summaryrefslogtreecommitdiff
path: root/src/master/servers.c
diff options
context:
space:
mode:
authorPaweł Redman <pawel.redman@gmail.com>2017-03-22 17:56:34 +0100
committerPaweł Redman <pawel.redman@gmail.com>2017-03-22 17:56:34 +0100
commit6a777afc079c2a8d3af3ecd2145fe8dd50567a39 (patch)
tree520f4489cebf8564ef6cb27064ceea45cbc005b3 /src/master/servers.c
Funko sources as released by Rotacak.HEADmaster
Diffstat (limited to 'src/master/servers.c')
-rw-r--r--src/master/servers.c666
1 files changed, 666 insertions, 0 deletions
diff --git a/src/master/servers.c b/src/master/servers.c
new file mode 100644
index 0000000..a8412a1
--- /dev/null
+++ b/src/master/servers.c
@@ -0,0 +1,666 @@
+/*
+ servers.c
+
+ Server list and address mapping management for dpmaster
+
+ Copyright (C) 2004 Mathieu Olivier
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+*/
+
+
+#include "common.h"
+#include "servers.h"
+
+
+// ---------- Constants ---------- //
+
+// Address hash bitmask
+#define HASH_BITMASK (hash_table_size - 1)
+
+
+// ---------- Variables ---------- //
+
+// All server structures are allocated in one block in the "servers" array.
+// Each used slot is also part of a linked list in "hash_table". A simple
+// hash of the address and port of a server gives its index in the table.
+static server_t* servers = NULL;
+static size_t max_nb_servers = DEFAULT_MAX_NB_SERVERS;
+static size_t nb_servers = 0;
+static server_t** hash_table = NULL;
+static size_t hash_table_size = (1 << DEFAULT_HASH_SIZE);
+
+// Last allocated entry in the "servers" array.
+// Used as a start index for finding a free slot in "servers" more quickly
+static unsigned int last_alloc;
+
+// Variables for Sv_GetFirst, Sv_GetNext and Sv_RemoveCurrentAndGetNext
+static server_t* crt_server = NULL;
+static server_t** prev_pointer = NULL;
+static int crt_hash_ind = -1;
+
+// List of address mappings. They are sorted by "from" field (IP, then port)
+static addrmap_t* addrmaps = NULL;
+
+
+// ---------- Private functions ---------- //
+
+/*
+====================
+Sv_AddressHash
+
+Compute the hash of a server address
+====================
+*/
+static unsigned int Sv_AddressHash (const struct sockaddr_in* address)
+{
+ qbyte* addr = (qbyte*)&address->sin_addr.s_addr;
+ qbyte* port = (qbyte*)&address->sin_port;
+ qbyte hash;
+
+ hash = addr[0] ^ addr[1] ^ addr[2] ^ addr[3] ^ port[0] ^ port[1];
+ return hash & HASH_BITMASK;
+}
+
+
+/*
+====================
+Sv_RemoveAndGetNextPtr
+
+Remove a server from the list and returns its "next" pointer
+====================
+*/
+static server_t* Sv_RemoveAndGetNextPtr (server_t* sv, server_t** prev)
+{
+ nb_servers--;
+ MsgPrint (MSG_NORMAL,
+ "%s:%hu timed out; %u servers currently registered\n",
+ inet_ntoa (sv->address.sin_addr), ntohs (sv->address.sin_port),
+ nb_servers);
+
+ // Mark this structure as "free"
+ sv->active = qfalse;
+
+ *prev = sv->next;
+ return sv->next;
+}
+
+
+/*
+====================
+Sv_ResolveAddr
+
+Resolve an internet address
+name may include a port number, after a ':'
+====================
+*/
+static qboolean Sv_ResolveAddr (const char* name, struct sockaddr_in* addr)
+{
+ char *namecpy, *port;
+ struct hostent* host;
+
+ // Create a work copy
+ namecpy = strdup (name);
+ if (namecpy == NULL)
+ {
+ MsgPrint (MSG_ERROR,
+ "ERROR: can't allocate enough memory to resolve %s\n",
+ name);
+ return qfalse;
+ }
+
+ // Find the port in the address
+ port = strchr (namecpy, ':');
+ if (port != NULL)
+ *port++ = '\0';
+
+ // Resolve the address
+ host = gethostbyname (namecpy);
+ if (host == NULL)
+ {
+ MsgPrint (MSG_ERROR, "ERROR: can't resolve %s\n", namecpy);
+ free (namecpy);
+ return qfalse;
+ }
+ if (host->h_addrtype != AF_INET)
+ {
+ MsgPrint (MSG_ERROR, "ERROR: %s is not an IPv4 address\n",
+ namecpy);
+ free (namecpy);
+ return qfalse;
+ }
+
+ // Build the structure
+ memset (addr, 0, sizeof (*addr));
+ addr->sin_family = AF_INET;
+ memcpy (&addr->sin_addr.s_addr, host->h_addr,
+ sizeof (addr->sin_addr.s_addr));
+ if (port != NULL)
+ addr->sin_port = htons ((unsigned short)atoi (port));
+
+ MsgPrint (MSG_DEBUG, "\"%s\" resolved to %s:%hu\n",
+ name, inet_ntoa (addr->sin_addr), ntohs (addr->sin_port));
+
+ free (namecpy);
+ return qtrue;
+}
+
+
+/*
+====================
+Sv_InsertAddrmapIntoList
+
+Insert an addrmap structure to the addrmaps list
+====================
+*/
+static void Sv_InsertAddrmapIntoList (addrmap_t* new_map)
+{
+ addrmap_t* addrmap = addrmaps;
+ addrmap_t** prev = &addrmaps;
+
+ // Stop at the end of the list, or if the addresses become too high
+ while (addrmap != NULL &&
+ addrmap->from.sin_addr.s_addr <= new_map->from.sin_addr.s_addr)
+ {
+ // If we found the right place
+ if (addrmap->from.sin_addr.s_addr == new_map->from.sin_addr.s_addr &&
+ addrmap->from.sin_port >= new_map->from.sin_port)
+ {
+ // If a mapping is already recorded for this address
+ if (addrmap->from.sin_port == new_map->from.sin_port)
+ {
+ MsgPrint (MSG_WARNING,
+ "WARNING: Address %s:%hu has several mappings\n",
+ inet_ntoa (new_map->from.sin_addr),
+ ntohs (new_map->from.sin_port));
+
+ *prev = addrmap->next;
+ free (addrmap);
+ }
+ break;
+ }
+
+ prev = &addrmap->next;
+ addrmap = addrmap->next;
+ }
+
+ // Insert it
+ new_map->next = *prev;
+ *prev = new_map;
+
+ MsgPrint (MSG_NORMAL, "Address \"%s\" mapped to \"%s\" (%s:%hu)\n",
+ new_map->from_string, new_map->to_string,
+ inet_ntoa (new_map->to.sin_addr), ntohs (new_map->to.sin_port));
+}
+
+
+/*
+====================
+Sv_GetAddrmap
+
+Look for an address mapping corresponding to addr
+====================
+*/
+static const addrmap_t* Sv_GetAddrmap (const struct sockaddr_in* addr)
+{
+ const addrmap_t* addrmap = addrmaps;
+ const addrmap_t* found = NULL;
+
+ // Stop at the end of the list, or if the addresses become too high
+ while (addrmap != NULL &&
+ addrmap->from.sin_addr.s_addr <= addr->sin_addr.s_addr)
+ {
+ // If it's the right address
+ if (addrmap->from.sin_addr.s_addr == addr->sin_addr.s_addr)
+ {
+ // If the exact mapping isn't there
+ if (addrmap->from.sin_port > addr->sin_port)
+ return found;
+
+ // If we found the exact address
+ if (addrmap->from.sin_port == addr->sin_port)
+ return addrmap;
+
+ // General mapping
+ // Store it in case we don't find the exact address mapping
+ if (addrmap->from.sin_port == 0)
+ found = addrmap;
+ }
+
+ addrmap = addrmap->next;
+ }
+
+ return found;
+}
+
+
+/*
+====================
+Sv_ResolveAddrmap
+
+Resolve an addrmap structure and check the parameters validity
+====================
+*/
+static qboolean Sv_ResolveAddrmap (addrmap_t* addrmap)
+{
+ // Resolve the addresses
+ if (!Sv_ResolveAddr (addrmap->from_string, &addrmap->from) ||
+ !Sv_ResolveAddr (addrmap->to_string, &addrmap->to))
+ return qfalse;
+
+ // 0.0.0.0 addresses are forbidden
+ if (addrmap->from.sin_addr.s_addr == 0 ||
+ addrmap->to.sin_addr.s_addr == 0)
+ {
+ MsgPrint (MSG_ERROR,
+ "ERROR: Mapping from or to 0.0.0.0 is forbidden\n");
+ return qfalse;
+ }
+
+ // Do NOT allow mapping to loopback addresses
+ if ((ntohl (addrmap->to.sin_addr.s_addr) >> 24) == 127)
+ {
+ MsgPrint (MSG_ERROR,
+ "ERROR: Mapping to a loopback address is forbidden\n");
+ return qfalse;
+ }
+
+ return qtrue;
+}
+
+
+/*
+====================
+Sv_IsActive
+
+Return qtrue if a server is active.
+Test if the server has timed out and remove it if it's the case.
+====================
+*/
+static qboolean Sv_IsActive (server_t* server)
+{
+
+ // If the entry isn't even used
+ if (! server->active)
+ return qfalse;
+
+ // If the server has timed out
+ if (server->timeout < crt_time)
+ {
+ unsigned int hash;
+ server_t **prev, *sv;
+
+ hash = Sv_AddressHash (&server->address);
+ prev = &hash_table[hash];
+ sv = hash_table[hash];
+
+ while (sv != server)
+ {
+ prev = &sv->next;
+ sv = sv->next;
+ }
+
+ Sv_RemoveAndGetNextPtr (sv, prev);
+ return qfalse;
+ }
+
+ return qtrue;
+}
+
+
+// ---------- Public functions (servers) ---------- //
+
+/*
+====================
+Sv_SetHashSize
+
+Set a new hash size value
+====================
+*/
+qboolean Sv_SetHashSize (unsigned int size)
+{
+ // Too late?
+ if (hash_table != NULL)
+ return qfalse;
+
+ // Too big?
+ if (size > MAX_HASH_SIZE)
+ return qfalse;
+
+ hash_table_size = 1 << size;
+ return qtrue;
+}
+
+
+/*
+====================
+Sv_SetMaxNbServers
+
+Set a new hash size value
+====================
+*/
+qboolean Sv_SetMaxNbServers (unsigned int nb)
+{
+ // Too late?
+ if (servers != NULL)
+ return qfalse;
+
+ max_nb_servers = nb;
+ return qtrue;
+}
+
+
+/*
+====================
+Sv_Init
+
+Initialize the server list and hash table
+====================
+*/
+qboolean Sv_Init (void)
+{
+ size_t array_size;
+
+ // Allocate "servers" and clean it
+ array_size = max_nb_servers * sizeof (servers[0]);
+ servers = malloc (array_size);
+ if (!servers)
+ {
+ MsgPrint (MSG_ERROR,
+ "ERROR: can't allocate the servers array (%s)\n",
+ strerror (errno));
+ return qfalse;
+ }
+ last_alloc = max_nb_servers - 1;
+ memset (servers, 0, array_size);
+ MsgPrint (MSG_NORMAL, "%u server records allocated\n", max_nb_servers);
+
+ // Allocate "hash_table" and clean it
+ array_size = hash_table_size * sizeof (hash_table[0]);
+ hash_table = malloc (array_size);
+ if (!hash_table)
+ {
+ MsgPrint (MSG_ERROR, "ERROR: can't allocate the hash table (%s)\n",
+ strerror (errno));
+ free (servers);
+ return qfalse;
+ }
+ memset (hash_table, 0, array_size);
+ MsgPrint (MSG_NORMAL,
+ "Hash table allocated (%u entries)\n", hash_table_size);
+
+ return qtrue;
+}
+
+
+/*
+====================
+Sv_GetByAddr
+
+Search for a particular server in the list; add it if necessary
+====================
+*/
+server_t* Sv_GetByAddr (const struct sockaddr_in* address, qboolean add_it)
+{
+ server_t **prev, *sv;
+ unsigned int hash;
+ const addrmap_t* addrmap = Sv_GetAddrmap (address);
+ unsigned int startpt;
+
+ // Allow servers on a loopback address ONLY if a mapping is defined for them
+ if ((ntohl (address->sin_addr.s_addr) >> 24) == 127 && addrmap == NULL)
+ {
+ MsgPrint (MSG_WARNING,
+ "WARNING: server %s isn't allowed (loopback address)\n",
+ peer_address);
+ return NULL;
+ }
+
+ hash = Sv_AddressHash (address);
+ prev = &hash_table[hash];
+ sv = hash_table[hash];
+
+ while (sv != NULL)
+ {
+ // We check the timeout values while browsing this list
+ if (sv->timeout < crt_time)
+ {
+ sv = Sv_RemoveAndGetNextPtr (sv, prev);
+ continue;
+ }
+
+ // Found!
+ if (sv->address.sin_addr.s_addr == address->sin_addr.s_addr &&
+ sv->address.sin_port == address->sin_port)
+ {
+ // Put it on top of the list (it's useful because heartbeats
+ // are almost always followed by infoResponses)
+ *prev = sv->next;
+ sv->next = hash_table[hash];
+ hash_table[hash] = sv;
+
+ return sv;
+ }
+
+ prev = &sv->next;
+ sv = sv->next;
+ }
+
+ if (! add_it)
+ return NULL;
+
+ // Look for the first free entry in "servers"
+ startpt = last_alloc;
+ for (;;)
+ {
+ last_alloc = (last_alloc + 1) % max_nb_servers;
+
+ // Free entry found?
+ if (!Sv_IsActive (&servers[last_alloc]))
+ break;
+
+ // No more room
+ if (last_alloc == startpt)
+ return NULL;
+ }
+ sv = &servers[last_alloc];
+
+ // Initialize the structure
+ memset (sv, 0, sizeof (*sv));
+ memcpy (&sv->address, address, sizeof (sv->address));
+ sv->addrmap = addrmap;
+
+ // Add it to the list it belongs to
+ sv->next = hash_table[hash];
+ hash_table[hash] = sv;
+ nb_servers++;
+
+ MsgPrint (MSG_NORMAL,
+ "New server added: %s; %u servers are currently registered\n",
+ peer_address, nb_servers);
+ MsgPrint (MSG_DEBUG,
+ " - index: %u\n"
+ " - hash: 0x%02X\n",
+ last_alloc, hash);
+
+ return sv;
+}
+
+
+/*
+====================
+Sv_GetFirst
+
+Get the first server in the list
+====================
+*/
+server_t* Sv_GetFirst (void)
+{
+ crt_server = NULL;
+ prev_pointer = NULL;
+ crt_hash_ind = -1;
+
+ return Sv_GetNext ();
+}
+
+
+/*
+====================
+Sv_GetNext
+
+Get the next server in the list
+====================
+*/
+server_t* Sv_GetNext (void)
+{
+ for (;;)
+ {
+ // If there is a current server, follow the link
+ if (crt_server != NULL)
+ {
+ prev_pointer = &crt_server->next;
+ crt_server = crt_server->next;
+ }
+
+ // If we don't have the next server yet
+ if (crt_server == NULL)
+ {
+ // Search the hash table for the next server
+ while (crt_hash_ind < (int)(hash_table_size - 1))
+ {
+ crt_hash_ind++;
+
+ if (hash_table[crt_hash_ind] != NULL)
+ {
+ crt_server = hash_table[crt_hash_ind];
+ prev_pointer = &hash_table[crt_hash_ind];
+ break;
+ }
+ }
+ }
+
+ // Did we hit the end of the list?
+ if (crt_server == NULL)
+ return NULL;
+
+ // If the new current server has timed out, remove it
+ if (crt_server->timeout < crt_time)
+ crt_server = Sv_RemoveAndGetNextPtr (crt_server, prev_pointer);
+ else
+ return crt_server;
+ }
+}
+
+
+// ---------- Public functions (address mappings) ---------- //
+
+/*
+====================
+Sv_AddAddressMapping
+
+Add an unresolved address mapping to the list
+mapping must be of the form "addr1:port1=addr2:port2", ":portX" are optional
+====================
+*/
+qboolean Sv_AddAddressMapping (const char* mapping)
+{
+ char *map_string, *to_ip;
+ addrmap_t* addrmap;
+
+ // Get a working copy of the mapping string
+ map_string = strdup (mapping);
+ if (map_string == NULL)
+ {
+ MsgPrint (MSG_ERROR,
+ "ERROR: can't allocate address mapping string\n");
+ return qfalse;
+ }
+
+ // Find the '='
+ to_ip = strchr (map_string, '=');
+ if (to_ip == NULL)
+ {
+ MsgPrint (MSG_ERROR,
+ "ERROR: invalid syntax in address mapping string\n");
+ free (map_string);
+ return qfalse;
+ }
+ *to_ip++ = '\0';
+
+ // Allocate the structure
+ addrmap = malloc (sizeof (*addrmap));
+ if (addrmap == NULL)
+ {
+ MsgPrint (MSG_ERROR,
+ "ERROR: can't allocate address mapping structure\n");
+ free (map_string);
+ return qfalse;
+ }
+ memset (addrmap, 0, sizeof (*addrmap));
+ addrmap->from_string = strdup (map_string);
+ addrmap->to_string = strdup (to_ip);
+ if (addrmap->from_string == NULL || addrmap->to_string == NULL)
+ {
+ MsgPrint (MSG_ERROR,
+ "ERROR: can't allocate address mapping strings\n");
+ free (addrmap->to_string);
+ free (addrmap->from_string);
+ free (map_string);
+ return qfalse;
+ }
+
+ // Add it on top of "addrmaps"
+ addrmap->next = addrmaps;
+ addrmaps = addrmap;
+
+ return qtrue;
+}
+
+
+/*
+====================
+Sv_ResolveAddressMappings
+
+Resolve the address mapping list
+====================
+*/
+qboolean Sv_ResolveAddressMappings (void)
+{
+ addrmap_t* unresolved = addrmaps;
+ addrmap_t* addrmap;
+ qboolean succeeded = qtrue;
+
+ addrmaps = NULL;
+
+ while (unresolved != NULL)
+ {
+ // Remove it from the unresolved list
+ addrmap = unresolved;
+ unresolved = unresolved->next;
+
+ // Continue the resolution, even if there's an error
+ if (!Sv_ResolveAddrmap (addrmap))
+ {
+ free (addrmap->from_string);
+ free (addrmap->to_string);
+ free (addrmap);
+ succeeded = qfalse;
+ }
+ else
+ Sv_InsertAddrmapIntoList (addrmap);
+ }
+
+ return succeeded;
+}