name mode size
..
config 040000
doc 040000
Makefile 100644 372B
README 100644 27.44kB
address.c 100644 11.01kB
address.h 100644 2.29kB
hash.c 100644 14.99kB
hash.h 100644 5.97kB
mi.c 100644 4.87kB
mi.h 100644 1.61kB
parse_config.c 100644 6.05kB
parse_config.h 100644 1.01kB
permissions.c 100644 24.61kB
permissions.h 100644 2.45kB
rule.c 100644 3.86kB
rule.h 100644 2.06kB
trusted.c 100644 12.65kB
trusted.h 100644 2.25kB
README
permissions Module Miklos Tirpak Edited by Miklos Tirpak Edited by Bogdan-Andrei Iancu Edited by Juha Heinanen Copyright © 2003 Miklos Tirpak Copyright © 2006-2008 Juha Heinanen __________________________________________________________________ Table of Contents 1. Admin Guide 1. Overview 1.1. Call Routing 1.2. Registration Permissions 1.3. URI Permissions 1.4. Address Permissions 1.5. Trusted Requests 2. Dependencies 2.1. Kamailio Modules 2.2. External Libraries or Applications 3. Parameters 3.1. default_allow_file (string) 3.2. default_deny_file (string) 3.3. check_all_branches (integer) 3.4. allow_suffix (string) 3.5. deny_suffix (string) 3.6. db_url (string) 3.7. address_table (string) 3.8. grp_col (string) 3.9. ip_addr_col (string) 3.10. mask_col (string) 3.11. port_col (string) 3.12. db_mode (integer) 3.13. trusted_table (string) 3.14. source_col (string) 3.15. proto_col (string) 3.16. from_col (string) 3.17. tag_col (string) 3.18. peer_tag_avp (AVP string) 3.19. peer_tag_mode (integer) 4. Functions 4.1. allow_routing() 4.2. allow_routing(basename) 4.3. allow_routing(allow_file,deny_file) 4.4. allow_register(basename) 4.5. allow_register(allow_file, deny_file) 4.6. allow_uri(basename, pvar) 4.7. allow_address(group_id, ip_addr_pvar, port_pvar) 4.8. allow_source_address([group_id]) 4.9. allow_source_address_group() 4.10. allow_trusted([src_ip_pvar, proto_pvar]) 5. MI Commands 5.1. address_reload 5.2. address_dump 5.3. subnet_dump 5.4. trusted_reload 5.5. trusted_dump 5.6. allow_uri List of Examples 1.1. Set default_allow_file parameter 1.2. Set default_deny_file parameter 1.3. Set check_all_branches parameter 1.4. Set allow_suffix parameter 1.5. Set deny_suffix parameter 1.6. Set db_url parameter 1.7. Set address_table parameter 1.8. Set grp_col parameter 1.9. Set ip_addr_col parameter 1.10. Set mask_col parameter 1.11. Set port_col parameter 1.12. Set db_mode parameter 1.13. Set trusted_table parameter 1.14. Set source_col parameter 1.15. Set proto_col parameter 1.16. Set from_col parameter 1.17. Set tag_col parameter 1.18. Set peer_tag_avp parameter 1.19. Set peer_tag_mode parameter 1.20. allow_routing usage 1.21. allow_routing(basename) usage 1.22. allow_routing(allow_file, deny_file) usage 1.23. allow_register(basename) usage 1.24. allow_register(allow_file, deny_file) usage 1.25. allow_uri(basename, pvar) usage 1.26. allow_address() usage 1.27. allow_source_address(group_id) usage 1.28. allow_source_address_group() usage 1.29. allow_trusted() usage Chapter 1. Admin Guide Table of Contents 1. Overview 1.1. Call Routing 1.2. Registration Permissions 1.3. URI Permissions 1.4. Address Permissions 1.5. Trusted Requests 2. Dependencies 2.1. Kamailio Modules 2.2. External Libraries or Applications 3. Parameters 3.1. default_allow_file (string) 3.2. default_deny_file (string) 3.3. check_all_branches (integer) 3.4. allow_suffix (string) 3.5. deny_suffix (string) 3.6. db_url (string) 3.7. address_table (string) 3.8. grp_col (string) 3.9. ip_addr_col (string) 3.10. mask_col (string) 3.11. port_col (string) 3.12. db_mode (integer) 3.13. trusted_table (string) 3.14. source_col (string) 3.15. proto_col (string) 3.16. from_col (string) 3.17. tag_col (string) 3.18. peer_tag_avp (AVP string) 3.19. peer_tag_mode (integer) 4. Functions 4.1. allow_routing() 4.2. allow_routing(basename) 4.3. allow_routing(allow_file,deny_file) 4.4. allow_register(basename) 4.5. allow_register(allow_file, deny_file) 4.6. allow_uri(basename, pvar) 4.7. allow_address(group_id, ip_addr_pvar, port_pvar) 4.8. allow_source_address([group_id]) 4.9. allow_source_address_group() 4.10. allow_trusted([src_ip_pvar, proto_pvar]) 5. MI Commands 5.1. address_reload 5.2. address_dump 5.3. subnet_dump 5.4. trusted_reload 5.5. trusted_dump 5.6. allow_uri 1. Overview 1.1. Call Routing 1.2. Registration Permissions 1.3. URI Permissions 1.4. Address Permissions 1.5. Trusted Requests 1.1. Call Routing The module can be used to determine if a call has appropriate permission to be established. Permission rules are stored in plaintext configuration files similar to hosts.allow and hosts.deny files used by tcpd. When allow_routing function is called it tries to find a rule that matches selected fields of the message. Kamailio is a forking proxy and therefore a single message can be sent to different destinations simultaneously. When checking permissions all the destinations must be checked and if one of them fails, the forwarding will fail. The matching algorithm is as follows, first match wins: * Create a set of pairs of form (From, R-URI of branch 1), (From, R-URI of branch 2), etc. * Routing will be allowed when all pairs match an entry in the allow file. * Otherwise routing will be denied when one of pairs matches an entry in the deny file. * Otherwise, routing will be allowed. A non-existing permission control file is treated as if it were an empty file. Thus, permission control can be turned off by providing no permission control files. From header field and Request-URIs are always compared with regular expressions! For the syntax see the sample file: config/permissions.allow. 1.2. Registration Permissions In addition to call routing it is also possible to check REGISTER messages and decide--based on the configuration files--whether the message should be allowed and the registration accepted or not. Main purpose of the function is to prevent registration of "prohibited" IP addresses. One example, when a malicious user registers a contact containing IP address of a PSTN gateway, he might be able to bypass authorization checks performed by the SIP proxy. That is undesirable and therefore attempts to register IP address of a PSTN gateway should be rejected. Files config/register.allow and config/register.deny contain an example configuration. Function for registration checking is called allow_register and the algorithm is very similar to the algorithm described in Section 1.1, “Call Routing”. The only difference is in the way how pairs are created. Instead of From header field the function uses To header field because To header field in REGISTER messages contains the URI of the person being registered. Instead of the Request-URI of branches the function uses Contact header field. Thus, pairs used in matching will look like this: (To, Contact 1), (To, Contact 2), (To, Contact 3), and so on.. The algorithm of matching is same as described in Section 1.1, “Call Routing”. 1.3. URI Permissions The module can be used to determine if request is allowed to the destination specified by an URI stored in a pvar. Permission rules are stored in plaintext configuration files similar to hosts.allow and hosts.deny used by tcpd. When allow_uri function is called, it tries to find a rule that matches selected fields of the message. The matching algorithm is as follows, first match wins: * Create a pair <From URI, URI stored in pvar>. * Request will be allowed when the pair matches an entry in the allow file. * Otherwise request will be denied when the pair matches an entry in the deny file. * Otherwise, request will be allowed. A non-existing permission control file is treated as if it were an empty file. Thus, permission control can be turned off by providing no permission control files. From URI and URI stored in pvar are always compared with regular expressions! For the syntax see the sample file: config/permissions.allow. 1.4. Address Permissions The module can be used to determine if an address (IP address and port) matches any of the IP subnets stored in cached openser database table. Port 0 in cached database table matches any port. IP address and port to be matched can be either taken from the request (allow_source_address) or given as pvar arguments (allow_address). Addresses stored in cached database table can be grouped together into one or more groups specified by a group identifier (positive integer value, i.e., equal or greater than 1). Group identifier is given as argument to allow_address and allow_source_address functions. As a side effect of matching the address, non-NULL tag (see tag_col module parameter) is added as value to peer_tag AVP if peer_tag_avp module parameter has been defined. 1.5. Trusted Requests The module can be used to determine if an incoming request can be trusted without authentication. When allow_trusted function is called, it tries to find a rule that matches the request. Rules contain the following fields: <source address, transport protocol, regular expression>. A requests is accepted if there exists a rule, where * source address is equal to source address of request or source address given in pvar, * transport protocol is either "ANY" or equal to transport protocol of request or transport protocol given in pvar, and * regular expression is either empty (NULL in database) or matches From URI of request. Otherwise the request is rejected. As a side effect of accepting the request, peer's non-NULL tag (see tag_col module parameter) is added as value to peer_tag AVP if peer_tag_avp module parameter has been defined. Rules are stored in a database table specified by module parameters. There also exists a module parameter dm_mode that determines if rules are cached into memory for faster matching or if database is consulted for each invocation of allow_trusted function call. 2. Dependencies 2.1. Kamailio Modules 2.2. External Libraries or Applications 2.1. Kamailio Modules The following modules must be loaded before this module: * No dependencies on other Kamailio modules. 2.2. External Libraries or Applications The following libraries or applications must be installed before running Kamailio with this module loaded: * None. 3. Parameters 3.1. default_allow_file (string) 3.2. default_deny_file (string) 3.3. check_all_branches (integer) 3.4. allow_suffix (string) 3.5. deny_suffix (string) 3.6. db_url (string) 3.7. address_table (string) 3.8. grp_col (string) 3.9. ip_addr_col (string) 3.10. mask_col (string) 3.11. port_col (string) 3.12. db_mode (integer) 3.13. trusted_table (string) 3.14. source_col (string) 3.15. proto_col (string) 3.16. from_col (string) 3.17. tag_col (string) 3.18. peer_tag_avp (AVP string) 3.19. peer_tag_mode (integer) 3.1. default_allow_file (string) Default allow file used by functions without parameters. If you don't specify full pathname then the directory in which is the main config file is located will be used. Default value is “permissions.allow”. Example 1.1. Set default_allow_file parameter ... modparam("permissions", "default_allow_file", "/etc/permissions.allow") ... 3.2. default_deny_file (string) Default file containing deny rules. The file is used by functions without parameters. If you don't specify full pathname then the directory in which the main config file is located will be used. Default value is “permissions.deny”. Example 1.2. Set default_deny_file parameter ... modparam("permissions", "default_deny_file", "/etc/permissions.deny") ... 3.3. check_all_branches (integer) If set then allow_routing functions will check Request-URI of all branches (default). If disabled then only Request-URI of the first branch will be checked. Warning Do not disable this parameter unless you really know what you are doing. Default value is 1. Example 1.3. Set check_all_branches parameter ... modparam("permissions", "check_all_branches", 0) ... 3.4. allow_suffix (string) Suffix to be appended to basename to create filename of the allow file when version with one parameter of either allow_routing or allow_register is used. Note Including leading dot. Default value is “.allow”. Example 1.4. Set allow_suffix parameter ... modparam("permissions", "allow_suffix", ".allow") ... 3.5. deny_suffix (string) Suffix to be appended to basename to create filename of the deny file when version with one parameter of either allow_routing or allow_register is used. Note Including leading dot. Default value is “.deny”. Example 1.5. Set deny_suffix parameter ... modparam("permissions", "deny_suffix", ".deny") ... 3.6. db_url (string) This is URL of the database to be used to store rules used by allow_trusted function. Default value is “NULL”. Example 1.6. Set db_url parameter ... modparam("permissions", "db_url", "dbdriver://username:password@dbhost/dbname") ... 3.7. address_table (string) Name of database table containing IP subnet information used by allow_address and allow_source_address functions. Default value is “address”. Example 1.7. Set address_table parameter ... modparam("permissions", "address_table", "addr") ... 3.8. grp_col (string) Name of address table column containing group identifier of the address. Default value is “grp”. Example 1.8. Set grp_col parameter ... modparam("permissions", "grp_col", "group_id") ... 3.9. ip_addr_col (string) Name of address table column containing IP address part of the address. Default value is “ip_addr”. Example 1.9. Set ip_addr_col parameter ... modparam("permissions", "ip_addr_col", "ip_address") ... 3.10. mask_col (string) Name of address table column containing network mask of the address. Possible values are 0-32. Default value is “mask”. Example 1.10. Set mask_col parameter ... modparam("permissions", "mask_col", "subnet_length") ... 3.11. port_col (string) Name of address table column containing port part of the address. Default value is “port”. Example 1.11. Set port_col parameter ... modparam("permissions", "port_col", "prt") ... 3.12. db_mode (integer) Database mode. 0 means non-caching, 1 means caching. Valid only for allow_trusted function. Default value is 0 (non-caching). Example 1.12. Set db_mode parameter ... modparam("permissions", "db_mode", 1) ... 3.13. trusted_table (string) Name of database table containing matching rules used by allow_trusted function. Default value is “trusted”. Example 1.13. Set trusted_table parameter ... modparam("permissions", "trusted_table", "pbx") ... 3.14. source_col (string) Name of trusted table column containing source IP address that is matched against source IP address of received request. Default value is “src_ip”. Example 1.14. Set source_col parameter ... modparam("permissions", "source_col", "source_ip_address") ... 3.15. proto_col (string) Name of trusted table column containing transport protocol that is matched against transport protocol of received request. Possible values that can be stored in proto_col are “any”, “udp”, “tcp”, “tls”, “sctp”, and “none”. Value “any” matches always and value “none” never. Default value is “proto”. Example 1.15. Set proto_col parameter ... modparam("permissions", "proto_col", "transport") ... 3.16. from_col (string) Name of trusted table column containing regular expression that is matched against From URI. Default value is “from_pattern”. Example 1.16. Set from_col parameter ... modparam("permissions", "from_col", "regexp") ... 3.17. tag_col (string) Name of address or trusted table column containing a string that is added as value to peer_tag AVP if peer_tag AVP has been defined and if the address or peer matches. Default value is “tag”. Example 1.17. Set tag_col parameter ... modparam("permissions", "tag_col", "peer_tag") ... 3.18. peer_tag_avp (AVP string) If defined, the AVP will be set as side effect of allow_trusted() call to not NULL tag column value of the matching peer. Default value is “undefined”. Example 1.18. Set peer_tag_avp parameter ... modparam("permissions", "peer_tag_avp", "$avp(i:707)") ... 3.19. peer_tag_mode (integer) Tag mode for allow_trusted(). 0 sets only the tag of the first match. 1 adds the tags of all matches to the avp. In addition the return value of allow_trusted() is the number of matches. Default value is “0”. Example 1.19. Set peer_tag_mode parameter ... modparam("permissions", "peer_tag_mode", "1") ... 4. Functions 4.1. allow_routing() 4.2. allow_routing(basename) 4.3. allow_routing(allow_file,deny_file) 4.4. allow_register(basename) 4.5. allow_register(allow_file, deny_file) 4.6. allow_uri(basename, pvar) 4.7. allow_address(group_id, ip_addr_pvar, port_pvar) 4.8. allow_source_address([group_id]) 4.9. allow_source_address_group() 4.10. allow_trusted([src_ip_pvar, proto_pvar]) 4.1. allow_routing() Returns true if all pairs constructed as described in Section 1.1, “Call Routing” have appropriate permissions according to the configuration files. This function uses default configuration files specified in default_allow_file and default_deny_file. This function can be used from REQUEST_ROUTE, FAILURE_ROUTE. Example 1.20. allow_routing usage ... if (allow_routing()) { t_relay(); }; ... 4.2. allow_routing(basename) Returns true if all pairs constructed as described in Section 1.1, “Call Routing” have appropriate permissions according to the configuration files given as parameters. Meaning of the parameters is as follows: * basename - Basename from which allow and deny filenames will be created by appending contents of allow_suffix and deny_suffix parameters. If the parameter doesn't contain full pathname then the function expects the file to be located in the same directory as the main configuration file of the server. This function can be used from REQUEST_ROUTE, FAILURE_ROUTE. Example 1.21. allow_routing(basename) usage ... if (allow_routing("basename")) { t_relay(); }; ... 4.3. allow_routing(allow_file,deny_file) Returns true if all pairs constructed as described in Section 1.1, “Call Routing” have appropriate permissions according to the configuration files given as parameters. Meaning of the parameters is as follows: * allow_file - File containing allow rules. If the parameter doesn't contain full pathname then the function expects the file to be located in the same directory as the main configuration file of the server. * deny_file - File containing deny rules. If the parameter doesn't contain full pathname then the function expects the file to be located in the same directory as the main configuration file of the server. This function can be used from REQUEST_ROUTE, FAILURE_ROUTE. Example 1.22. allow_routing(allow_file, deny_file) usage ... if (allow_routing("rules.allow", "rules.deny")) { t_relay(); }; ... 4.4. allow_register(basename) The function returns true if all pairs constructed as described in Section 1.2, “Registration Permissions” have appropriate permissions according to the configuration files given as parameters. Meaning of the parameters is as follows: * basename - Basename from which allow and deny filenames will be created by appending contents of allow_suffix and deny_suffix parameters. If the parameter doesn't contain full pathname then the function expects the file to be located in the same directory as the main configuration file of the server. This function can be used from REQUEST_ROUTE, FAILURE_ROUTE. Example 1.23. allow_register(basename) usage ... if (method=="REGISTER") { if (allow_register("register")) { save("location"); exit; } else { sl_send_reply("403", "Forbidden"); }; }; ... 4.5. allow_register(allow_file, deny_file) The function returns true if all pairs constructed as described in Section 1.2, “Registration Permissions” have appropriate permissions according to the configuration files given as parameters. Meaning of the parameters is as follows: * allow_file - File containing allow rules. If the parameter doesn't contain full pathname then the function expects the file to be located in the same directory as the main configuration file of the server. * deny_file - File containing deny rules. If the parameter doesn't contain full pathname then the function expects the file to be located in the same directory as the main configuration file of the server. This function can be used from REQUEST_ROUTE, FAILURE_ROUTE. Example 1.24. allow_register(allow_file, deny_file) usage ... if (method=="REGISTER") { if (allow_register("register.allow", "register.deny")) { save("location"); exit; } else { sl_send_reply("403", "Forbidden"); }; }; ... 4.6. allow_uri(basename, pvar) Returns true if the pair constructed as described in Section 1.3, “URI Permissions” have appropriate permissions according to the configuration files specified by the parameter. Meaning of the parameter is as follows: * basename - Basename from which allow and deny filenames will be created by appending contents of allow_suffix and deny_suffix parameters. If the parameter doesn't contain full pathname then the function expects the file to be located in the same directory as the main configuration file of the server. * pvar - Any pseudo-variable defined in Kamailio. This function can be used from REQUEST_ROUTE, FAILURE_ROUTE. Example 1.25. allow_uri(basename, pvar) usage ... if (allow_uri("basename", "$rt")) { // Check Refer-To URI t_relay(); }; if (allow_uri("basename", "$avp(i:705)") { // Check URI stored in $avp(i:705) t_relay(); }; ... 4.7. allow_address(group_id, ip_addr_pvar, port_pvar) Returns true if IP address and port given as values of pvar arguments belonging to a group given as group_id argument matches an IP subnet found in cached address table. Cached address table entry containing port value 0 matches any port. group_id argument can be an integer string or a pseudo variable. This function can be used from REQUEST_ROUTE, FAILURE_ROUTE. Example 1.26. allow_address() usage ... // Check if source address/port is in group 1 if (!allow_address("1", "$si", "$sp")) { sl_send_reply("403", "Forbidden"); }; // Check IP address/port stored in AVPs i:704/i:705 is in group 2 if (!allow_address("2", "$avp(i:704)", "$avp(i:705)") { sl_send_reply("403", "Forbidden"); }; ... 4.8. allow_source_address([group_id]) Equal to allow_address(group_id, "$si", "$sp"). If 'group_id' is missing, the function is equal to allow_address("1", "$si", "$sp"). This function can be used from REQUEST_ROUTE, FAILURE_ROUTE. Example 1.27. allow_source_address(group_id) usage ... // Check source address/port of request if (!allow_source_address("1")) { sl_send_reply("403", "Forbidden"); }; ... 4.9. allow_source_address_group() Checks if source address/port is found in cached address or subnet table in any group. If yes, returns that group. If not returns -1. Port value 0 in cached address and group table matches any port. This function can be used from REQUEST_ROUTE, FAILURE_ROUTE. Example 1.28. allow_source_address_group() usage ... $var(group) = allow_source_address_group(); if ($var(group) != -1) { # do something with $var(group) }; ... 4.10. allow_trusted([src_ip_pvar, proto_pvar]) Checks based either on request's source address and transport protocol or source address and transport protocol given in pvar arguments, and From URI of request if request can be trusted without authentication. Returns 1 if a match is found as described in Section 1.5, “Trusted Requests” and -1 otherwise. If a match is found and peer_tag_avp has been defined, adds a non-NULL tag column value of the matching peer to AVP peer_tag_avp. Source address and transport protocol given in pvar arguments must be in string format. Valid transport protocol values are (ignoring case) "any", "udp, "tcp", "tls", and "sctp". This function can be used from REQUEST_ROUTE, FAILURE_ROUTE. Example 1.29. allow_trusted() usage ... if (allow_trusted()) { t_relay(); }; ... if (allow_trusted("$si", "$proto")) { t_relay(); }; ... 5. MI Commands 5.1. address_reload 5.2. address_dump 5.3. subnet_dump 5.4. trusted_reload 5.5. trusted_dump 5.6. allow_uri 5.1. address_reload Causes permissions module to re-read the contents of address database table into cache memory. In cache memory the entries are for performance reasons stored in two different tables: address table and subnet table depending on the value of the mask field (32 or smaller). Parameters: none 5.2. address_dump Causes permissions module to dump contents of cache memory address table. Parameters: none 5.3. subnet_dump Causes permissions module to dump contents of cache memory subnet table. Parameters: none 5.4. trusted_reload Causes permissions module to re-read the contents of trusted table into cache memory. Parameters: none 5.5. trusted_dump Causes permissions module to dump contents of trusted table from cache memory. Parameters: none 5.6. allow_uri Tests if (URI, Contact) pair is allowed according to allow/deny files. The files must already have been loaded by Kamailio. Parameters: * basename - Basename from which allow and deny filenames will be created by appending contents of allow_suffix and deny_suffix parameters. * URI - URI to be tested * Contact - Contact to be tested