands[i]);
 222                 }
 223         }
 224
 225         return 1;
 226 }
 227
 228 void plugin_done()
 229 {
 230         int i;
 231
 232         if (!iam_master)        // Never became master. nothing to do.
 233                 return;
 234
 235         for (i = 0; down_commands[i] && *down_commands[i]; i++)
 236         {
 237                 p->log(3, 0, 0, 0, "Running %s\n", down_commands[i]);
 238                 system(down_commands[i]);
 239         }
 240 }
 241