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 1.14 2004/11/17 15:08:19 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 from garden",
  81         0
  82 };
  83
  84 int plugin_control(struct param_control *data)
  85 {
  86         sessionidt s;
  87         sessiont *sess = 0;
  88         int flag;
  89         char *end;
  90
  91         if (data->argc < 1)
  92                 return PLUGIN_RET_OK;
  93
  94         if (strcmp(data->argv[0], "garden") && strcmp(data->argv[0], "ungarden"))
  95                 return PLUGIN_RET_OK; // not for us
  96
  97         flag = data->argv[0][0] != 'u';
  98
  99         if (!iam_master)        // All garden processing happens on the master.
 100         {
 101                 data->response = NSCTL_RES_ERR;
 102                 data->additional = "must be run on the cluster master";
 103                 return PLUGIN_RET_STOP;
 104         }
 105
 106         if (data->argc != 2)
 107         {
 108                 data->response = NSCTL_RES_ERR;
 109                 data->additional = "one argument required: username or session id";
 110                 return PLUGIN_RET_STOP;
 111         }
 112
 113         if (!(session = strtol(data->argv[1], &end, 10)) || *end)
 114                 session = p->get_session_by_username(data->argv[1]);
 115
 116         if (session)
 117                 s = p->get_session_by_id(session);
 118
 119         if (!s || !s->ip)
 120         {
 121                 data->response = NSCTL_RES_ERR;
 122                 data->additional = "session not found";
 123                 return PLUGIN_RET_STOP;
 124         }
 125
 126         if (s->walled_garden == flag)
 127         {
 128                 data->response = NSCTL_RES_ERR;
 129                 data->additional = flag ? "already in walled garden" : "not in walled garden";
 130                 return PLUGIN_RET_STOP;
 131         }
 132
 133         garden_session(s, flag);
 134         p->sesssion_changed(session);
 135
 136         data->response = NSCTL_RES_OK;
 137         data->additional = 0;
 138
 139         return PLUGIN_RET_STOP;
 140 }
 141
 142 int plugin_become_master(void)
 143 {
 144         int i;
 145         iam_master = 1; // We just became the master. Wow!
 146
 147         for (i = 0; up_commands[i] && *up_commands[i]; i++)
 148         {
 149                 p->log(3, 0, 0, 0, "Running %s\n", up_commands[i]);
 150                 system(up_commands[i]);
 151         }
 152
 153         return PLUGIN_RET_OK;
 154 }
 155
 156 // Called for each active session after becoming master
 157 int plugin_new_session_master(sessiont *s)
 158 {
 159         if (s->walled_garden)
 160         {
 161                 s->walled_garden = 0;
 162                 garden_session(s, 1);
 163         }
 164
 165         return PLUGIN_RET_OK;
 166 }
 167
 168 int garden_session(sessiont *s, int flag)
 169 {
 170         char cmd[2048];
 171
 172         if (!s) return 0;
 173         if (!s->opened) return 0;
 174
 175         if (flag == 1)
 176         {
 177                 p->log(2, 0, 0, s->tunnel, "Garden user %s (%s)\n", s->user, p->inet_toa(htonl(s->ip)));
 178                 snprintf(cmd, sizeof(cmd), "iptables -t nat -A garden_users -s %s -j garden", p->inet_toa(htonl(s->ip)));
 179                 p->log(3, 0, 0, s->tunnel, "%s\n", cmd);
 180                 system(cmd);
 181                 s->walled_garden = 1;
 182         }
 183         else
 184         {
 185                 sessionidt other;
 186                 int count = 40;
 187
 188                 // Normal User
 189                 p->log(2, 0, 0, s->tunnel, "Un-Garden user %s (%s)\n", s->user, p->inet_toa(htonl(s->ip)));
 190                 // Kick off any duplicate usernames
 191                 // but make sure not to kick off ourself
 192                 if (s->ip && !s->die && (other = p->get_session_by_username(s->user)) && s != p->get_session_by_id(other)) {
 193                         p->sessionkill(other, "Duplicate session when user released from walled garden");
 194                 }
 195                 /* Clean up counters */
 196                 s->cin = s->cout = 0;
 197                 s->pin = s->pout = 0;
 198
 199                 snprintf(cmd, sizeof(cmd), "iptables -t nat -D garden_users -s %s -j garden", p->inet_toa(htonl(s->ip)));
 200                 p->log(3, 0, 0, s->tunnel, "%s\n", cmd);
 201                 while (--count)
 202                 {
 203                         int status = system(cmd);
 204                         if (WEXITSTATUS(status) != 0) break;
 205                 }
 206
 207                 s->walled_garden = 0;
 208
 209                 if (!s->die) {
 210                         /* OK, we're up! */
 211                         u16 r = p->radiusnew(p->get_id_by_session(s));
 212                         p->radiussend(r, RADIUSSTART);
 213                 }
 214         }
 215         s->walled_garden = flag;
 216         return 1;
 217 }
 218
 219 int plugin_init(struct pluginfuncs *funcs)
 220 {
 221         FILE *tables;
 222         int found_nat = 0;
 223
 224         if (!funcs)
 225                 return 0;
 226
 227         p = funcs;
 228
 229         if ((tables = fopen("/proc/net/ip_tables_names", "r")))
 230         {
 231                 char buf[1024];
 232                 while (fgets(buf, sizeof(buf), tables) && !found_nat)
 233                         found_nat = !strcmp(buf, "nat\n");
 234
 235                 fclose(tables);
 236         }
 237
 238         /* master killed/crashed? */
 239         if (found_nat)
 240         {
 241                 int i;
 242                 for (i = 0; down_commands[i] && *down_commands[i]; i++)
 243                 {
 244                         p->log(3, 0, 0, 0, "Running %s\n", down_commands[i]);
 245                         system(down_commands[i]);
 246                 }
 247         }
 248
 249         return 1;
 250 }
 251
 252 void plugin_done()
 253 {
 254         int i;
 255
 256         if (!iam_master)        // Never became master. nothing to do.
 257                 return;
 258
 259         for (i = 0; down_commands[i] && *down_commands[i]; i++)
 260         {
 261                 p->log(3, 0, 0, 0, "Running %s\n", down_commands[i]);
 262                 system(down_commands[i]);
 263         }
 264 }
 265