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libalias: tidy up housekeeping

Replace current expensive, but sparsly called housekeeping
by a single, repetive action.

This is part of a larger restructure of libalias in order to switch to
more efficient data structures.  The whole restructure process is
split into 15 reviews to ease reviewing.  All those steps will be
squashed into a single commit for MFC in order to hide the
intermediate states from production systems.

Reviewed by:	hselasky
MFC after:	1 week
Differential Revision: https://reviews.freebsd.org/D30277
This commit is contained in:
Lutz Donnerhacke 2021-05-15 17:35:36 +02:00
parent b47f461c8e
commit 294799c6b0
2 changed files with 53 additions and 69 deletions

View File

@ -182,11 +182,6 @@ static LIST_HEAD(, libalias) instancehead = LIST_HEAD_INITIALIZER(instancehead);
near relevant functions or structs)
*/
/* Parameters used for cleanup of expired links */
/* NOTE: ALIAS_CLEANUP_INTERVAL_SECS must be less then LINK_TABLE_OUT_SIZE */
#define ALIAS_CLEANUP_INTERVAL_SECS 64
#define ALIAS_CLEANUP_MAX_SPOKES (LINK_TABLE_OUT_SIZE/5)
/* Timeouts (in seconds) for different link types */
#define ICMP_EXPIRE_TIME 60
#define UDP_EXPIRE_TIME 60
@ -329,6 +324,7 @@ struct alias_link {
/* Linked list of pointers for input and output lookup tables */
LIST_ENTRY (alias_link) list_out;
LIST_ENTRY (alias_link) list_in;
TAILQ_ENTRY (alias_link) list_expire;
/* Auxiliary data */
union {
char *frag_ptr;
@ -510,7 +506,7 @@ Port Allocation:
Link creation and deletion:
CleanupAliasData() - remove all link chains from lookup table
IncrementalCleanup() - look for stale links in a single chain
CleanupLink() - look for a stale link
DeleteLink() - remove link
AddLink() - add link
ReLink() - change link
@ -529,8 +525,8 @@ static int GetNewPort(struct libalias *, struct alias_link *, int);
static u_short GetSocket(struct libalias *, u_short, int *, int);
#endif
static void CleanupAliasData(struct libalias *);
static void IncrementalCleanup(struct libalias *);
static void DeleteLink(struct alias_link *);
static void CleanupLink(struct libalias *, struct alias_link **);
static void DeleteLink(struct alias_link **);
static struct alias_link *
ReLink(struct alias_link *,
@ -806,42 +802,39 @@ FindNewPortGroup(struct libalias *la,
static void
CleanupAliasData(struct libalias *la)
{
struct alias_link *lnk;
int i;
LIBALIAS_LOCK_ASSERT(la);
for (i = 0; i < LINK_TABLE_OUT_SIZE; i++) {
lnk = LIST_FIRST(&la->linkTableOut[i]);
while (lnk != NULL) {
struct alias_link *link_next = LIST_NEXT(lnk, list_out);
DeleteLink(lnk);
lnk = link_next;
}
}
la->cleanupIndex = 0;
}
static void
IncrementalCleanup(struct libalias *la)
{
struct alias_link *lnk, *lnk_tmp;
LIBALIAS_LOCK_ASSERT(la);
LIST_FOREACH_SAFE(lnk, &la->linkTableOut[la->cleanupIndex++],
list_out, lnk_tmp) {
if (la->timeStamp - lnk->timestamp > lnk->expire_time)
DeleteLink(lnk);
}
if (la->cleanupIndex == LINK_TABLE_OUT_SIZE)
la->cleanupIndex = 0;
/* permanent entries may stay */
TAILQ_FOREACH_SAFE(lnk, &la->checkExpire, list_expire, lnk_tmp)
DeleteLink(&lnk);
}
static void
DeleteLink(struct alias_link *lnk)
CleanupLink(struct libalias *la, struct alias_link **lnk)
{
LIBALIAS_LOCK_ASSERT(la);
if (lnk == NULL || *lnk == NULL)
return;
if (la->timeStamp - (*lnk)->timestamp > (*lnk)->expire_time) {
DeleteLink(lnk);
if ((*lnk) == NULL)
return;
}
/* move to end, swap may fail on a single entry list */
TAILQ_REMOVE(&la->checkExpire, (*lnk), list_expire);
TAILQ_INSERT_TAIL(&la->checkExpire, (*lnk), list_expire);
}
static void
DeleteLink(struct alias_link **plnk)
{
struct alias_link *lnk = *plnk;
struct libalias *la = lnk->la;
LIBALIAS_LOCK_ASSERT(la);
@ -869,6 +862,10 @@ DeleteLink(struct alias_link *lnk)
/* Adjust input table pointers */
LIST_REMOVE(lnk, list_in);
/* remove from housekeeping */
TAILQ_REMOVE(&la->checkExpire, lnk, list_expire);
#ifndef NO_USE_SOCKETS
/* Close socket, if one has been allocated */
if (lnk->sockfd != -1) {
@ -908,6 +905,7 @@ DeleteLink(struct alias_link *lnk)
/* Free memory */
free(lnk);
*plnk = NULL;
/* Write statistics, if logging enabled */
if (la->packetAliasMode & PKT_ALIAS_LOG) {
@ -1039,6 +1037,9 @@ AddLink(struct libalias *la, struct in_addr src_addr, struct in_addr dst_addr,
/* Set up pointers for input lookup table */
start_point = StartPointIn(alias_addr, lnk->alias_port, link_type);
LIST_INSERT_HEAD(&la->linkTableIn[start_point], lnk, list_in);
/* Include the element into the housekeeping list */
TAILQ_INSERT_TAIL(&la->checkExpire, lnk, list_expire);
} else {
#ifdef LIBALIAS_DEBUG
fprintf(stderr, "PacketAlias/AddLink(): ");
@ -1079,7 +1080,7 @@ ReLink(struct alias_link *old_lnk,
PunchFWHole(new_lnk);
}
#endif
DeleteLink(old_lnk);
DeleteLink(&old_lnk);
return (new_lnk);
}
@ -1102,12 +1103,14 @@ _FindLinkOut(struct libalias *la, struct in_addr src_addr,
lnk->src_port == src_port &&
lnk->dst_port == dst_port &&
lnk->link_type == link_type &&
lnk->server == NULL) {
lnk->timestamp = la->timeStamp;
lnk->server == NULL)
break;
}
}
CleanupLink(la, &lnk);
if (lnk != NULL)
lnk->timestamp = la->timeStamp;
/* Search for partially specified links. */
if (lnk == NULL && replace_partial_links) {
if (dst_port != 0 && dst_addr.s_addr != INADDR_ANY) {
@ -1235,6 +1238,7 @@ _FindLinkIn(struct libalias *la, struct in_addr dst_addr,
}
}
CleanupLink(la, &lnk_fully_specified);
if (lnk_fully_specified != NULL) {
lnk_fully_specified->timestamp = la->timeStamp;
lnk = lnk_fully_specified;
@ -1572,6 +1576,7 @@ FindPptpOutByCallId(struct libalias *la, struct in_addr src_addr,
lnk->src_port == src_call_id)
break;
CleanupLink(la, &lnk);
return (lnk);
}
@ -1592,6 +1597,7 @@ FindPptpOutByPeerCallId(struct libalias *la, struct in_addr src_addr,
lnk->dst_port == dst_call_id)
break;
CleanupLink(la, &lnk);
return (lnk);
}
@ -1612,6 +1618,7 @@ FindPptpInByCallId(struct libalias *la, struct in_addr dst_addr,
lnk->dst_port == dst_call_id)
break;
CleanupLink(la, &lnk);
return (lnk);
}
@ -2038,7 +2045,7 @@ SetExpire(struct alias_link *lnk, int expire)
{
if (expire == 0) {
lnk->flags &= ~LINK_PERMANENT;
DeleteLink(lnk);
DeleteLink(&lnk);
} else if (expire == -1) {
lnk->flags |= LINK_PERMANENT;
} else if (expire > 0) {
@ -2094,7 +2101,7 @@ SetDestCallId(struct alias_link *lnk, u_int16_t cid)
void
HouseKeeping(struct libalias *la)
{
int i, n;
struct alias_link * lnk = TAILQ_FIRST(&la->checkExpire);
#ifndef _KERNEL
struct timeval tv;
#endif
@ -2111,25 +2118,7 @@ HouseKeeping(struct libalias *la)
gettimeofday(&tv, NULL);
la->timeStamp = tv.tv_sec;
#endif
/* Compute number of spokes (output table link chains) to cover */
n = LINK_TABLE_OUT_SIZE * (la->timeStamp - la->lastCleanupTime);
n /= ALIAS_CLEANUP_INTERVAL_SECS;
/* Handle different cases */
if (n > 0) {
if (n > ALIAS_CLEANUP_MAX_SPOKES)
n = ALIAS_CLEANUP_MAX_SPOKES;
la->lastCleanupTime = la->timeStamp;
for (i = 0; i < n; i++)
IncrementalCleanup(la);
} else if (n < 0) {
#ifdef LIBALIAS_DEBUG
fprintf(stderr, "PacketAlias/HouseKeeping(): ");
fprintf(stderr, "something unexpected in time values\n");
#endif
la->lastCleanupTime = la->timeStamp;
}
CleanupLink(la, &lnk);
}
/* Init the log file and enable logging */
@ -2356,7 +2345,7 @@ LibAliasRedirectDelete(struct libalias *la, struct alias_link *lnk)
{
LIBALIAS_LOCK(la);
la->deleteAllLinks = 1;
DeleteLink(lnk);
DeleteLink(&lnk);
la->deleteAllLinks = 0;
LIBALIAS_UNLOCK(la);
}
@ -2426,17 +2415,16 @@ LibAliasInit(struct libalias *la)
#ifdef _KERNEL
la->timeStamp = time_uptime;
la->lastCleanupTime = time_uptime;
#else
gettimeofday(&tv, NULL);
la->timeStamp = tv.tv_sec;
la->lastCleanupTime = tv.tv_sec;
#endif
for (i = 0; i < LINK_TABLE_OUT_SIZE; i++)
LIST_INIT(&la->linkTableOut[i]);
for (i = 0; i < LINK_TABLE_IN_SIZE; i++)
LIST_INIT(&la->linkTableIn[i]);
TAILQ_INIT(&la->checkExpire);
#ifdef _KERNEL
AliasSctpInit(la);
#endif
@ -2466,8 +2454,6 @@ LibAliasInit(struct libalias *la)
la->fragmentPtrLinkCount = 0;
la->sockCount = 0;
la->cleanupIndex = 0;
la->packetAliasMode = PKT_ALIAS_SAME_PORTS
#ifndef NO_USE_SOCKETS
| PKT_ALIAS_USE_SOCKETS

View File

@ -94,6 +94,8 @@ struct libalias {
* output lookup tables. */
LIST_HEAD (, alias_link) linkTableOut[LINK_TABLE_OUT_SIZE];
LIST_HEAD (, alias_link) linkTableIn[LINK_TABLE_IN_SIZE];
/* HouseKeeping */
TAILQ_HEAD (, alias_link) checkExpire;
/* Link statistics */
int icmpLinkCount;
int udpLinkCount;
@ -103,12 +105,8 @@ struct libalias {
int fragmentIdLinkCount;
int fragmentPtrLinkCount;
int sockCount;
/* Index to chain of link table being inspected for old links */
int cleanupIndex;
/* System time in seconds for current packet */
int timeStamp;
/* Last time IncrementalCleanup() was called */
int lastCleanupTime;
/* If equal to zero, DeleteLink()
* will not remove permanent links */
int deleteAllLinks;