// Copyright (c) 2002 FireBrick (Andrews & Arnold Ltd / Watchfront Ltd) - GPL licenced
// vim: sw=8 ts=8
-char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.57 2004/11/27 05:19:53 bodea Exp $";
+char const *cvs_id_l2tpns = "$Id: l2tpns.c,v 1.59 2004/11/28 20:10:04 bodea Exp $";
#include <arpa/inet.h>
#include <assert.h>
t = session[s].tunnel;
sp = &session[s];
+ // run access-list if any
+ if (session[s].filter_out && !ip_filter(buf, len, session[s].filter_out - 1))
+ return;
+
if (sp->tbf_out)
{
// Are we throttling this session?
}
}
+// add/remove filters from session (-1 = no change)
+void filter_session(sessionidt s, int filter_in, int filter_out)
+{
+ if (!session[s].tunnel)
+ return; // No-one home.
+
+ if (!*session[s].user)
+ return; // User not logged in
+
+ // paranoia
+ if (filter_in > MAXFILTER) filter_in = -1;
+ if (filter_out > MAXFILTER) filter_out = -1;
+ if (session[s].filter_in > MAXFILTER) session[s].filter_in = 0;
+ if (session[s].filter_out > MAXFILTER) session[s].filter_out = 0;
+
+ if (filter_in >= 0)
+ {
+ if (session[s].filter_in)
+ ip_filters[session[s].filter_in - 1].used--;
+
+ if (filter_in > 0)
+ ip_filters[filter_in - 1].used++;
+
+ session[s].filter_in = filter_in;
+ }
+
+ if (filter_out >= 0)
+ {
+ if (session[s].filter_out)
+ ip_filters[session[s].filter_out - 1].used--;
+
+ if (filter_out > 0)
+ ip_filters[filter_out - 1].used++;
+
+ session[s].filter_out = filter_out;
+ }
+}
+
// start tidy shutdown of session
void sessionshutdown(sessionidt s, char *reason)
{
if (!session[s].die)
session[s].die = now() + 150; // Clean up in 15 seconds
+ // update filter refcounts
+ if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--;
+ if (session[s].filter_out) ip_filters[session[s].filter_out - 1].used--;
+
cluster_send_session(s);
}
send++;
}
+ if (a & CLI_SESS_NOFILTER)
+ {
+ LOG(2, 0, s, session[s].tunnel, "Un-filtering session by CLI\n");
+ filter_session(s, 0, 0);
+ send++;
+ }
+ else if (a & CLI_SESS_FILTER)
+ {
+ LOG(2, 0, s, session[s].tunnel, "Filtering session by CLI (in=%d, out=%d)\n",
+ cli_session_actions[s].filter_in,
+ cli_session_actions[s].filter_out);
+
+ filter_session(s, cli_session_actions[s].filter_in, cli_session_actions[s].filter_out);
+ send++;
+ }
+
if (send)
cluster_send_session(s);
}
}
+ // check filters
+ if (new->filter_in && (new->filter_in > MAXFILTER || !ip_filters[new->filter_in - 1].name[0]))
+ {
+ LOG(2, session[s].ip, s, session[s].tunnel, "Dropping invalid input filter %d\n", (int) new->filter_in);
+ new->filter_in = 0;
+ }
+
+ if (new->filter_out && (new->filter_out > MAXFILTER || !ip_filters[new->filter_out - 1].name[0]))
+ {
+ LOG(2, session[s].ip, s, session[s].tunnel, "Dropping invalid output filter %d\n", (int) new->filter_out);
+ new->filter_out = 0;
+ }
+
+ if (new->filter_in != session[s].filter_in)
+ {
+ if (session[s].filter_in) ip_filters[session[s].filter_in - 1].used--;
+ if (new->filter_in) ip_filters[new->filter_in - 1].used++;
+ }
+
+ if (new->filter_out != session[s].filter_out)
+ {
+ if (session[s].filter_out) ip_filters[session[s].filter_out - 1].used--;
+ if (new->filter_out) ip_filters[new->filter_out - 1].used++;
+ }
+
if (new->tunnel && s > config->cluster_highest_sessionid) // Maintain this in the slave. It's used
// for walking the sessions to forward byte counts to the master.
config->cluster_highest_sessionid = s;
return hidden_length + 6;
}
+static int ip_filter_port(ip_filter_portt *p, portt port)
+{
+ switch (p->op)
+ {
+ case FILTER_PORT_OP_EQ: return port == p->port;
+ case FILTER_PORT_OP_NEQ: return port != p->port;
+ case FILTER_PORT_OP_GT: return port > p->port;
+ case FILTER_PORT_OP_LT: return port < p->port;
+ case FILTER_PORT_OP_RANGE: return port >= p->port && port <= p->port2;
+ }
+
+ return 0;
+}
+
+static int ip_filter_flag(u8 op, u8 sflags, u8 cflags, u8 flags)
+{
+ switch (op)
+ {
+ /*
+ * NOTE: "match-any +A +B -C -D" is interpreted as "match if
+ * either A or B is set *and* C or D is clear". While "or" is
+ * possibly more correct, the way "established" is currently
+ * implemented depends on this behaviour.
+ */
+ case FILTER_FLAG_OP_ANY:
+ return (flags & sflags) && !(flags & cflags);
+
+ case FILTER_FLAG_OP_ALL:
+ return (flags & sflags) == sflags && (~flags & cflags) == cflags;
+ }
+
+ return 0;
+}
+
+int ip_filter(u8 *buf, int len, u8 filter)
+{
+ u8 proto;
+ ipt src_ip;
+ ipt dst_ip;
+ portt src_port = 0;
+ portt dst_port = 0;
+ u8 flags = 0;
+ ip_filter_rulet *rule;
+
+ if (len < 20) // up to end of destination address
+ return 0;
+
+ if (*buf >> 4) // IPv4
+ return 0;
+
+ proto = buf[9];
+ src_ip = *(u32 *) (buf + 12);
+ dst_ip = *(u32 *) (buf + 16);
+
+ if (proto == IPPROTO_TCP || proto == IPPROTO_UDP)
+ {
+ int l = buf[0] & 0xf;
+ if (len < l + 4) // ports
+ return 0;
+
+ src_port = ntohs(*(u16 *) (buf + l));
+ dst_port = ntohs(*(u16 *) (buf + l + 2));
+ if (proto == IPPROTO_TCP)
+ {
+ if (len < l + 15) // flags
+ return 0;
+
+ flags = buf[l + 14] & 0x3f;
+ }
+ }
+
+ for (rule = ip_filters[filter].rules; rule->action; rule++)
+ {
+ if (proto && proto != rule->proto)
+ continue;
+
+ if (rule->src_wild != INADDR_BROADCAST &&
+ (src_ip & ~rule->src_wild) != (rule->src_ip & ~rule->src_wild))
+ continue;
+
+ if (rule->dst_wild != INADDR_BROADCAST &&
+ (dst_ip & ~rule->dst_wild) != (rule->dst_ip & ~rule->dst_wild))
+ continue;
+
+ if (proto == IPPROTO_TCP || proto == IPPROTO_UDP)
+ {
+ if (rule->src_ports.op && !ip_filter_port(&rule->src_ports, src_port))
+ continue;
+
+ if (rule->dst_ports.op && !ip_filter_port(&rule->dst_ports, dst_port))
+ continue;
+
+ if (proto == IPPROTO_TCP && rule->tcp_flag_op &&
+ !ip_filter_flag(rule->tcp_flag_op, rule->tcp_sflags, rule->tcp_cflags, flags))
+ continue;
+ }
+
+ // matched
+ return rule->action == FILTER_ACTION_PERMIT;
+ }
+
+ // default deny
+ return 0;
+}
projects / l2tpns.git / blobdiff