/* * Asterisk -- An open source telephony toolkit. * * Copyright (C) 1999 - 2006, Digium, Inc. * * Mark Spencer * * See http://www.asterisk.org for more information about * the Asterisk project. Please do not directly contact * any of the maintainers of this project for assistance; * the project provides a web site, mailing lists and IRC * channels for your use. * * This program is free software, distributed under the terms of * the GNU General Public License Version 2. See the LICENSE file * at the top of the source tree. */ /*! \file * \brief Access Control of various sorts */ #ifndef _ASTERISK_ACL_H #define _ASTERISK_ACL_H #if defined(__cplusplus) || defined(c_plusplus) extern "C" { #endif #include #include "asterisk/io.h" #define AST_SENSE_DENY 0 #define AST_SENSE_ALLOW 1 /* Host based access control */ struct ast_ha { /* Host access rule */ struct in_addr netaddr; struct in_addr netmask; int sense; struct ast_ha *next; }; /*! * \brief Free a list of HAs * * \details * Given the head of a list of HAs, it and all appended * HAs are freed * * \param ha The head of the list of HAs to free * \retval void */ void ast_free_ha(struct ast_ha *ha); /*! * \brief Copy the contents of one HA to another * * \details * This copies the internals of the 'from' HA to the 'to' * HA. It is important that the 'to' HA has been allocated * prior to calling this function * * \param from Source HA to copy * \param to Destination HA to copy to * \retval void */ void ast_copy_ha(const struct ast_ha *from, struct ast_ha *to); /*! * \brief Add a new rule to a list of HAs * * \details * This adds the new host access rule to the end of the list * whose head is specified by the path parameter. Rules are * evaluated in a way such that if multiple rules apply to * a single IP address/subnet mask, then the rule latest * in the list will be used. * * \param sense Either "permit" or "deny" (Actually any 'p' word will result * in permission, and any other word will result in denial) * \param stuff The IP address and subnet mask, separated with a '/'. The subnet * mask can either be in dotted-decimal format or in CIDR notation (i.e. 0-32). * \param path The head of the HA list to which we wish to append our new rule. If * NULL is passed, then the new rule will become the head of the list * \return The head of the HA list */ struct ast_ha *ast_append_ha(char *sense, const char *stuff, struct ast_ha *path); /*! * \brief Apply a set of rules to a given IP address * * \details * The list of host access rules is traversed, beginning with the * input rule. If the IP address given matches a rule, the "sense" * of that rule is used as the return value. Note that if an IP * address matches multiple rules that the last one matched will be * the one whose sense will be returned. * * \param ha The head of the list of host access rules to follow * \param sin A sockaddr_in whose address is considered when matching rules * \retval AST_SENSE_ALLOW The IP address passes our ACL * \retval AST_SENSE_DENY The IP address fails our ACL */ int ast_apply_ha(struct ast_ha *ha, struct sockaddr_in *sin); /*! * \brief Get the IP address given a hostname * * \details * Similar in nature to ast_gethostbyname, except that instead * of getting an entire hostent structure, you instead are given * only the IP address inserted into a sockaddr_in structure. * * \param[out] sin The IP address is written into sin->sin_addr * \param value The hostname to look up * \retval 0 Success * \retval -1 Failure */ int ast_get_ip(struct sockaddr_in *sin, const char *value); /*! * \brief Get the IP address given a hostname and optional service * * \details * If the service parameter is non-NULL, then an SRV lookup will be made by * prepending the service to the value parameter, separated by a '.' * For example, if value is "example.com" and service is "_sip._udp" then * an SRV lookup will be done for "_sip._udp.example.com". If service is NULL, * then this function acts exactly like a call to ast_get_ip. * * \param[out] sin The IP address is written into sin->sin_addr * \param value The hostname to look up * \param service A specific service provided by the host. A NULL service results * in an A-record lookup instead of an SRV lookup * \retval 0 Success * \retval -1 Failure */ int ast_get_ip_or_srv(struct sockaddr_in *sin, const char *value, const char *service); /*! * \brief Get our local IP address when contacting a remote host * * \details * This function will attempt to connect(2) to them over UDP using a source * port of 5060. If the connect(2) call is successful, then we inspect the * sockaddr_in output parameter of connect(2) to determine the IP address * used to connect to them. This IP address is then copied into us. * * \param them The IP address to which we wish to attempt to connect * \param[out] us The source IP address used to connect to them * \retval -1 Failure * \retval 0 Success */ int ast_ouraddrfor(struct in_addr *them, struct in_addr *us); /*! * \brief Find an IP address associated with a specific interface * * \details * Given an interface such as "eth0" we find the primary IP address * associated with it using the SIOCGIFADDR ioctl. If the ioctl call * should fail, we populate address with 0s. * * \note * This function is not actually used anywhere * * \param iface The interface name whose IP address we wish to find * \param[out] address The interface's IP address is placed into this param * \retval -1 Failure. address is filled with 0s * \retval 0 Success */ int ast_lookup_iface(char *iface, struct in_addr *address); /*! * \brief Duplicate the contents of a list of host access rules * * \details * A deep copy of all ast_has in the list is made. The returned * value is allocated on the heap and must be freed independently * of the input parameter when finished. * * \note * This function is not actually used anywhere. * * \param original The ast_ha to copy * \retval The head of the list of duplicated ast_has */ struct ast_ha *ast_duplicate_ha_list(struct ast_ha *original); /*! * \brief Find our IP address * * \details * This function goes through many iterations in an attempt to find * our IP address. If any step along the way should fail, we move to the * next item in the list. Here are the steps taken: * - If bindaddr has a non-zero IP address, that is copied into ourip * - We use a combination of gethostname and ast_gethostbyname to find our * IP address. * - We use ast_ouraddrfor with 198.41.0.4 as the destination IP address * - We try some platform-specific socket operations to find the IP address * * \param[out] ourip Our IP address is written here when it is found * \param bindaddr A hint used for finding our IP. See the steps above for * more details * \retval 0 Success * \retval -1 Failure */ int ast_find_ourip(struct in_addr *ourip, struct sockaddr_in bindaddr); /*! * \brief Convert a string to the appropriate TOS value * * \param value The TOS string to convert * \param[out] The integer representation of that TOS value * \retval -1 Failure * \retval 0 Success */ int ast_str2tos(const char *value, unsigned int *tos); /*! * \brief Convert a TOS value into its string representation * * \param tos The TOS value to look up * \return The string equivalent of the TOS value */ const char *ast_tos2str(unsigned int tos); #if defined(__cplusplus) || defined(c_plusplus) } #endif #endif /* _ASTERISK_ACL_H */