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 1.13 2004-11-17 08:23:34 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 char *plugin_control_help[] = {
  79         "  garden USER|SID       Put user into the walled garden",
  80         "  ungarden USER|SID     Release user",
  81         0
  82 };
  83
  84 int plugin_control(struct param_control *data)
  85 {
  86         sessionidt session;
  87         sessiont *s = 0;
  88         int flag;
  89         char *end;
  90
  91         if (data->argc < 1 || (strcmp(data->argv[0], "garden") && strcmp(data->argv[0], "ungarden")))
  92                 return PLUGIN_RET_OK; // not for us
  93
  94         flag = data->argv[0][0] == 'g';
  95
  96         if (!iam_master)        // All garden processing happens on the master.
  97         {
  98                 data->response = NSCTL_RES_ERR;
  99                 data->additional = "must be run on the cluster master";
 100                 return PLUGIN_RET_STOP;
 101         }
 102
 103         if (data->argc != 2)
 104         {
 105                 data->response = NSCTL_RES_ERR;
 106                 data->additional = "one argument required: username or session id";
 107                 return PLUGIN_RET_STOP;
 108         }
 109
 110         if (!(session = strtol(data->argv[0], &end, 10)) || *end)
 111                 session = p->get_session_by_username(data->argv[0]);
 112
 113         if (session)
 114                 s = p->get_session_by_id(session);
 115
 116         if (!s || !s->ip)
 117         {
 118                 data->response = NSCTL_RES_ERR;
 119                 data->additional = "session not found";
 120                 return PLUGIN_RET_STOP;
 121         }
 122
 123         if (s->walled_garden == flag)
 124         {
 125                 data->response = NSCTL_RES_ERR;
 126                 data->additional = flag ? "already in walled garden" : "not in walled garden";
 127                 return PLUGIN_RET_STOP;
 128         }
 129
 130         garden_session(s, flag);
 131         data->response = NSCTL_RES_OK;
 132         data->additional = 0;
 133
 134         return PLUGIN_RET_STOP;
 135 }
 136
 137 int plugin_become_master(void)
 138 {
 139         int i;
 140         iam_master = 1; // We just became the master. Wow!
 141
 142         for (i = 0; up_commands[i] && *up_commands[i]; i++)
 143         {
 144                 p->log(3, 0, 0, 0, "Running %s\n", up_commands[i]);
 145                 system(up_commands[i]);
 146         }
 147
 148         return PLUGIN_RET_OK;
 149 }
 150
 151 // Called for each active session after becoming master
 152 int plugin_new_session_master(sessiont * s)
 153 {
 154         if (s->walled_garden)
 155         {
 156                 s->walled_garden = 0;
 157                 garden_session(s, 1);
 158         }
 159
 160         return PLUGIN_RET_OK;
 161 }
 162
 163 int garden_session(sessiont *s, int flag)
 164 {
 165         char cmd[2048];
 166
 167         if (!s) return 0;
 168         if (!s->opened) return 0;
 169
 170         if (flag == 1)
 171         {
 172                 p->log(2, 0, 0, s->tunnel, "Garden user %s (%s)\n", s->user, p->inet_toa(htonl(s->ip)));
 173                 snprintf(cmd, sizeof(cmd), "iptables -t nat -A garden_users -s %s -j garden", p->inet_toa(htonl(s->ip)));
 174                 p->log(3, 0, 0, s->tunnel, "%s\n", cmd);
 175                 system(cmd);
 176                 s->walled_garden = 1;
 177         }
 178         else
 179         {
 180                 sessionidt other;
 181                 int count = 40;
 182
 183                 // Normal User
 184                 p->log(2, 0, 0, s->tunnel, "Un-Garden user %s (%s)\n", s->user, p->inet_toa(htonl(s->ip)));
 185                 // Kick off any duplicate usernames
 186                 // but make sure not to kick off ourself
 187                 if (s->ip && !s->die && (other = p->get_session_by_username(s->user)) && s != p->get_session_by_id(other)) {
 188                         p->sessionkill(other, "Duplicate session when user released from walled garden");
 189                 }
 190                 /* Clean up counters */
 191                 s->cin = s->cout = 0;
 192                 s->pin = s->pout = 0;
 193
 194                 snprintf(cmd, sizeof(cmd), "iptables -t nat -D garden_users -s %s -j garden", p->inet_toa(htonl(s->ip)));
 195                 p->log(3, 0, 0, s->tunnel, "%s\n", cmd);
 196                 while (--count)
 197                 {
 198                         int status = system(cmd);
 199                         if (WEXITSTATUS(status) != 0) break;
 200                 }
 201
 202                 s->walled_garden = 0;
 203
 204                 if (!s->die) {
 205                         /* OK, we're up! */
 206                         u16 r = p->radiusnew(p->get_id_by_session(s));
 207                         p->radiussend(r, RADIUSSTART);
 208                 }
 209         }
 210         s->walled_garden = flag;
 211         return 1;
 212 }
 213
 214 int plugin_init(struct pluginfuncs *funcs)
 215 {
 216         FILE *tables;
 217         int found_nat = 0;
 218
 219         if (!funcs)
 220                 return 0;
 221
 222         p = funcs;
 223
 224         if ((tables = fopen("/proc/net/ip_tables_names", "r")))
 225         {
 226                 char buf[1024];
 227                 while (fgets(buf, sizeof(buf), tables) && !found_nat)
 228                         found_nat = !strcmp(buf, "nat\n");
 229
 230                 fclose(tables);
 231         }
 232
 233         /* master killed/crashed? */
 234         if (found_nat)
 235         {
 236                 int i;
 237                 for (i = 0; down_commands[i] && *down_commands[i]; i++)
 238                 {
 239                         p->log(3, 0, 0, 0, "Running %s\n", down_commands[i]);
 240                         system(down_commands[i]);
 241                 }
 242         }
 243
 244         return 1;
 245 }
 246
 247 void plugin_done()
 248 {
 249         int i;
 250
 251         if (!iam_master)        // Never became master. nothing to do.
 252                 return;
 253
 254         for (i = 0; down_commands[i] && *down_commands[i]; i++)
 255         {
 256                 p->log(3, 0, 0, 0, "Running %s\n", down_commands[i]);
 257                 system(down_commands[i]);
 258         }
 259 }
 260