From: Lev Stipakov <lev.stipa...@f-secure.com> v4: - replace magic number with define - show user a decimal value instead of hex
v3: * move assert outside of loop * add max-clients value check to options v2: * Add round brackets for clarity * Rephrase comment Support for disabled peer-id When peer-id value is 0xFFFFFF, server should ignore it and treat packet in a same way as P_DATA_V1. --- src/openvpn/mudp.c | 13 ++++++++++--- src/openvpn/multi.c | 3 ++- src/openvpn/openvpn.h | 2 ++ src/openvpn/options.c | 5 +++++ 4 files changed, 19 insertions(+), 4 deletions(-) diff --git a/src/openvpn/mudp.c b/src/openvpn/mudp.c index 21a7e97..fec5e8d 100644 --- a/src/openvpn/mudp.c +++ b/src/openvpn/mudp.c @@ -64,12 +64,16 @@ multi_get_create_instance_udp (struct multi_context *m, bool *floated) struct hash_bucket *bucket = hash_bucket (hash, hv); uint8_t* ptr = BPTR(&m->top.c2.buf); uint8_t op = ptr[0] >> P_OPCODE_SHIFT; + bool v2 = (op == P_DATA_V2) && (m->top.c2.buf.len >= (1 + 3)); + bool peer_id_disabled = false; /* make sure buffer has enough length to read opcode (1 byte) and peer-id (3 bytes) */ - if (op == P_DATA_V2 && m->top.c2.buf.len >= (1 + 3)) + if (v2) { uint32_t peer_id = ntohl(*(uint32_t*)ptr) & 0xFFFFFF; - if ((peer_id < m->max_clients) && (m->instances[peer_id])) + peer_id_disabled = (peer_id == MAX_PEER_ID); + + if (!peer_id_disabled && (peer_id < m->max_clients) && (m->instances[peer_id])) { mi = m->instances[peer_id]; @@ -84,7 +88,7 @@ multi_get_create_instance_udp (struct multi_context *m, bool *floated) } } } - else + if (!v2 || peer_id_disabled) { he = hash_lookup_fast (hash, bucket, &real, hv); if (he) @@ -107,6 +111,9 @@ multi_get_create_instance_udp (struct multi_context *m, bool *floated) hash_add_fast (hash, bucket, &mi->real, hv, mi); mi->did_real_hash = true; + /* max_clients must be less then max peer-id value */ + ASSERT(m->max_clients < MAX_PEER_ID); + for (i = 0; i < m->max_clients; ++i) { if (!m->instances[i]) diff --git a/src/openvpn/multi.c b/src/openvpn/multi.c index ba7f2c0..3bc6ee9 100644 --- a/src/openvpn/multi.c +++ b/src/openvpn/multi.c @@ -605,7 +605,8 @@ multi_close_instance (struct multi_context *m, } #endif - m->instances[mi->context.c2.tls_multi->peer_id] = NULL; + if (mi->context.c2.tls_multi->peer_id != MAX_PEER_ID) + m->instances[mi->context.c2.tls_multi->peer_id] = NULL; schedule_remove_entry (m->schedule, (struct schedule_entry *) mi); diff --git a/src/openvpn/openvpn.h b/src/openvpn/openvpn.h index 1a458f1..ec8075d 100644 --- a/src/openvpn/openvpn.h +++ b/src/openvpn/openvpn.h @@ -595,4 +595,6 @@ struct context #define CIPHER_ENABLED(c) (false) #endif +#define MAX_PEER_ID 0xFFFFFF + #endif diff --git a/src/openvpn/options.c b/src/openvpn/options.c index c9688c3..29c76a6 100644 --- a/src/openvpn/options.c +++ b/src/openvpn/options.c @@ -5893,6 +5893,11 @@ add_option (struct options *options, msg (msglevel, "--max-clients must be at least 1"); goto err; } + if (max_clients >= MAX_PEER_ID) /* max peer-id value */ + { + msg (msglevel, "--max-clients must be less than 16777215"); + goto err; + } options->max_clients = max_clients; } else if (streq (p[0], "max-routes-per-client") && p[1] && !p[2]) -- 1.9.1 ------------------------------------------------------------------------------ _______________________________________________ Openvpn-devel mailing list Openvpn-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openvpn-devel