X-Git-Url: http://git.sameswireless.fr/l2tpns.git/blobdiff_plain/4f253feef08f01c03bc63f70f9de3937541ccd79..8f01a9dbf21dbd39368a62fe3102c975e1e7be89:/cluster.c diff --git a/cluster.c b/cluster.c index 41dc10f..abe2a63 100644 --- a/cluster.c +++ b/cluster.c @@ -1,6 +1,6 @@ // L2TPNS Clustering Stuff -char const *cvs_id_cluster = "$Id: cluster.c,v 1.44 2005/06/28 14:48:19 bodea Exp $"; +char const *cvs_id_cluster = "$Id: cluster.c,v 1.51 2006/04/27 09:53:49 bodea Exp $"; #include #include @@ -42,6 +42,7 @@ extern int cluster_sockfd; // The filedescriptor for the cluster communications in_addr_t my_address = 0; // The network address of my ethernet port. static int walk_session_number = 0; // The next session to send when doing the slow table walk. +static int walk_bundle_number = 0; // The next bundle to send when doing the slow table walk. static int walk_tunnel_number = 0; // The next tunnel to send when doing the slow table walk. int forked = 0; // Sanity check: CLI must not diddle with heartbeat table @@ -56,7 +57,7 @@ static struct { static struct { int seq; int size; - char data[MAX_HEART_SIZE]; + uint8_t data[MAX_HEART_SIZE]; } past_hearts[HB_HISTORY_SIZE]; // Ring buffer of heartbeats that we've recently sent out. Needed so // we can re-transmit if needed. @@ -85,6 +86,7 @@ int cluster_init() int opt; config->cluster_undefined_sessions = MAXSESSION-1; + config->cluster_undefined_bundles = MAXBUNDLE-1; config->cluster_undefined_tunnels = MAXTUNNEL-1; if (!config->cluster_address) @@ -127,6 +129,15 @@ int cluster_init() opt = 0; // Turn off multicast loopback. setsockopt(cluster_sockfd, IPPROTO_IP, IP_MULTICAST_LOOP, &opt, sizeof(opt)); + if (config->cluster_mcast_ttl != 1) + { + uint8_t ttl = 0; + if (config->cluster_mcast_ttl > 0) + ttl = config->cluster_mcast_ttl < 256 ? config->cluster_mcast_ttl : 255; + + setsockopt(cluster_sockfd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)); + } + if (setsockopt(cluster_sockfd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) { LOG(0, 0, 0, "Failed to setsockopt (join mcast group): %s\n", strerror(errno)); @@ -178,7 +189,7 @@ static int cluster_send_data(void *data, int datalen) // Maintains the format. Assumes that the caller // has passed in a big enough buffer! // -static void add_type(char **p, int type, int more, char *data, int size) +static void add_type(uint8_t **p, int type, int more, uint8_t *data, int size) { *((uint32_t *) (*p)) = type; *p += sizeof(uint32_t); @@ -218,7 +229,7 @@ static void cluster_uptodate(void) if (config->cluster_iam_uptodate) return; - if (config->cluster_undefined_sessions || config->cluster_undefined_tunnels) + if (config->cluster_undefined_sessions || config->cluster_undefined_tunnels || config->cluster_undefined_bundles) return; config->cluster_iam_uptodate = 1; @@ -231,7 +242,7 @@ static void cluster_uptodate(void) // Send a unicast UDP packet to a peer with 'data' as the // contents. // -static int peer_send_data(in_addr_t peer, char *data, int size) +static int peer_send_data(in_addr_t peer, uint8_t *data, int size) { struct sockaddr_in addr = {0}; @@ -259,10 +270,10 @@ static int peer_send_data(in_addr_t peer, char *data, int size) // // Send a structured message to a peer with a single element of type 'type'. // -static int peer_send_message(in_addr_t peer, int type, int more, char *data, int size) +static int peer_send_message(in_addr_t peer, int type, int more, uint8_t *data, int size) { - char buf[65536]; // Vast overkill. - char *p = buf; + uint8_t buf[65536]; // Vast overkill. + uint8_t *p = buf; LOG(4, 0, 0, "Sending message to peer (type %d, more %d, size %d)\n", type, more, size); add_type(&p, type, more, data, size); @@ -271,10 +282,10 @@ static int peer_send_message(in_addr_t peer, int type, int more, char *data, int } // send a packet to the master -static int _forward_packet(char *data, int size, in_addr_t addr, int port, int type) +static int _forward_packet(uint8_t *data, int size, in_addr_t addr, int port, int type) { - char buf[65536]; // Vast overkill. - char *p = buf; + uint8_t buf[65536]; // Vast overkill. + uint8_t *p = buf; if (!config->cluster_master_address) // No election has been held yet. Just skip it. return -1; @@ -282,7 +293,7 @@ static int _forward_packet(char *data, int size, in_addr_t addr, int port, int t LOG(4, 0, 0, "Forwarding packet from %s to master (size %d)\n", fmtaddr(addr, 0), size); STAT(c_forwarded); - add_type(&p, type, addr, (char *) &port, sizeof(port)); // ick. should be uint16_t + add_type(&p, type, addr, (uint8_t *) &port, sizeof(port)); // ick. should be uint16_t memcpy(p, data, size); p += size; @@ -295,13 +306,13 @@ static int _forward_packet(char *data, int size, in_addr_t addr, int port, int t // The master just processes the payload as if it had // received it off the tun device. // -int master_forward_packet(char *data, int size, in_addr_t addr, int port) +int master_forward_packet(uint8_t *data, int size, in_addr_t addr, int port) { return _forward_packet(data, size, addr, port, C_FORWARD); } // Forward a DAE RADIUS packet to the master. -int master_forward_dae_packet(char *data, int size, in_addr_t addr, int port) +int master_forward_dae_packet(uint8_t *data, int size, in_addr_t addr, int port) { return _forward_packet(data, size, addr, port, C_FORWARD_DAE); } @@ -313,10 +324,10 @@ int master_forward_dae_packet(char *data, int size, in_addr_t addr, int port) // token bucket queue, and lets normal processing take care // of it. // -int master_throttle_packet(int tbfid, char *data, int size) +int master_throttle_packet(int tbfid, uint8_t *data, int size) { - char buf[65536]; // Vast overkill. - char *p = buf; + uint8_t buf[65536]; // Vast overkill. + uint8_t *p = buf; if (!config->cluster_master_address) // No election has been held yet. Just skip it. return -1; @@ -338,10 +349,10 @@ int master_throttle_packet(int tbfid, char *data, int size) // // (Note that this must be called with the tun header // as the start of the data). -int master_garden_packet(sessionidt s, char *data, int size) +int master_garden_packet(sessionidt s, uint8_t *data, int size) { - char buf[65536]; // Vast overkill. - char *p = buf; + uint8_t buf[65536]; // Vast overkill. + uint8_t *p = buf; if (!config->cluster_master_address) // No election has been held yet. Just skip it. return -1; @@ -358,7 +369,7 @@ int master_garden_packet(sessionidt s, char *data, int size) // Send a chunk of data as a heartbeat.. // We save it in the history buffer as we do so. // -static void send_heartbeat(int seq, char *data, int size) +static void send_heartbeat(int seq, uint8_t *data, int size) { int i; @@ -380,8 +391,8 @@ static void send_heartbeat(int seq, char *data, int size) // void cluster_send_ping(time_t basetime) { - char buff[100 + sizeof(pingt)]; - char *p = buff; + uint8_t buff[100 + sizeof(pingt)]; + uint8_t *p = buff; pingt x; if (config->cluster_iam_master && basetime) // We're heartbeating so no need to ping. @@ -394,7 +405,7 @@ void cluster_send_ping(time_t basetime) x.undef = config->cluster_undefined_sessions + config->cluster_undefined_tunnels; x.basetime = basetime; - add_type(&p, C_PING, basetime, (char *) &x, sizeof(x)); + add_type(&p, C_PING, basetime, (uint8_t *) &x, sizeof(x)); cluster_send_data(buff, (p-buff) ); } @@ -456,7 +467,7 @@ void master_update_counts(void) // Forward the data to the master. LOG(4, 0, 0, "Sending byte counters to master (%d elements)\n", c); - peer_send_message(config->cluster_master_address, C_BYTES, c, (char *) &b, sizeof(b[0]) * c); + peer_send_message(config->cluster_master_address, C_BYTES, c, (uint8_t *) &b, sizeof(b[0]) * c); return; } @@ -511,7 +522,7 @@ void cluster_check_slaves(void) // void cluster_check_master(void) { - int i, count, tcount, high_unique_id = 0; + int i, count, tcount, bcount, high_unique_id = 0; int last_free = 0; clockt t = TIME; static int probed = 0; @@ -605,6 +616,19 @@ void cluster_check_master(void) config->cluster_highest_tunnelid = i; } + // + // Go through and mark all the bundles as defined. + // Count the highest used bundle number as well. + // + config->cluster_highest_bundleid = 0; + for (i = 0, bcount = 0; i < MAXBUNDLE; ++i) { + if (bundle[i].state == BUNDLEUNDEF) + bundle[i].state = BUNDLEFREE; + + if (bundle[i].state != BUNDLEFREE && i > config->cluster_highest_bundleid) + config->cluster_highest_bundleid = i; + } + // // Go through and mark all the sessions as being defined. // reset the idle timeouts. @@ -666,10 +690,11 @@ void cluster_check_master(void) rebuild_address_pool(); // If we're not the very first master, this is a big issue! - if(count>0) + if (count > 0) LOG(0, 0, 0, "Warning: Fixed %d uninitialized sessions in becoming master!\n", count); config->cluster_undefined_sessions = 0; + config->cluster_undefined_bundles = 0; config->cluster_undefined_tunnels = 0; config->cluster_iam_uptodate = 1; // assume all peers are up-to-date @@ -687,7 +712,7 @@ void cluster_check_master(void) // we fix it up here, and we ensure that the 'first free session' // pointer is valid. // -static void cluster_check_sessions(int highsession, int freesession_ptr, int hightunnel) +static void cluster_check_sessions(int highsession, int freesession_ptr, int highbundle, int hightunnel) { int i; @@ -696,7 +721,7 @@ static void cluster_check_sessions(int highsession, int freesession_ptr, int hig if (config->cluster_iam_uptodate) return; - if (highsession > config->cluster_undefined_sessions && hightunnel > config->cluster_undefined_tunnels) + if (highsession > config->cluster_undefined_sessions && highbundle > config->cluster_undefined_bundles && hightunnel > config->cluster_undefined_tunnels) return; // Clear out defined sessions, counting the number of @@ -712,6 +737,19 @@ static void cluster_check_sessions(int highsession, int freesession_ptr, int hig ++config->cluster_undefined_sessions; } + // Clear out defined bundles, counting the number of + // undefs remaining. + config->cluster_undefined_bundles = 0; + for (i = 1 ; i < MAXBUNDLE; ++i) { + if (i > highbundle) { + if (bundle[i].state == BUNDLEUNDEF) bundle[i].state = BUNDLEFREE; // Defined. + continue; + } + + if (bundle[i].state == BUNDLEUNDEF) + ++config->cluster_undefined_bundles; + } + // Clear out defined tunnels, counting the number of // undefs remaining. config->cluster_undefined_tunnels = 0; @@ -726,9 +764,9 @@ static void cluster_check_sessions(int highsession, int freesession_ptr, int hig } - if (config->cluster_undefined_sessions || config->cluster_undefined_tunnels) { - LOG(2, 0, 0, "Cleared undefined sessions/tunnels. %d sess (high %d), %d tunn (high %d)\n", - config->cluster_undefined_sessions, highsession, config->cluster_undefined_tunnels, hightunnel); + if (config->cluster_undefined_sessions || config->cluster_undefined_tunnels || config->cluster_undefined_bundles) { + LOG(2, 0, 0, "Cleared undefined sessions/bundles/tunnels. %d sess (high %d), %d bund (high %d), %d tunn (high %d)\n", + config->cluster_undefined_sessions, highsession, config->cluster_undefined_bundles, highbundle, config->cluster_undefined_tunnels, hightunnel); return; } @@ -738,7 +776,7 @@ static void cluster_check_sessions(int highsession, int freesession_ptr, int hig cluster_uptodate(); } -static int hb_add_type(char **p, int type, int id) +static int hb_add_type(uint8_t **p, int type, int id) { switch (type) { case C_CSESSION: { // Compressed C_SESSION. @@ -752,13 +790,34 @@ static int hb_add_type(char **p, int type, int id) // Did we compress the full structure, and is the size actually // reduced?? if ( (d - orig) == sizeof(sessiont) && size < sizeof(sessiont) ) { - add_type(p, C_CSESSION, id, (char *) c, size); + add_type(p, C_CSESSION, id, c, size); break; } // Failed to compress : Fall through. } - case C_SESSION: add_type(p, C_SESSION, id, - (char *) &session[id], sizeof(sessiont)); + case C_SESSION: + add_type(p, C_SESSION, id, (uint8_t *) &session[id], sizeof(sessiont)); + break; + + case C_CBUNDLE: { // Compressed C_BUNDLE + uint8_t c[sizeof(bundlet) * 2]; // Bigger than worst case. + uint8_t *d = (uint8_t *) &bundle[id]; + uint8_t *orig = d; + int size; + + size = rle_compress( &d, sizeof(bundlet), c, sizeof(c) ); + + // Did we compress the full structure, and is the size actually + // reduced?? + if ( (d - orig) == sizeof(bundlet) && size < sizeof(bundlet) ) { + add_type(p, C_CBUNDLE, id, c, size); + break; + } + // Failed to compress : Fall through. + } + + case C_BUNDLE: + add_type(p, C_BUNDLE, id, (uint8_t *) &bundle[id], sizeof(bundlet)); break; case C_CTUNNEL: { // Compressed C_TUNNEL @@ -777,8 +836,8 @@ static int hb_add_type(char **p, int type, int id) } // Failed to compress : Fall through. } - case C_TUNNEL: add_type(p, C_TUNNEL, id, - (char *) &tunnel[id], sizeof(tunnelt)); + case C_TUNNEL: + add_type(p, C_TUNNEL, id, (uint8_t *) &tunnel[id], sizeof(tunnelt)); break; default: LOG(0, 0, 0, "Found an invalid type in heart queue! (%d)\n", type); @@ -793,10 +852,10 @@ static int hb_add_type(char **p, int type, int id) // void cluster_heartbeat() { - int i, count = 0, tcount = 0; - char buff[MAX_HEART_SIZE + sizeof(heartt) + sizeof(int) ]; + int i, count = 0, tcount = 0, bcount = 0; + uint8_t buff[MAX_HEART_SIZE + sizeof(heartt) + sizeof(int) ]; heartt h; - char *p = buff; + uint8_t *p = buff; if (!config->cluster_iam_master) // Only the master does this. return; @@ -814,13 +873,15 @@ void cluster_heartbeat() h.highsession = config->cluster_highest_sessionid; h.freesession = sessionfree; h.hightunnel = config->cluster_highest_tunnelid; + h.highbundle = config->cluster_highest_bundleid; h.size_sess = sizeof(sessiont); // Just in case. + h.size_bund = sizeof(bundlet); h.size_tunn = sizeof(tunnelt); h.interval = config->cluster_hb_interval; h.timeout = config->cluster_hb_timeout; h.table_version = config->cluster_table_version; - add_type(&p, C_HEARTBEAT, HB_VERSION, (char *) &h, sizeof(h)); + add_type(&p, C_HEARTBEAT, HB_VERSION, (uint8_t *) &h, sizeof(h)); for (i = 0; i < config->cluster_num_changes; ++i) { hb_add_type(&p, cluster_changes[i].type, cluster_changes[i].id); @@ -869,6 +930,22 @@ void cluster_heartbeat() ++tcount; } + // + // Fill out the packet with bundles from the bundle table... + while ( (p + sizeof(uint32_t) * 2 + sizeof(bundlet) ) < (buff + MAX_HEART_SIZE) ) { + + if (!walk_bundle_number) // bundle #0 isn't valid. + ++walk_bundle_number; + + if (bcount >= config->cluster_highest_bundleid) + break; + + hb_add_type(&p, C_CTUNNEL, walk_bundle_number); + walk_tunnel_number = (1+walk_bundle_number)%(config->cluster_highest_bundleid+1); // +1 avoids divide by zero. + + ++bcount; + } + // // Did we do something wrong? if (p > (buff + sizeof(buff))) { // Did we somehow manage to overun the buffer? @@ -878,9 +955,9 @@ void cluster_heartbeat() } LOG(3, 0, 0, "Sending v%d heartbeat #%d, change #%" PRIu64 " with %d changes " - "(%d x-sess, %d x-tunnels, %d highsess, %d hightun, size %d)\n", + "(%d x-sess, %d x-bundles, %d x-tunnels, %d highsess, %d highbund, %d hightun, size %d)\n", HB_VERSION, h.seq, h.table_version, config->cluster_num_changes, - count, tcount, config->cluster_highest_sessionid, + count, bcount, tcount, config->cluster_highest_sessionid, config->cluster_highest_bundleid, config->cluster_highest_tunnelid, (int) (p - buff)); config->cluster_num_changes = 0; @@ -929,6 +1006,17 @@ int cluster_send_session(int sid) return type_changed(C_CSESSION, sid); } +// A particular bundle has been changed! +int cluster_send_bundle(int bid) +{ + if (!config->cluster_iam_master) { + LOG(0, 0, bid, "I'm not a master, but I just tried to change a bundle!\n"); + return -1; + } + + return type_changed(C_CBUNDLE, bid); +} + // A particular tunnel has been changed! int cluster_send_tunnel(int tid) { @@ -1099,7 +1187,7 @@ static int cluster_set_master(in_addr_t peer, in_addr_t master) // Note that we don't mark the session as dirty; We rely on // the slow table walk to propogate this back out to the slaves. // -static int cluster_handle_bytes(char *data, int size) +static int cluster_handle_bytes(uint8_t *data, int size) { bytest *b; @@ -1166,6 +1254,31 @@ static int cluster_recv_session(int more, uint8_t *p) return 0; } +static int cluster_recv_bundle(int more, uint8_t *p) +{ + if (more >= MAXBUNDLE) { + LOG(0, 0, 0, "DANGER: Received a bundle id > MAXBUNDLE!\n"); + return -1; + } + + if (bundle[more].state == BUNDLEUNDEF) { + if (config->cluster_iam_uptodate) { // Sanity. + LOG(0, 0, 0, "I thought I was uptodate but I just found an undefined bundle!\n"); + } else { + --config->cluster_undefined_bundles; + } + } + + memcpy(&bundle[more], p, sizeof(bundle[more]) ); + + LOG(5, 0, more, "Received bundle update\n"); + + if (!config->cluster_iam_uptodate) + cluster_uptodate(); // Check to see if we're up to date. + + return 0; +} + static int cluster_recv_tunnel(int more, uint8_t *p) { if (more >= MAXTUNNEL) { @@ -1238,6 +1351,9 @@ struct oldsession { uint32_t tx_connect_speed; uint32_t rx_connect_speed; uint32_t flags; +#define SF_IPCP_ACKED 1 // Has this session seen an IPCP Ack? +#define SF_LCP_ACKED 2 // LCP negotiated +#define SF_CCP_ACKED 4 // CCP negotiated in_addr_t snoop_ip; uint16_t snoop_port; uint16_t sid; @@ -1256,13 +1372,10 @@ static uint8_t *convert_session(struct oldsession *old) new.next = old->next; new.far = old->far; new.tunnel = old->tunnel; - new.l2tp_flags = old->l2tp_flags; - new.flags = old->flags; + new.flags = old->l2tp_flags; new.ip = old->ip; new.ip_pool_index = old->ip_pool_index; new.unique_id = old->unique_id; - new.nr = old->nr; - new.ns = old->ns; new.magic = old->magic; new.pin = old->pin; new.pout = old->pout; @@ -1297,6 +1410,21 @@ static uint8_t *convert_session(struct oldsession *old) for (i = 0; i < MAXROUTE; i++) memcpy(&new.route[i], &old->route[i], sizeof(new.route[i])); + if (new.opened) + { + new.ppp.phase = Establish; + if (old->flags & (SF_IPCP_ACKED|SF_LCP_ACKED)) + { + new.ppp.phase = Network; + new.ppp.lcp = Opened; + new.ppp.ipcp = (old->flags & SF_IPCP_ACKED) ? Opened : Starting; + new.ppp.ccp = (old->flags & SF_CCP_ACKED) ? Opened : Stopped; + } + + // no PPPv6 in old session + new.ppp.ipv6cp = Stopped; + } + return (uint8_t *) &new; } @@ -1437,7 +1565,7 @@ static int cluster_process_heartbeat(uint8_t *data, int size, int more, uint8_t // Check that we don't have too many undefined sessions, and // that the free session pointer is correct. - cluster_check_sessions(h->highsession, h->freesession, h->hightunnel); + cluster_check_sessions(h->highsession, h->freesession, h->highbundle, h->hightunnel); if (h->interval != config->cluster_hb_interval) { @@ -1527,7 +1655,7 @@ static int cluster_process_heartbeat(uint8_t *data, int size, int more, uint8_t s -= (p - orig_p); if (size != sizeof(tunnelt) ) { // Ouch! Very very bad! - LOG(0, 0, 0, "DANGER: Received a CSESSION that didn't decompress correctly!\n"); + LOG(0, 0, 0, "DANGER: Received a CTUNNEL that didn't decompress correctly!\n"); // Now what? Should exit! No-longer up to date! break; } @@ -1545,6 +1673,34 @@ static int cluster_process_heartbeat(uint8_t *data, int size, int more, uint8_t p += sizeof(tunnel[more]); s -= sizeof(tunnel[more]); break; + + case C_CBUNDLE: { // Compressed bundle structure. + uint8_t c[ sizeof(bundlet) + 2]; + int size; + uint8_t *orig_p = p; + + size = rle_decompress((uint8_t **) &p, s, c, sizeof(c)); + s -= (p - orig_p); + + if (size != sizeof(bundlet) ) { // Ouch! Very very bad! + LOG(0, 0, 0, "DANGER: Received a CBUNDLE that didn't decompress correctly!\n"); + // Now what? Should exit! No-longer up to date! + break; + } + + cluster_recv_bundle(more, c); + break; + + } + case C_BUNDLE: + if ( s < sizeof(bundle[more])) + goto shortpacket; + + cluster_recv_bundle(more, p); + + p += sizeof(bundle[more]); + s -= sizeof(bundle[more]); + break; default: LOG(0, 0, 0, "DANGER: I received a heartbeat element where I didn't understand the type! (%d)\n", type); return -1; // can't process any more of the packet!! @@ -1572,10 +1728,10 @@ shortpacket: // We got a packet on the cluster port! // Handle pings, lastseens, and heartbeats! // -int processcluster(char *data, int size, in_addr_t addr) +int processcluster(uint8_t *data, int size, in_addr_t addr) { int type, more; - char *p = data; + uint8_t *p = data; int s = size; if (addr == my_address) @@ -1631,7 +1787,11 @@ int processcluster(char *data, int size, in_addr_t addr) STAT(recv_forward); if (type == C_FORWARD_DAE) - processdae(p, s, &a, sizeof(a)); + { + struct in_addr local; + local.s_addr = config->bind_address ? config->bind_address : my_address; + processdae(p, s, &a, sizeof(a), &local); + } else processudp(p, s, &a); @@ -1726,11 +1886,13 @@ int cmd_show_cluster(struct cli_def *cli, char *command, char **argv, int argc) cli_print(cli, "Table version # : %" PRIu64, config->cluster_table_version); cli_print(cli, "Next sequence number expected: %d", config->cluster_seq_number); cli_print(cli, "%d sessions undefined of %d", config->cluster_undefined_sessions, config->cluster_highest_sessionid); + cli_print(cli, "%d bundles undefined of %d", config->cluster_undefined_bundles, config->cluster_highest_bundleid); cli_print(cli, "%d tunnels undefined of %d", config->cluster_undefined_tunnels, config->cluster_highest_tunnelid); } else { cli_print(cli, "Table version # : %" PRIu64, config->cluster_table_version); cli_print(cli, "Next heartbeat # : %d", config->cluster_seq_number); cli_print(cli, "Highest session : %d", config->cluster_highest_sessionid); + cli_print(cli, "Highest bundle : %d", config->cluster_highest_bundleid); cli_print(cli, "Highest tunnel : %d", config->cluster_highest_tunnelid); cli_print(cli, "%d changes queued for sending", config->cluster_num_changes); } @@ -1814,7 +1976,7 @@ static int rle_decompress(uint8_t **src_p, int ssize, uint8_t *dst, int dsize) { int count; int orig_dsize = dsize; - char *src = *src_p; + uint8_t *src = *src_p; while (ssize >0 && dsize > 0) { // While there's more to decompress, and there's room in the decompress buffer... count = *src++; --ssize; // get the count byte from the source.