Packet Location Aliasing

Packet Location Aliasing. More...

Functions
int	rtnl_pktloc_lookup (const char *name, struct rtnl_pktloc **result)
	Lookup packet location alias. More...
struct rtnl_pktloc *	rtnl_pktloc_alloc (void)
	Allocate packet location object. More...
void	rtnl_pktloc_put (struct rtnl_pktloc *loc)
	Return reference of a packet location. More...
int	rtnl_pktloc_add (struct rtnl_pktloc *loc)
	Add a packet location to the hash table. More...
void	rtnl_pktloc_foreach (void(*cb)(struct rtnl_pktloc *, void *), void *arg)

Detailed Description

Packet Location Aliasing.

The packet location aliasing interface eases the use of offset definitions inside packets by allowing them to be referenced by name. Known positions of protocol fields are stored in a configuration file and associated with a name for later reference. The configuration file is distributed with the library and provides a well defined set of definitions for most common protocol fields.

Examples

Example 1.1 Looking up a packet location

struct rtnl_pktloc *loc;
 
rtnl_pktloc_lookup("ip.src", &loc);

Function Documentation

rtnl_pktloc_lookup()

int rtnl_pktloc_lookup	(	const char *	name,
		struct rtnl_pktloc **	result
	)

Lookup packet location alias.

Parameters

name	Name of packet location.
result	Result pointer

Tries to find a matching packet location alias for the supplied packet location name.

The file containing the packet location definitions is automatically re-read if its modification time has changed since the last call.

The returned packet location has to be returned after use by calling rtnl_pktloc_put() in order to allow freeing its memory after the last user has abandoned it.

Returns

0 on success or a negative error code.

Return values

NLE_PKTLOC_FILE	Unable to open packet location file.
NLE_OBJ_NOTFOUND	No matching packet location alias found.

Definition at line 167 of file pktloc.c.

rtnl_pktloc_alloc()

struct rtnl_pktloc * rtnl_pktloc_alloc

(

void

)

Allocate packet location object.

Definition at line 180 of file pktloc.c.

rtnl_pktloc_put()

void rtnl_pktloc_put

(

struct rtnl_pktloc *

loc

)

Return reference of a packet location.

Parameters

loc	packet location object.

Definition at line 197 of file pktloc.c.

Referenced by rtnl_pktloc_add().

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rtnl_pktloc_add()

int rtnl_pktloc_add

(

struct rtnl_pktloc *

loc

)

Add a packet location to the hash table.

Parameters

loc	packet location object

Returns

0 on success or a negative error code.

Definition at line 213 of file pktloc.c.

References rtnl_pktloc_put().

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rtnl_pktloc_foreach()

void rtnl_pktloc_foreach	(	void(*)(struct rtnl_pktloc *, void *)	cb,
		void *	arg
	)

Definition at line 232 of file pktloc.c.