src / core

dmesh.c File Reference

Detailed Description

Download mesh.

Author:: Raphael Manfredi

Date:: 2002-2007

#include "common.h"
#include "gnutella.h"
#include "downloads.h"
#include "uploads.h"
#include "dmesh.h"
#include "huge.h"
#include "http.h"
#include "hostiles.h"
#include "guid.h"
#include "share.h"
#include "fileinfo.h"
#include "settings.h"
#include "hosts.h"
#include "if/gnet_property_priv.h"
#include "lib/atoms.h"
#include "lib/base32.h"
#include "lib/cq.h"
#include "lib/endian.h"
#include "lib/file.h"
#include "lib/getdate.h"
#include "lib/glib-missing.h"
#include "lib/hashlist.h"
#include "lib/header.h"
#include "lib/tm.h"
#include "lib/url.h"
#include "lib/urn.h"
#include "lib/walloc.h"
#include "lib/override.h"

Data Structures

struct dmesh

struct dmesh_entry

struct dmesh_banned

Defines

#define MAX_LIFETIME   86400

1 day

#define MAX_ENTRIES   256

Max amount of entries kept per SHA1.

#define MIN_PFSP_SIZE   524288

512K, min size for PFSP advertising

#define MIN_PFSP_PCT   10

10%, min available data for PFSP

#define MIN_BAD_REPORT   2

Don't ban before that many X-Nalt.

#define BAN_LIFETIME   7200

2 hours

#define DMESH_MAX   MAX_ENTRIES

Typedefs

typedef void(* dmesh_add_cb )(const struct sha1 *sha1, host_addr_t addr, guint16 port, gpointer udata)

typedef void(* header_func_t )(FILE *out)

Functions

void dmesh_retrieve (void)

Retrieve download mesh and add entries that have not expired yet.

void dmesh_ban_retrieve (void)

Retrieve banned mesh and add entries that have not expired yet.

gchar * dmesh_urlinfo_to_string (const dmesh_urlinfo_t *info)

Format the `info' URL and return pointer to static string.

guint urlinfo_hash (gconstpointer key)

Hash a URL info.

gint urlinfo_eq (gconstpointer a, gconstpointer b)

Test equality of two URL infos.

void dmesh_init (void)

Initialize the download mesh.

void dmesh_entry_free (struct dmesh_entry *dme)

Free download mesh entry.

void dmesh_fill_info (dmesh_urlinfo_t *info, const struct sha1 *sha1, const host_addr_t addr, guint16 port, guint idx, const gchar *name)

Fill URL info from externally supplied sha1, addr, port, idx and name.

void dmesh_urlinfo_free (dmesh_urlinfo_t *info)

Free a dmesh_urlinfo_t structure.

void dmesh_ban_remove_entry (struct dmesh_banned *dmb)

Remove entry from banned mesh.

void dmesh_ban_expire (cqueue_t *unused_cq, gpointer obj)

Called from callout queue when it's time to expire the URL ban.

void dmesh_ban_add (const struct sha1 *sha1, dmesh_urlinfo_t *info, time_t stamp)

Add new URL to the banned hash.

void dmesh_ban_remove (const struct sha1 *sha1, host_addr_t addr, guint16 port)

Forcefully remove an entry from the banned mesh.

gboolean dmesh_is_banned (const dmesh_urlinfo_t *info)

Check whether URL is banned from the mesh.

const gchar * dmesh_url_strerror (dmesh_url_error_t errnum)

gboolean dmesh_url_parse (const gchar *url, dmesh_urlinfo_t *info)

Parse URL `url', and fill a structure `info' representing this URL.

dmesh * dm_alloc (const struct sha1 *sha1)

Allocate a new download mesh structure (there is one per SHA1).

void dm_free (struct dmesh *dm)

Free download mesh structure.

void dm_remove_entry (struct dmesh *dm, struct dmesh_entry *dme)

Remove specified entry from mesh bucket and reclaim it.

void dm_remove (struct dmesh *dm, const host_addr_t addr, guint16 port)

Remove the addr:port entry from mesh bucket, if present.

void dm_expire (struct dmesh *dm, glong agemax)

Expire entries older than `agemax' in a given mesh bucket `dm'.

void dmesh_dispose (const struct sha1 *sha1)

Dispose of the entry slot, which must be empty.

gboolean dmesh_remove (const struct sha1 *sha1, const host_addr_t addr, guint16 port, guint idx, const gchar *name)

Remove entry from mesh due to a failed download attempt.

gint dmesh_count (const struct sha1 *sha1)

Get the number of dmesh entries for a given SHA1.

gboolean dmesh_raw_add (const struct sha1 *sha1, const dmesh_urlinfo_t *info, time_t stamp)

Add entry to the download mesh, indexed by the binary `sha1' digest.

gboolean dmesh_add (const struct sha1 *sha1, const host_addr_t addr, guint16 port, guint idx, const gchar *name, time_t stamp)

Same as dmesh_raw_add(), but this is for public consumption.

void dmesh_add_alternate (const struct sha1 *sha1, host_addr_t addr, guint16 port)

Add addr:port as a known alternate location for given sha1.

void dmesh_add_good_alternate (const struct sha1 *sha1, host_addr_t addr, guint16 port)

void dmesh_add_alternates (const struct sha1 *sha1, const gnet_host_vec_t *alt)

Add a set of alternate locations (IP + port) to the mesh.

void dmesh_remove_alternate (const struct sha1 *sha1, host_addr_t addr, guint16 port)

Remove addr:port as a known alternate location for given sha1.

void dmesh_negative_alt (const struct sha1 *sha1, host_addr_t reporter, host_addr_t addr, guint16 port)

Record that addr:port was signalled negatively as an alternate location for given sha1.

void dmesh_good_mark (const struct sha1 *sha1, host_addr_t addr, guint16 port, gboolean good)

Flag dmesh entry for this SHA1, address and port as good or bad.

size_t dmesh_urlinfo (const dmesh_urlinfo_t *info, gchar *buf, size_t len, gboolean *quoting)

Format the URL described by `info' into the provided buffer `buf', which can hold `len' bytes.

size_t dmesh_entry_compact (const struct dmesh_entry *dme, gchar *buf, size_t size)

Format mesh_entry in the provided buffer, as a compact addr:port address.

size_t dmesh_entry_url_stamp (const struct dmesh_entry *dme, gchar *buf, size_t size)

Format dmesh_entry in the provided buffer, as an URL with an appended timestamp in ISO format, GMT time.

const gchar * dmesh_entry_to_string (const struct dmesh_entry *dme)

Format the `dme' mesh entry as "URL timestamp".

gint dmesh_fill_alternate (const struct sha1 *sha1, gnet_host_t *hvec, gint hcnt)

Fill supplied vector `hvec' whose size is `hcnt' with some alternate locations for a given SHA1 key, that can be requested by hash directly.

gint dmesh_alternate_location (const struct sha1 *sha1, gchar *buf, size_t size, const host_addr_t addr, time_t last_sent, const gchar *vendor, fileinfo_t *fi, gboolean request)

Build alternate location header for a given SHA1 key.

gboolean dmesh_collect_sha1 (const gchar *value, struct sha1 *sha1)

Parse the value of the X-Gnutella-Content-URN header in `value', looking for a SHA1.

void dmesh_parse_addr_port_list (const struct sha1 *sha1, const gchar *value, dmesh_add_cb func, gpointer udata)

Parse a list of addr:port, such as typically found in "X-Alt" or "X-Nalt" headers to extract alternate sources.

void dmesh_collect_compact_locations_cback (const struct sha1 *sha1, host_addr_t addr, guint16 port, gpointer unused_udata)

void dmesh_collect_compact_locations (const struct sha1 *sha1, const gchar *value)

Parse the value of the "X-Alt" header to extract alternate sources for a given SHA1 key given in the new compact form.

void dmesh_collect_negative_locations_cback (const struct sha1 *sha1, host_addr_t addr, guint16 port, gpointer udata)

void dmesh_collect_negative_locations (const struct sha1 *sha1, const gchar *value, host_addr_t reporter)

Parse the value of the "X-Nalt" header to extract bad sources for a given SHA1 key, given in the new compact form.

void dmesh_collect_locations (const struct sha1 *sha1, const gchar *value)

Parse value of the "X-Gnutella-Alternate-Location" to extract alternate sources for a given SHA1 key.

gint dmesh_alt_loc_fill (const struct sha1 *sha1, dmesh_urlinfo_t *buf, gint count)

Fill buffer with at most `count' alternative locations for sha1.

void dmesh_check_results_set (gnet_results_set_t *rs)

Parse query hit (result set) for entries whose SHA1 match something we have into the mesh or share, and insert them if needed.

void dmesh_multiple_downloads (const struct sha1 *sha1, filesize_t size, fileinfo_t *fi)

This is called when swarming is first requested to get a list of all the servers with the requested file known by dmesh.

void dmesh_store_kv (gpointer key, gpointer value, gpointer udata)

Store key/value pair in file.

void dmesh_store_hash (const gchar *what, GHashTable *hash, const gchar *file, header_func_t header_cb, GHFunc store_cb)

Store hash table `hash' into `file'.

void dmesh_header_print (FILE *out)

Prints header to dmesh store file.

void dmesh_store (void)

Store download mesh onto file.

void dmesh_ban_store_kv (gpointer key, gpointer value, gpointer udata)

Store key/value pair in file.

void dmesh_ban_header_print (FILE *out)

Prints header to banned mesh store file.

void dmesh_ban_store (void)

Store banned mesh onto file.

gboolean dmesh_free_kv (gpointer key, gpointer value, gpointer unused_udata)

Free key/value pair in download mesh hash.

void dmesh_ban_prepend_list (gpointer key, gpointer value, gpointer user)

Prepend the value to the list, given by reference.

void dmesh_close (void)

Called at servent shutdown time.

Variables

dmesh_url_error_t dmesh_url_errno

Error from dmesh_url_parse().

GHashTable * mesh = NULL

The download mesh records all the known sources for a given SHA1.

const gchar dmesh_file [] = "dmesh"

GHashTable * ban_mesh = NULL

If we get a "bad" URL into the mesh ("bad" = gives 404 or other error when trying to download it), we must remember it for some time and prevent it from re-entering the mesh again within that period to prevent rescheduling for download and a further failure: that would be hammering the poor host, and we're wasting our time and bandwidth.

GHashTable * ban_mesh_by_sha1 = NULL

This table stores the banned entries by SHA1.

const gchar dmesh_ban_file [] = "dmesh_ban"

const gchar *const parse_errstr []

Define Documentation

#define BAN_LIFETIME 7200

2 hours

#define DMESH_MAX MAX_ENTRIES

#define MAX_ENTRIES 256

Max amount of entries kept per SHA1.

#define MAX_LIFETIME 86400

1 day

#define MIN_BAD_REPORT 2

Don't ban before that many X-Nalt.

#define MIN_PFSP_PCT 10

10%, min available data for PFSP

#define MIN_PFSP_SIZE 524288

512K, min size for PFSP advertising

Typedef Documentation

typedef void(* dmesh_add_cb)(const struct sha1 *sha1, host_addr_t addr, guint16 port, gpointer udata)

typedef void(* header_func_t)(FILE *out)

Function Documentation

struct dmesh* dm_alloc ( const struct sha1 * sha1 ) [static]

Allocate a new download mesh structure (there is one per SHA1).

void dm_expire ( struct dmesh * dm,

glong agemax

) [static]

Expire entries older than `agemax' in a given mesh bucket `dm'.

void dm_free ( struct dmesh * dm ) [static]

Free download mesh structure.

void dm_remove ( struct dmesh * dm,

const host_addr_t addr,

guint16 port

) [static]

Remove the addr:port entry from mesh bucket, if present.

void dm_remove_entry ( struct dmesh * dm,

struct dmesh_entry * dme

) [static]

Remove specified entry from mesh bucket and reclaim it.

gboolean dmesh_add ( const struct sha1 * sha1,

const host_addr_t addr,

guint16 port,

guint idx,

const gchar * name,

time_t stamp

)

Same as dmesh_raw_add(), but this is for public consumption.

void dmesh_add_alternate ( const struct sha1 * sha1,

host_addr_t addr,

guint16 port

)

Add addr:port as a known alternate location for given sha1.

void dmesh_add_alternates ( const struct sha1 * sha1,

const gnet_host_vec_t * alt

)

Add a set of alternate locations (IP + port) to the mesh.

void dmesh_add_good_alternate ( const struct sha1 * sha1,

host_addr_t addr,

guint16 port

)

gint dmesh_alt_loc_fill ( const struct sha1 * sha1,

dmesh_urlinfo_t * buf,

gint count

) [static]

Fill buffer with at most `count' alternative locations for sha1.

Returns:
the amount of locations inserted.

gint dmesh_alternate_location ( const struct sha1 * sha1,

gchar * buf,

size_t size,

const host_addr_t addr,

time_t last_sent,

const gchar * vendor,

fileinfo_t * fi,

gboolean request

)

Build alternate location header for a given SHA1 key.
We generate at most `size' bytes of data into `alt'.

Parameters:

`sha1' no brief description.

`buf' no brief description.

'size' no brief description.

`addr' is the host to which those alternate locations are meant: we skip any data pertaining to that host.

`last_sent' is the time at which we sent some previous alternate locations. If there has been no change to the mesh since then, we'll return an empty string. Otherwise we return entries inserted after `last_sent'.

`vendor' is given to determine whether it is apt to read our X-Alt and X-Nalt fields formatted with continuations or not.

`fi' when it is non-NULL, it means we're sharing that file and we're sending alternate locations to remote servers: include ourselves in the list of alternate locations if PFSP-server is enabled.

`request' if it is true, then the mesh entries are generated in an HTTP request; otherwise it's for an HTTP reply.

unless the `vendor' is GTKG, don't use continuation: most servent authors don't bother with a proper HTTP header parsing layer.

Returns:
amount of generated data.

void dmesh_ban_add ( const struct sha1 * sha1,

dmesh_urlinfo_t * info,

time_t stamp

) [static]

Add new URL to the banned hash.
If stamp is 0, the current timestamp is used.

void dmesh_ban_expire ( cqueue_t * unused_cq,

gpointer obj

) [static]

Called from callout queue when it's time to expire the URL ban.

void dmesh_ban_header_print ( FILE * out ) [static]

Prints header to banned mesh store file.

void dmesh_ban_prepend_list ( gpointer key,

gpointer value,

gpointer user

) [static]

Prepend the value to the list, given by reference.

void dmesh_ban_remove ( const struct sha1 * sha1,

host_addr_t addr,

guint16 port

) [static]

Forcefully remove an entry from the banned mesh.

void dmesh_ban_remove_entry ( struct dmesh_banned * dmb ) [static]

Remove entry from banned mesh.

void dmesh_ban_retrieve ( void ) [static]

Retrieve banned mesh and add entries that have not expired yet.
The mesh is normally retrieved from ~/.gtk-gnutella/dmesh_ban.

void dmesh_ban_store ( void )

Store banned mesh onto file.
The banned mesh is normally stored in ~/.gtk-gnutella/dmesh_ban.

void dmesh_ban_store_kv ( gpointer key,

gpointer value,

gpointer udata

) [static]

Store key/value pair in file.

void dmesh_check_results_set ( gnet_results_set_t * rs )

Parse query hit (result set) for entries whose SHA1 match something we have into the mesh or share, and insert them if needed.

void dmesh_close ( void )

Called at servent shutdown time.

void dmesh_collect_compact_locations ( const struct sha1 * sha1,

const gchar * value

)

Parse the value of the "X-Alt" header to extract alternate sources for a given SHA1 key given in the new compact form.

void dmesh_collect_compact_locations_cback ( const struct sha1 * sha1,

host_addr_t addr,

guint16 port,

gpointer unused_udata

) [static]

void dmesh_collect_locations ( const struct sha1 * sha1,

const gchar * value

)

Parse value of the "X-Gnutella-Alternate-Location" to extract alternate sources for a given SHA1 key.

void dmesh_collect_negative_locations ( const struct sha1 * sha1,

const gchar * value,

host_addr_t reporter

)

Parse the value of the "X-Nalt" header to extract bad sources for a given SHA1 key, given in the new compact form.

Parameters:

reporter the address of the host supplying the X-Nalt header

void dmesh_collect_negative_locations_cback ( const struct sha1 * sha1,

host_addr_t addr,

guint16 port,

gpointer udata

) [static]

gboolean dmesh_collect_sha1 ( const gchar * value,

struct sha1 * sha1

)

Parse the value of the X-Gnutella-Content-URN header in `value', looking for a SHA1.
When found, the SHA1 is extracted and placed into the given `digest' buffer.

Returns:
whether we successfully extracted the SHA1.

gint dmesh_count ( const struct sha1 * sha1 )

Get the number of dmesh entries for a given SHA1.

Returns:
the number of dmesh entries

void dmesh_dispose ( const struct sha1 * sha1 ) [static]

Dispose of the entry slot, which must be empty.

size_t dmesh_entry_compact ( const struct dmesh_entry * dme,

gchar * buf,

size_t size

) [static]

Format mesh_entry in the provided buffer, as a compact addr:port address.
The port is even omitted if it is the standard Gnutella one.

Returns:
length of formatted entry, -1 if the address would be larger than the buffer, or if no compact form can be derived for this entry (not an URN_INDEX kind).

void dmesh_entry_free ( struct dmesh_entry * dme ) [static]

Free download mesh entry.

const gchar* dmesh_entry_to_string ( const struct dmesh_entry * dme ) [static]

Format the `dme' mesh entry as "URL timestamp".

Returns:
pointer to static string.

size_t dmesh_entry_url_stamp ( const struct dmesh_entry * dme,

gchar * buf,

size_t size

) [static]

Format dmesh_entry in the provided buffer, as an URL with an appended timestamp in ISO format, GMT time.

Returns:
length of formatted entry, -1 if the URL would be larger than the buffer.

gint dmesh_fill_alternate ( const struct sha1 * sha1,

gnet_host_t * hvec,

gint hcnt

)

Fill supplied vector `hvec' whose size is `hcnt' with some alternate locations for a given SHA1 key, that can be requested by hash directly.

Returns:
the amount of locations filled.

void dmesh_fill_info ( dmesh_urlinfo_t * info,

const struct sha1 * sha1,

const host_addr_t addr,

guint16 port,

guint idx,

const gchar * name

) [static]

Fill URL info from externally supplied sha1, addr, port, idx and name.
If sha1 is NULL, we use the name, otherwise the urn:sha1.
WARNING: fills structure with pointers to static data.

gboolean dmesh_free_kv ( gpointer key,

gpointer value,

gpointer unused_udata

) [static]

Free key/value pair in download mesh hash.

void dmesh_good_mark ( const struct sha1 * sha1,

host_addr_t addr,

guint16 port,

gboolean good

)

Flag dmesh entry for this SHA1, address and port as good or bad.

void dmesh_header_print ( FILE * out ) [static]

Prints header to dmesh store file.

void dmesh_init ( void )

Initialize the download mesh.

gboolean dmesh_is_banned ( const dmesh_urlinfo_t * info ) [static]

Check whether URL is banned from the mesh.

void dmesh_multiple_downloads ( const struct sha1 * sha1,

filesize_t size,

fileinfo_t * fi

)

This is called when swarming is first requested to get a list of all the servers with the requested file known by dmesh.
It creates a new download for every server found.

Parameters:

`sha1' (atom) the SHA1 of the file.

`size' the original file size.

`fi' no brief description.

void dmesh_negative_alt ( const struct sha1 * sha1,

host_addr_t reporter,

host_addr_t addr,

guint16 port

)

Record that addr:port was signalled negatively as an alternate location for given sha1.
The reporter's address is also given so that we can wait until we have sufficient evidence from at least 2 different parties.
When there is sufficient evidence, the entry is evicted from the mesh and placed into the banned mesh.

void dmesh_parse_addr_port_list ( const struct sha1 * sha1,

const gchar * value,

dmesh_add_cb func,

gpointer udata

) [static]

Parse a list of addr:port, such as typically found in "X-Alt" or "X-Nalt" headers to extract alternate sources.
For each value found, invoke the supplied callback `func' as:
func(sha1, addr, port, udata);
where udata is opaque user-supplied data.

gboolean dmesh_raw_add ( const struct sha1 * sha1,

const dmesh_urlinfo_t * info,

time_t stamp

) [static]

Add entry to the download mesh, indexed by the binary `sha1' digest.
If `stamp' is 0, then the current time is used.
If `idx' is URN_INDEX, then we can access this file only through an /uri-res request, the URN being given as `name'.

Returns:
whether the entry was added in the mesh, or was discarded because it was the oldest record and we have enough already.

gboolean dmesh_remove ( const struct sha1 * sha1,

const host_addr_t addr,

guint16 port,

guint idx,

const gchar * name

)

Remove entry from mesh due to a failed download attempt.

void dmesh_remove_alternate ( const struct sha1 * sha1,

host_addr_t addr,

guint16 port

)

Remove addr:port as a known alternate location for given sha1.
This inserts the location into the banned mesh.

void dmesh_retrieve ( void ) [static]

Retrieve download mesh and add entries that have not expired yet.
The mesh is normally retrieved from ~/.gtk-gnutella/dmesh.

void dmesh_store ( void )

Store download mesh onto file.
The download mesh is normally stored in ~/.gtk-gnutella/dmesh.

void dmesh_store_hash ( const gchar * what,

GHashTable * hash,

const gchar * file,

header_func_t header_cb,

GHFunc store_cb

) [static]

Store hash table `hash' into `file'.
The file header is emitted by `header_cb'. The storing callback for each item is `store_cb'.

void dmesh_store_kv ( gpointer key,

gpointer value,

gpointer udata

) [static]

Store key/value pair in file.

gboolean dmesh_url_parse ( const gchar * url,

dmesh_urlinfo_t * info

)

Parse URL `url', and fill a structure `info' representing this URL.

Returns:
TRUE if OK, FALSE if we could not parse it. The variable `dmesh_url_errno' is set accordingly.

const gchar* dmesh_url_strerror ( dmesh_url_error_t errnum )

Returns:
human-readable error string corresponding to error code `errnum'.

size_t dmesh_urlinfo ( const dmesh_urlinfo_t * info,

gchar * buf,

size_t len,

gboolean * quoting

) [static]

Format the URL described by `info' into the provided buffer `buf', which can hold `len' bytes.

Returns:
length of formatted entry, -1 if the URL would be larger than the buffer. If `quoting' is non-NULL, set it to indicate whether the formatted URL should be quoted if emitted in a header, because it contains a "," character.

void dmesh_urlinfo_free ( dmesh_urlinfo_t * info ) [static]

Free a dmesh_urlinfo_t structure.

gchar * dmesh_urlinfo_to_string ( const dmesh_urlinfo_t * info ) [static]

Format the `info' URL and return pointer to static string.

gint urlinfo_eq ( gconstpointer a,

gconstpointer b

) [static]

Test equality of two URL infos.

guint urlinfo_hash ( gconstpointer key ) [static]

Hash a URL info.

Variable Documentation

GHashTable* ban_mesh = NULL [static]

If we get a "bad" URL into the mesh ("bad" = gives 404 or other error when trying to download it), we must remember it for some time and prevent it from re-entering the mesh again within that period to prevent rescheduling for download and a further failure: that would be hammering the poor host, and we're wasting our time and bandwidth.
Therefore, each time we get a "bad" URL, we insert it in a hash table. The table entry is then scheduled to be removed after some grace period occurs. The table is keyed by the dmesh_urlinfo_t, and points to a dmesh_banned structure.
The table is persisted at regular intervals.

GHashTable* ban_mesh_by_sha1 = NULL [static]

This table stores the banned entries by SHA1.

const gchar dmesh_ban_file[] = "dmesh_ban" [static]

const gchar dmesh_file[] = "dmesh" [static]

dmesh_url_error_t dmesh_url_errno

Error from dmesh_url_parse().

GHashTable* mesh = NULL [static]

The download mesh records all the known sources for a given SHA1.
It is implemented as a big hash table, where SHA1 are keys, each value being a struct dmesh pointer.

const gchar* const parse_errstr[] [static]

Initial value:
{ "OK", "HTTP parsing error", "File prefix neither /uri-res nor /get", "Index in /get/index is reserved", "No filename after /get/index", "Bad URL encoding", "Malformed /uri-res/N2R?", }

Generated on Sat Jun 30 17:53:25 2007 for gtk-gnutella by

1.3.9.1


Data Structures
struct	dmesh
struct	dmesh_entry
struct	dmesh_banned
Defines
#define	MAX_LIFETIME 86400
	1 day
#define	MAX_ENTRIES 256
	Max amount of entries kept per SHA1.
#define	MIN_PFSP_SIZE 524288
	512K, min size for PFSP advertising
#define	MIN_PFSP_PCT 10
	10%, min available data for PFSP
#define	MIN_BAD_REPORT 2
	Don't ban before that many X-Nalt.
#define	BAN_LIFETIME 7200
	2 hours
#define	DMESH_MAX MAX_ENTRIES
Typedefs
typedef void(*	dmesh_add_cb )(const struct sha1 *sha1, host_addr_t addr, guint16 port, gpointer udata)
typedef void(*	header_func_t )(FILE *out)
Functions
void	dmesh_retrieve (void)
	Retrieve download mesh and add entries that have not expired yet.
void	dmesh_ban_retrieve (void)
	Retrieve banned mesh and add entries that have not expired yet.
gchar *	dmesh_urlinfo_to_string (const dmesh_urlinfo_t *info)
	Format the `info' URL and return pointer to static string.
guint	urlinfo_hash (gconstpointer key)
	Hash a URL info.
gint	urlinfo_eq (gconstpointer a, gconstpointer b)
	Test equality of two URL infos.
void	dmesh_init (void)
	Initialize the download mesh.
void	dmesh_entry_free (struct dmesh_entry *dme)
	Free download mesh entry.
void	dmesh_fill_info (dmesh_urlinfo_t info, const struct sha1 sha1, const host_addr_t addr, guint16 port, guint idx, const gchar *name)
	Fill URL info from externally supplied sha1, addr, port, idx and name.
void	dmesh_urlinfo_free (dmesh_urlinfo_t *info)
	Free a dmesh_urlinfo_t structure.
void	dmesh_ban_remove_entry (struct dmesh_banned *dmb)
	Remove entry from banned mesh.
void	dmesh_ban_expire (cqueue_t *unused_cq, gpointer obj)
	Called from callout queue when it's time to expire the URL ban.
void	dmesh_ban_add (const struct sha1 sha1, dmesh_urlinfo_t info, time_t stamp)
	Add new URL to the banned hash.
void	dmesh_ban_remove (const struct sha1 *sha1, host_addr_t addr, guint16 port)
	Forcefully remove an entry from the banned mesh.
gboolean	dmesh_is_banned (const dmesh_urlinfo_t *info)
	Check whether URL is banned from the mesh.
const gchar *	dmesh_url_strerror (dmesh_url_error_t errnum)
gboolean	dmesh_url_parse (const gchar url, dmesh_urlinfo_t info)
	Parse URL `url', and fill a structure `info' representing this URL.
dmesh *	dm_alloc (const struct sha1 *sha1)
	Allocate a new download mesh structure (there is one per SHA1).
void	dm_free (struct dmesh *dm)
	Free download mesh structure.
void	dm_remove_entry (struct dmesh dm, struct dmesh_entry dme)
	Remove specified entry from mesh bucket and reclaim it.
void	dm_remove (struct dmesh *dm, const host_addr_t addr, guint16 port)
	Remove the addr:port entry from mesh bucket, if present.
void	dm_expire (struct dmesh *dm, glong agemax)
	Expire entries older than `agemax' in a given mesh bucket `dm'.
void	dmesh_dispose (const struct sha1 *sha1)
	Dispose of the entry slot, which must be empty.
gboolean	dmesh_remove (const struct sha1 sha1, const host_addr_t addr, guint16 port, guint idx, const gchar name)
	Remove entry from mesh due to a failed download attempt.
gint	dmesh_count (const struct sha1 *sha1)
	Get the number of dmesh entries for a given SHA1.
gboolean	dmesh_raw_add (const struct sha1 sha1, const dmesh_urlinfo_t info, time_t stamp)
	Add entry to the download mesh, indexed by the binary `sha1' digest.
gboolean	dmesh_add (const struct sha1 sha1, const host_addr_t addr, guint16 port, guint idx, const gchar name, time_t stamp)
	Same as dmesh_raw_add(), but this is for public consumption.
void	dmesh_add_alternate (const struct sha1 *sha1, host_addr_t addr, guint16 port)
	Add addr:port as a known alternate location for given sha1.
void	dmesh_add_good_alternate (const struct sha1 *sha1, host_addr_t addr, guint16 port)
void	dmesh_add_alternates (const struct sha1 sha1, const gnet_host_vec_t alt)
	Add a set of alternate locations (IP + port) to the mesh.
void	dmesh_remove_alternate (const struct sha1 *sha1, host_addr_t addr, guint16 port)
	Remove addr:port as a known alternate location for given sha1.
void	dmesh_negative_alt (const struct sha1 *sha1, host_addr_t reporter, host_addr_t addr, guint16 port)
	Record that addr:port was signalled negatively as an alternate location for given sha1.
void	dmesh_good_mark (const struct sha1 *sha1, host_addr_t addr, guint16 port, gboolean good)
	Flag dmesh entry for this SHA1, address and port as good or bad.
size_t	dmesh_urlinfo (const dmesh_urlinfo_t info, gchar buf, size_t len, gboolean *quoting)
	Format the URL described by `info' into the provided buffer `buf', which can hold `len' bytes.
size_t	dmesh_entry_compact (const struct dmesh_entry dme, gchar buf, size_t size)
	Format mesh_entry in the provided buffer, as a compact addr:port address.
size_t	dmesh_entry_url_stamp (const struct dmesh_entry dme, gchar buf, size_t size)
	Format dmesh_entry in the provided buffer, as an URL with an appended timestamp in ISO format, GMT time.
const gchar *	dmesh_entry_to_string (const struct dmesh_entry *dme)
	Format the `dme' mesh entry as "URL timestamp".
gint	dmesh_fill_alternate (const struct sha1 sha1, gnet_host_t hvec, gint hcnt)
	Fill supplied vector `hvec' whose size is `hcnt' with some alternate locations for a given SHA1 key, that can be requested by hash directly.
gint	dmesh_alternate_location (const struct sha1 sha1, gchar buf, size_t size, const host_addr_t addr, time_t last_sent, const gchar vendor, fileinfo_t fi, gboolean request)
	Build alternate location header for a given SHA1 key.
gboolean	dmesh_collect_sha1 (const gchar value, struct sha1 sha1)
	Parse the value of the X-Gnutella-Content-URN header in `value', looking for a SHA1.
void	dmesh_parse_addr_port_list (const struct sha1 sha1, const gchar value, dmesh_add_cb func, gpointer udata)
	Parse a list of addr:port, such as typically found in "X-Alt" or "X-Nalt" headers to extract alternate sources.
void	dmesh_collect_compact_locations_cback (const struct sha1 *sha1, host_addr_t addr, guint16 port, gpointer unused_udata)
void	dmesh_collect_compact_locations (const struct sha1 sha1, const gchar value)
	Parse the value of the "X-Alt" header to extract alternate sources for a given SHA1 key given in the new compact form.
void	dmesh_collect_negative_locations_cback (const struct sha1 *sha1, host_addr_t addr, guint16 port, gpointer udata)
void	dmesh_collect_negative_locations (const struct sha1 sha1, const gchar value, host_addr_t reporter)
	Parse the value of the "X-Nalt" header to extract bad sources for a given SHA1 key, given in the new compact form.
void	dmesh_collect_locations (const struct sha1 sha1, const gchar value)
	Parse value of the "X-Gnutella-Alternate-Location" to extract alternate sources for a given SHA1 key.
gint	dmesh_alt_loc_fill (const struct sha1 sha1, dmesh_urlinfo_t buf, gint count)
	Fill buffer with at most `count' alternative locations for sha1.
void	dmesh_check_results_set (gnet_results_set_t *rs)
	Parse query hit (result set) for entries whose SHA1 match something we have into the mesh or share, and insert them if needed.
void	dmesh_multiple_downloads (const struct sha1 sha1, filesize_t size, fileinfo_t fi)
	This is called when swarming is first requested to get a list of all the servers with the requested file known by dmesh.
void	dmesh_store_kv (gpointer key, gpointer value, gpointer udata)
	Store key/value pair in file.
void	dmesh_store_hash (const gchar what, GHashTable hash, const gchar *file, header_func_t header_cb, GHFunc store_cb)
	Store hash table `hash' into `file'.
void	dmesh_header_print (FILE *out)
	Prints header to dmesh store file.
void	dmesh_store (void)
	Store download mesh onto file.
void	dmesh_ban_store_kv (gpointer key, gpointer value, gpointer udata)
	Store key/value pair in file.
void	dmesh_ban_header_print (FILE *out)
	Prints header to banned mesh store file.
void	dmesh_ban_store (void)
	Store banned mesh onto file.
gboolean	dmesh_free_kv (gpointer key, gpointer value, gpointer unused_udata)
	Free key/value pair in download mesh hash.
void	dmesh_ban_prepend_list (gpointer key, gpointer value, gpointer user)
	Prepend the value to the list, given by reference.
void	dmesh_close (void)
	Called at servent shutdown time.
Variables
dmesh_url_error_t	dmesh_url_errno
	Error from dmesh_url_parse().
GHashTable *	mesh = NULL
	The download mesh records all the known sources for a given SHA1.
const gchar	dmesh_file [] = "dmesh"
GHashTable *	ban_mesh = NULL
	If we get a "bad" URL into the mesh ("bad" = gives 404 or other error when trying to download it), we must remember it for some time and prevent it from re-entering the mesh again within that period to prevent rescheduling for download and a further failure: that would be hammering the poor host, and we're wasting our time and bandwidth.
GHashTable *	ban_mesh_by_sha1 = NULL
	This table stores the banned entries by SHA1.
const gchar	dmesh_ban_file [] = "dmesh_ban"
const gchar *const	parse_errstr []