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Data Structures
ip-utils.h File Reference

IP address related utility functions (headers) More...

#include <ifaddrs.h>
#include <netinet/in.h>
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Data Structures

struct  janus_network_query_config
 Internal object representation of a network device query (configuration). More...
 
struct  janus_network_address
 Structure to hold network addresses in a tagged union which should be IPv4 and IPv6 compatible. Use the family member (either AF_INET or AF_INET6) to determine which type of address is contained. More...
 
struct  janus_network_address_string_buffer
 Structure to hold human readable forms of network addresses in a tagged union which should be IPv4 and IPv6 compatible. Use the family member (either AF_INET or AF_INET6) to determine which type of representation is contained. More...
 

Janus helper methods to match names and addresses with network interfaces/devices.

enum  janus_network_query_options {
  janus_network_query_options_none = 0, janus_network_query_options_name = 1, janus_network_query_options_ipv4 = 2, janus_network_query_options_ipv6 = 4,
  janus_network_query_options_any_ip = 6, janus_network_query_options_any = 7
}
 
typedef enum janus_network_query_options janus_network_query_options
 
typedef struct janus_network_query_config janus_network_query_config
 Internal object representation of a network device query (configuration). More...
 
typedef struct janus_network_address janus_network_address
 Structure to hold network addresses in a tagged union which should be IPv4 and IPv6 compatible. Use the family member (either AF_INET or AF_INET6) to determine which type of address is contained. More...
 
typedef struct janus_network_address_string_buffer janus_network_address_string_buffer
 Structure to hold human readable forms of network addresses in a tagged union which should be IPv4 and IPv6 compatible. Use the family member (either AF_INET or AF_INET6) to determine which type of representation is contained. More...
 
int janus_network_prepare_device_query (const char *user_value, const janus_network_query_options query_mode, janus_network_query_config *query)
 Initialise a network device query. More...
 
int janus_network_prepare_device_query_default (const char *user_value, janus_network_query_config *query)
 Initialise a network device query with default query options. This function will Initialise the query to accept any supported match type. More...
 
const struct ifaddrs * janus_network_query_devices (const struct ifaddrs *ifas, const janus_network_query_config *query)
 Look up network devices matching the given query. The first matching device is returned, so to find all matching devices simply pass the ifa_next of the returned device in a subsequent call to this function to find more matches. More...
 
int janus_network_get_devices_ipv4 (const struct ifaddrs *ifa, const janus_network_query_config *query, struct in_addr *result)
 Copies the IPv4 address from a network inteface description to the given result structure. More...
 
int janus_network_get_devices_ipv6 (const struct ifaddrs *ifa, const janus_network_query_config *query, struct in6_addr *result)
 Copies the IPv6 address from a network inteface description to the given result structure. More...
 
int janus_network_get_device_address (const struct ifaddrs *ifa, janus_network_address *result)
 Copies the IP address from a network interface description to the given result structure. More...
 
void janus_network_address_nullify (janus_network_address *a)
 Set the given network address to a null/nil value. More...
 
int janus_network_address_is_null (const janus_network_address *a)
 Test if a given network address is null-valued. More...
 
int janus_network_address_from_sockaddr (struct sockaddr *s, janus_network_address *a)
 Convert a struct sockaddr to a janus_network_address. More...
 
int janus_network_address_to_string_buffer (const janus_network_address *a, janus_network_address_string_buffer *buf)
 Convert the given network address to a form which can be used to extract a human readable network address from. More...
 
void janus_network_address_string_buffer_nullify (janus_network_address_string_buffer *b)
 Set the given network address string buffer to a null/nil value. More...
 
int janus_network_address_string_buffer_is_null (const janus_network_address_string_buffer *b)
 Test if a given network address string buffer is null-valued. More...
 
const char * janus_network_address_string_from_buffer (const janus_network_address_string_buffer *b)
 Extract the human readable representation of a network address from a given buffer. More...
 
int janus_network_string_is_valid_address (janus_network_query_options addr_type, const char *user_value)
 Test if a given IP address string is a valid address of the specified type. More...
 
int janus_network_string_to_address (janus_network_query_options addr_type, const char *user_value, janus_network_address *result)
 Convert an IP address string to a janus_network_address instance. More...
 
int janus_network_lookup_interface (const struct ifaddrs *ifas, const char *iface, janus_network_address *result)
 Convert an interface name or IP address to a janus_network_address instance. More...
 
int janus_network_detect_local_ip (janus_network_query_options addr_type, janus_network_address *result)
 Helper method to find a valid local IP address, that is an address that can be used to communicate. More...
 
char * janus_network_detect_local_ip_as_string (janus_network_query_options addr_type)
 Wrapper to janus_network_detect_local_ip that returns a string instead. More...
 

Detailed Description

IP address related utility functions (headers)

Author
Johan Ouwerkerk jm.ou.nosp@m.werk.nosp@m.erk@g.nosp@m.mail.nosp@m..com

Parsing IPv4/IPv6 addresses is robust against malformed input.

See also
man 3 getifaddrs
man 3 inet_pton

Core

Typedef Documentation

◆ janus_network_address

Structure to hold network addresses in a tagged union which should be IPv4 and IPv6 compatible. Use the family member (either AF_INET or AF_INET6) to determine which type of address is contained.

See also
man 7 ip
man 7 ipv6
janus_network_get_device_address

◆ janus_network_address_string_buffer

Structure to hold human readable forms of network addresses in a tagged union which should be IPv4 and IPv6 compatible. Use the family member (either AF_INET or AF_INET6) to determine which type of representation is contained.

See also
man 7 ip
man 7 ipv6
janus_network_address_to_string_buffer

◆ janus_network_query_config

Internal object representation of a network device query (configuration).

◆ janus_network_query_options

Enumeration Type Documentation

◆ janus_network_query_options

Enumerator
janus_network_query_options_none 
janus_network_query_options_name 
janus_network_query_options_ipv4 
janus_network_query_options_ipv6 
janus_network_query_options_any_ip 
janus_network_query_options_any 

Function Documentation

◆ janus_network_address_from_sockaddr()

int janus_network_address_from_sockaddr ( struct sockaddr *  s,
janus_network_address a 
)

Convert a struct sockaddr to a janus_network_address.

Parameters
sThe struct sockaddr to convert
aThe address to write to
Returns
0 on success, or -EINVAL otherwise.

◆ janus_network_address_is_null()

int janus_network_address_is_null ( const janus_network_address a)

Test if a given network address is null-valued.

Parameters
aThe address to check
Returns
A positive integer if the given address is null-valued, 0 otherwise.
See also
janus_network_address_nullify

◆ janus_network_address_nullify()

void janus_network_address_nullify ( janus_network_address a)

Set the given network address to a null/nil value.

Parameters
aThe address to nullify. Nothing is done if the pointer is NULL itself.
See also
janus_network_address_is_null

◆ janus_network_address_string_buffer_is_null()

int janus_network_address_string_buffer_is_null ( const janus_network_address_string_buffer b)

Test if a given network address string buffer is null-valued.

Parameters
bThe buffer to check
Returns
A positive integer if the given buffer is null-valued, 0 otherwise.
See also
janus_network_address_string_buffer_nullify

◆ janus_network_address_string_buffer_nullify()

void janus_network_address_string_buffer_nullify ( janus_network_address_string_buffer b)

Set the given network address string buffer to a null/nil value.

Parameters
bThe address to nullify. Nothing is done if the pointer is NULL itself.
See also
janus_network_address_string_buffer_is_null

◆ janus_network_address_string_from_buffer()

const char* janus_network_address_string_from_buffer ( const janus_network_address_string_buffer b)

Extract the human readable representation of a network address from a given buffer.

Parameters
bThe buffer containing the given network
Returns
A pointer to the human readable representation of the network address inside the given buffer, or NULL if the buffer is invalid or NULL.
See also
janus_network_address_to_string_buffer

◆ janus_network_address_to_string_buffer()

int janus_network_address_to_string_buffer ( const janus_network_address a,
janus_network_address_string_buffer buf 
)

Convert the given network address to a form which can be used to extract a human readable network address from.

Parameters
aThe address to convert
bufA buffer to contain the human readable form.
Returns
0 on success, or -EINVAL if any argument is NULL.
See also
janus_network_address
janus_network_address_string_buffer
janus_network_address_string_from_buffer
man 3 inet_ntop

◆ janus_network_detect_local_ip()

int janus_network_detect_local_ip ( janus_network_query_options  addr_type,
janus_network_address result 
)

Helper method to find a valid local IP address, that is an address that can be used to communicate.

Parameters
addr_typeThe type of address you're interested in (janus_network_query_options_ipv4, janus_network_query_options_ipv6 or janus_network_query_options_any_ip)
resultPointer to a valid janus_network_address instance that will contain the result
Returns
0 in case of success, -EINVAL otherwise otherwise

◆ janus_network_detect_local_ip_as_string()

char* janus_network_detect_local_ip_as_string ( janus_network_query_options  addr_type)

Wrapper to janus_network_detect_local_ip that returns a string instead.

Note
The string is allocated with g_strdup and so needs to be freed by the caller
Parameters
addr_typeThe type of address you're interested in (janus_network_query_options_ipv4, janus_network_query_options_ipv6 or janus_network_query_options_any_ip)
Returns
0 in case of success, -EINVAL otherwise otherwise

◆ janus_network_get_device_address()

int janus_network_get_device_address ( const struct ifaddrs *  ifa,
janus_network_address result 
)

Copies the IP address from a network interface description to the given result structure.

Returns
0 on success, or -EINVAL if any argument is NULL or the given network interface does not correspond to an IP address.
See also
janus_network_address

◆ janus_network_get_devices_ipv4()

int janus_network_get_devices_ipv4 ( const struct ifaddrs *  ifa,
const janus_network_query_config query,
struct in_addr *  result 
)

Copies the IPv4 address from a network inteface description to the given result structure.

Parameters
ifaThe network interface description to grab the IPv4 address from. It should be obtained with janus_network_query_devices().
queryA description of the criteria to look for when determining whether or not a network interface is a match
resultPointer to a structure to populate with the IPv4 address of the given network interface
Returns
0 on success, -EINVAL if any argument is NULL or the network interface description or the network device query do not correspond to an IPv4 configuration.
See also
man 7 ip
janus_network_query_devices

◆ janus_network_get_devices_ipv6()

int janus_network_get_devices_ipv6 ( const struct ifaddrs *  ifa,
const janus_network_query_config query,
struct in6_addr *  result 
)

Copies the IPv6 address from a network inteface description to the given result structure.

Parameters
ifaThe network interface description to grab the IPv6 address from. It should be obtained with janus_network_query_devices().
queryA description of the criteria to look for when determining whether or not a network interface is a match
resultPointer to a structure to populate with the IPv6 address of the given network interface
Returns
0 on success, -EINVAL if any argument is NULL or the network interface description or the network device query do not correspond to an IPv6 configuration.
See also
man 7 ipv6
janus_network_query_devices

◆ janus_network_lookup_interface()

int janus_network_lookup_interface ( const struct ifaddrs *  ifas,
const char *  iface,
janus_network_address result 
)

Convert an interface name or IP address to a janus_network_address instance.

Parameters
ifasThe list of interfaces to look into (e.g., as returned from getifaddrs)
ifaceThe interface name or IP address to look for
resultPointer to a valid janus_network_address instance that will contain the result
Returns
0 in case of success, -EINVAL otherwise otherwise

◆ janus_network_prepare_device_query()

int janus_network_prepare_device_query ( const char *  user_value,
const janus_network_query_options  query_mode,
janus_network_query_config query 
)

Initialise a network device query.

Parameters
user_valueThe user-supplied string which is supposed to describe either the device name or its IP address.
query_mode(A mask of) Options describing the supported types of matches which should be accepted when performing a look up with this query. This can be used to restrict the query to 'by device name' or 'IPv4 only' type searches.
queryThe query object to configure.
Returns
0 on success or -EINVAL if any of the arguments are NULL or the given value to look for does not correspond to a valid IPv4/IPv6 address and matching by name is disabled.
See also
janus_network_query_options

◆ janus_network_prepare_device_query_default()

int janus_network_prepare_device_query_default ( const char *  user_value,
janus_network_query_config query 
)

Initialise a network device query with default query options. This function will Initialise the query to accept any supported match type.

Parameters
user_valueThe user-supplied string which is supposed to describe either the device name or its IP address.
queryThe query object to configure.
Returns
0 on success, or -EINVAL if any of the arguments are NULL
See also
janus_network_prepare_device_query

◆ janus_network_query_devices()

const struct ifaddrs* janus_network_query_devices ( const struct ifaddrs *  ifas,
const janus_network_query_config query 
)

Look up network devices matching the given query. The first matching device is returned, so to find all matching devices simply pass the ifa_next of the returned device in a subsequent call to this function to find more matches.

Parameters
ifasThe first node of the list of network interfaces to search through. This should be obtained (indirectly) from getifaddrs().
queryA description of the criteria to look for when determining whether or not a network interface is a match.
Returns
a pointer to a node describing the matching network interface or NULL if no (further) match was found.
See also
man 3 getifaddrs

◆ janus_network_string_is_valid_address()

int janus_network_string_is_valid_address ( janus_network_query_options  addr_type,
const char *  user_value 
)

Test if a given IP address string is a valid address of the specified type.

Parameters
addr_typeThe type of address you're interested in (janus_network_query_options_ipv4, janus_network_query_options_ipv6 or janus_network_query_options_any_ip)
user_valueThe IP address string to check
Returns
A positive integer if the given string is a valid address, 0 otherwise.

◆ janus_network_string_to_address()

int janus_network_string_to_address ( janus_network_query_options  addr_type,
const char *  user_value,
janus_network_address result 
)

Convert an IP address string to a janus_network_address instance.

Parameters
addr_typeThe type of address you're interested in (janus_network_query_options_ipv4, janus_network_query_options_ipv6 or janus_network_query_options_any_ip)
user_valueThe IP address string to check
resultPointer to a valid janus_network_address instance that will contain the result
Returns
0 in case of success, -EINVAL otherwise otherwise