--- /dev/null
+/*
+ * IRC - Internet Relay Chat, ircd/msgq.c
+ * Copyright (C) 2000 Kevin L. Mitchell <klmitch@mit.edu>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 1, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+/** @file
+ * @brief Outbound message queue implementation.
+ * @version $Id$
+ */
+#include "config.h"
+
+#include "msgq.h"
+#include "ircd.h"
+#include "ircd_alloc.h"
+#include "ircd_defs.h"
+#include "ircd_features.h"
+#include "ircd_log.h"
+#include "ircd_reply.h"
+#include "ircd_snprintf.h"
+#include "numeric.h"
+#include "send.h"
+#include "s_debug.h"
+#include "s_stats.h"
+
+/* #include <assert.h> -- Now using assert in ircd_log.h */
+#include <stdarg.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/uio.h> /* struct iovec */
+
+#define MB_BASE_SHIFT 5 /**< Log2 of smallest message body to allocate. */
+#define MB_MAX_SHIFT 9 /**< Log2 of largest message body to allocate. */
+
+/** Buffer for a single message. */
+struct MsgBuf {
+ struct MsgBuf *next; /**< next msg in global queue */
+ struct MsgBuf **prev_p; /**< what points to us in linked list */
+ struct MsgBuf *real; /**< the actual MsgBuf we're attaching */
+ unsigned int ref; /**< reference count */
+ unsigned int length; /**< length of message */
+ unsigned int power; /**< size of buffer (power of 2) */
+ char msg[1]; /**< the message */
+};
+
+/** Return allocated length of the buffer of \a buf. */
+#define bufsize(buf) (1 << (buf)->power)
+
+/** Message body for a particular destination. */
+struct Msg {
+ struct Msg *next; /**< next msg */
+ unsigned int sent; /**< bytes in msg that have already been sent */
+ struct MsgBuf *msg; /**< actual message in queue */
+};
+
+/** Statistics tracking for message sizes. */
+struct MsgSizes {
+ unsigned int msgs; /**< total number of messages */
+ unsigned int sizes[BUFSIZE]; /**< histogram of message sizes */
+};
+
+/** Global tracking data for message buffers. */
+static struct {
+ struct MsgBuf *msglist; /**< list of in-use MsgBuf's */
+ struct {
+ unsigned int alloc; /**< number of Msg's allocated */
+ unsigned int used; /**< number of Msg's in use */
+ struct Msg *free; /**< freelist of Msg's */
+ } msgs; /**< tracking info for Msg structs */
+ size_t tot_bufsize; /**< total amount of memory in buffers */
+ /** Array of MsgBuf information, one entry for each used bucket size. */
+ struct {
+ unsigned int alloc; /**< total MsgBuf's of this size */
+ unsigned int used; /**< number of MsgBuf's of this size in use */
+ struct MsgBuf *free; /**< list of free MsgBuf's */
+ } msgBufs[MB_MAX_SHIFT - MB_BASE_SHIFT + 1];
+ struct MsgSizes sizes; /**< histogram of message sizes */
+} MQData;
+
+/*
+ * This routine is used to remove a certain amount of data from a given
+ * queue and release the Msg (and MsgBuf) structure if needed
+ */
+/** Remove some data from a list within a message queue.
+ * @param[in,out] mq Message queue to remove from.
+ * @param[in,out] qlist Particular list within queue to remove from.
+ * @param[in,out] length_p Number of bytes left to remove.
+ */
+static void
+msgq_delmsg(struct MsgQ *mq, struct MsgQList *qlist, unsigned int *length_p)
+{
+ struct Msg *m;
+ unsigned int msglen;
+
+ assert(0 != mq);
+ assert(0 != qlist);
+ assert(0 != qlist->head);
+ assert(0 != length_p);
+
+ m = qlist->head; /* find the msg we're deleting from */
+
+ msglen = m->msg->length - m->sent; /* calculate how much is left */
+
+ if (*length_p >= msglen) { /* deleted it all? */
+ mq->length -= msglen; /* decrement length */
+ mq->count--; /* decrement the message count */
+ *length_p -= msglen;
+
+ msgq_clean(m->msg); /* free up the struct MsgBuf */
+ m->msg = 0; /* don't let it point anywhere nasty, please */
+
+ if (qlist->head == qlist->tail) /* figure out if we emptied the queue */
+ qlist->head = qlist->tail = 0;
+ else
+ qlist->head = m->next; /* just shift the list down some */
+
+ MQData.msgs.used--; /* struct Msg is not in use anymore */
+
+ m->next = MQData.msgs.free; /* throw it onto the free list */
+ MQData.msgs.free = m;
+ } else {
+ mq->length -= *length_p; /* decrement queue length */
+ m->sent += *length_p; /* this much of the message has been sent */
+ *length_p = 0; /* we've dealt with it all */
+ }
+}
+
+/** Initialize \a mq.
+ * @param[in] mq MsgQ to initialize.
+ */
+void
+msgq_init(struct MsgQ *mq)
+{
+ assert(0 != mq);
+
+ mq->length = 0;
+ mq->count = 0;
+ mq->queue.head = 0;
+ mq->queue.tail = 0;
+ mq->prio.head = 0;
+ mq->prio.tail = 0;
+}
+
+/** Delete bytes from the front of a message queue.
+ * @param[in] mq Queue to drop data from.
+ * @param[in] length Number of bytes to drop.
+ */
+void
+msgq_delete(struct MsgQ *mq, unsigned int length)
+{
+ assert(0 != mq);
+
+ while (length > 0) {
+ if (mq->queue.head && mq->queue.head->sent > 0) /* partial msg on norm q */
+ msgq_delmsg(mq, &mq->queue, &length);
+ else if (mq->prio.head) /* message (partial or complete) on prio queue */
+ msgq_delmsg(mq, &mq->prio, &length);
+ else if (mq->queue.head) /* message on normal queue */
+ msgq_delmsg(mq, &mq->queue, &length);
+ else
+ break;
+ }
+}
+
+/** Map data from a message queue to an I/O vector.
+ * @param[in] mq Message queue to send from.
+ * @param[out] iov Output vector.
+ * @param[in] count Number of elements in \a iov.
+ * @param[out] len Number of bytes mapped from \a mq to \a iov.
+ * @return Number of elements filled in \a iov.
+ */
+int
+msgq_mapiov(const struct MsgQ *mq, struct iovec *iov, int count,
+ unsigned int *len)
+{
+ struct Msg *queue;
+ struct Msg *prio;
+ int i = 0;
+
+ assert(0 != mq);
+ assert(0 != iov);
+ assert(0 != count);
+ assert(0 != len);
+
+ if (mq->length <= 0) /* no data to map */
+ return 0;
+
+ if (mq->queue.head && mq->queue.head->sent > 0) { /* partial msg on norm q */
+ iov[i].iov_base = mq->queue.head->msg->msg + mq->queue.head->sent;
+ iov[i].iov_len = mq->queue.head->msg->length - mq->queue.head->sent;
+ *len += iov[i].iov_len;
+
+ queue = mq->queue.head->next; /* where we start later... */
+
+ i++; /* filled an iovec... */
+ if (!--count) /* check for space */
+ return i;
+ } else
+ queue = mq->queue.head; /* start at head of queue */
+
+ if (mq->prio.head && mq->prio.head->sent > 0) { /* partial msg on prio q */
+ iov[i].iov_base = mq->prio.head->msg->msg + mq->prio.head->sent;
+ iov[i].iov_len = mq->prio.head->msg->length - mq->prio.head->sent;
+ *len += iov[i].iov_len;
+
+ prio = mq->prio.head->next; /* where we start later... */
+
+ i++; /* filled an iovec... */
+ if (!--count) /* check for space */
+ return i;
+ } else
+ prio = mq->prio.head; /* start at head of prio */
+
+ for (; prio; prio = prio->next) { /* go through prio queue */
+ iov[i].iov_base = prio->msg->msg; /* store message */
+ iov[i].iov_len = prio->msg->length;
+ *len += iov[i].iov_len;
+
+ i++; /* filled an iovec... */
+ if (!--count) /* check for space */
+ return i;
+ }
+
+ for (; queue; queue = queue->next) { /* go through normal queue */
+ iov[i].iov_base = queue->msg->msg;
+ iov[i].iov_len = queue->msg->length;
+ *len += iov[i].iov_len;
+
+ i++; /* filled an iovec... */
+ if (!--count) /* check for space */
+ return i;
+ }
+
+ return i;
+}
+
+/** Allocate a message buffer large enough to hold \a length bytes.
+ * TODO: \a in_mb needs better documentation.
+ * @param[in] in_mb Some other message buffer(?).
+ * @param[in] length Number of bytes of space to reserve in output.
+ * @return Pointer to some usable message buffer.
+ */
+static struct MsgBuf *
+msgq_alloc(struct MsgBuf *in_mb, int length)
+{
+ struct MsgBuf *mb;
+ int power;
+
+ /* Find the power of two size that will accommodate the message */
+ for (power = MB_BASE_SHIFT; power < MB_MAX_SHIFT + 1; power++)
+ if ((length - 1) >> power == 0)
+ break;
+ assert((1 << power) >= length);
+ assert((1 << power) <= 512);
+ length = 1 << power; /* reset the length */
+
+ /* If the message needs a buffer of exactly the existing size, just use it */
+ if (in_mb && in_mb->power == power) {
+ in_mb->real = in_mb; /* real buffer is this buffer */
+ return in_mb;
+ }
+
+ /* Try popping one off the freelist first */
+ if ((mb = MQData.msgBufs[power - MB_BASE_SHIFT].free)) {
+ MQData.msgBufs[power - MB_BASE_SHIFT].free = mb->next;
+ } else if (MQData.tot_bufsize < feature_int(FEAT_BUFFERPOOL)) {
+ /* Allocate another if we won't bust the BUFFERPOOL */
+ Debug((DEBUG_MALLOC, "Allocating MsgBuf of length %d (total size %zu)",
+ length, sizeof(struct MsgBuf) + length));
+ mb = (struct MsgBuf *)MyMalloc(sizeof(struct MsgBuf) + length);
+ MQData.msgBufs[power - MB_BASE_SHIFT].alloc++;
+ mb->power = power; /* remember size */
+ MQData.tot_bufsize += length;
+ }
+
+ if (mb) {
+ MQData.msgBufs[power - MB_BASE_SHIFT].used++; /* how many are we using? */
+
+ mb->real = 0; /* essential initializations */
+ mb->ref = 1;
+
+ if (in_mb) /* remember who's the *real* buffer */
+ in_mb->real = mb;
+ } else if (in_mb) /* just use the input buffer */
+ mb = in_mb->real = in_mb;
+
+ return mb; /* return the buffer */
+}
+
+/** Deallocate unused message buffers.
+ */
+static void
+msgq_clear_freembs(void)
+{
+ struct MsgBuf *mb;
+ int i;
+
+ /* Walk through the various size classes */
+ for (i = MB_BASE_SHIFT; i < MB_MAX_SHIFT + 1; i++)
+ /* walk down the free list */
+ while ((mb = MQData.msgBufs[i - MB_BASE_SHIFT].free)) {
+ MQData.msgBufs[i - MB_BASE_SHIFT].free = mb->next; /* shift free list */
+ MQData.msgBufs[i - MB_BASE_SHIFT].alloc--; /* reduce allocation count */
+ MQData.tot_bufsize -= 1 << i; /* reduce total buffer allocation count */
+ MyFree(mb); /* and free the buffer */
+ }
+}
+
+/** Format a message buffer for a client from a format string.
+ * @param[in] dest %Client that receives the data (may be NULL).
+ * @param[in] format Format string for message.
+ * @param[in] vl Argument list for \a format.
+ * @return Allocated MsgBuf.
+ */
+struct MsgBuf *
+msgq_vmake(struct Client *dest, const char *format, va_list vl)
+{
+ struct MsgBuf *mb;
+
+ assert(0 != format);
+
+ if (!(mb = msgq_alloc(0, BUFSIZE))) {
+ if (feature_bool(FEAT_HAS_FERGUSON_FLUSHER)) {
+ /*
+ * from "Married With Children" episode were Al bought a REAL toilet
+ * on the black market because he was tired of the wimpy water
+ * conserving toilets they make these days --Bleep
+ */
+ /*
+ * Apparently this doesn't work, the server _has_ to
+ * dump a few clients to handle the load. A fully loaded
+ * server cannot handle a net break without dumping some
+ * clients. If we flush the connections here under a full
+ * load we may end up starving the kernel for mbufs and
+ * crash the machine
+ */
+ /*
+ * attempt to recover from buffer starvation before
+ * bailing this may help servers running out of memory
+ */
+ flush_connections(0);
+ mb = msgq_alloc(0, BUFSIZE);
+ }
+ if (!mb) { /* OK, try clearing the buffer free list */
+ msgq_clear_freembs();
+ mb = msgq_alloc(0, BUFSIZE);
+ }
+ if (!mb) { /* OK, try killing a client */
+ kill_highest_sendq(0); /* Don't kill any server connections */
+ msgq_clear_freembs(); /* Release whatever was just freelisted */
+ mb = msgq_alloc(0, BUFSIZE);
+ }
+ if (!mb) { /* hmmm... */
+ kill_highest_sendq(1); /* Try killing a server connection now */
+ msgq_clear_freembs(); /* Clear freelist again */
+ mb = msgq_alloc(0, BUFSIZE);
+ }
+ if (!mb) /* AIEEEE! */
+ server_panic("Unable to allocate buffers!");
+ }
+
+ mb->next = MQData.msglist; /* initialize the msgbuf */
+ mb->prev_p = &MQData.msglist;
+
+ /* fill the buffer */
+ mb->length = ircd_vsnprintf(dest, mb->msg, bufsize(mb) - 1, format, vl);
+
+ if (mb->length > bufsize(mb) - 2)
+ mb->length = bufsize(mb) - 2;
+
+ mb->msg[mb->length++] = '\r'; /* add \r\n to buffer */
+ mb->msg[mb->length++] = '\n';
+ mb->msg[mb->length] = '\0'; /* not strictly necessary */
+
+ assert(mb->length <= bufsize(mb));
+
+ if (MQData.msglist) /* link it into the list */
+ MQData.msglist->prev_p = &mb->next;
+ MQData.msglist = mb;
+
+ return mb;
+}
+
+/** Format a message buffer for a client from a format string.
+ * @param[in] dest %Client that receives the data (may be NULL).
+ * @param[in] format Format string for message.
+ * @return Allocated MsgBuf.
+ */
+struct MsgBuf *
+msgq_make(struct Client *dest, const char *format, ...)
+{
+ va_list vl;
+ struct MsgBuf *mb;
+
+ va_start(vl, format);
+ mb = msgq_vmake(dest, format, vl);
+ va_end(vl);
+
+ return mb;
+}
+
+/** Append text to an existing message buffer.
+ * @param[in] dest %Client for whom to format the message.
+ * @param[in] mb Message buffer to append to.
+ * @param[in] format Format string of what to append.
+ */
+void
+msgq_append(struct Client *dest, struct MsgBuf *mb, const char *format, ...)
+{
+ va_list vl;
+
+ assert(0 != mb);
+ assert(0 != format);
+ assert(0 == mb->real);
+
+ assert(2 < mb->length);
+ assert(bufsize(mb) >= mb->length);
+
+ mb->length -= 2; /* back up to before \r\n */
+
+ va_start(vl, format); /* append to the buffer */
+ mb->length += ircd_vsnprintf(dest, mb->msg + mb->length,
+ bufsize(mb) - mb->length - 1, format, vl);
+ va_end(vl);
+
+ if (mb->length > bufsize(mb) - 2)
+ mb->length = bufsize(mb) - 2;
+
+ mb->msg[mb->length++] = '\r'; /* add \r\n to buffer */
+ mb->msg[mb->length++] = '\n';
+ mb->msg[mb->length] = '\0'; /* not strictly necessary */
+
+ assert(mb->length <= bufsize(mb));
+}
+
+/** Decrement the reference count on \a mb, freeing it if needed.
+ * @param[in] mb MsgBuf to release.
+ */
+void
+msgq_clean(struct MsgBuf *mb)
+{
+ assert(0 != mb);
+ assert(0 < mb->ref);
+
+ if (!--mb->ref) { /* deallocate the message */
+ if (mb->prev_p) {
+ *mb->prev_p = mb->next; /* clip it out of active MsgBuf's list */
+ if (mb->next)
+ mb->next->prev_p = mb->prev_p;
+ }
+
+ if (mb->real && mb->real != mb) /* clean up the real buffer */
+ msgq_clean(mb->real);
+
+ mb->next = MQData.msgBufs[mb->power - MB_BASE_SHIFT].free;
+ MQData.msgBufs[mb->power - MB_BASE_SHIFT].free = mb;
+ MQData.msgBufs[mb->power - MB_BASE_SHIFT].used--;
+
+ mb->prev_p = 0;
+ }
+}
+
+/** Append a message to a peer's message queue.
+ * @param[in] mq Message queue to append to.
+ * @param[in] mb Message to append.
+ * @param[in] prio If non-zero, use the high-priority (lag-busting) message list; else use the normal list.
+ */
+void
+msgq_add(struct MsgQ *mq, struct MsgBuf *mb, int prio)
+{
+ struct MsgQList *qlist;
+ struct Msg *msg;
+
+ assert(0 != mq);
+ assert(0 != mb);
+ assert(0 < mb->ref);
+ assert(0 < mb->length);
+
+ Debug((DEBUG_SEND, "Adding buffer %p [%.*s] length %u to %s queue", mb,
+ mb->length - 2, mb->msg, mb->length, prio ? "priority" : "normal"));
+
+ qlist = prio ? &mq->prio : &mq->queue;
+
+ if (!(msg = MQData.msgs.free)) { /* do I need to allocate one? */
+ msg = (struct Msg *)MyMalloc(sizeof(struct Msg));
+ MQData.msgs.alloc++; /* we allocated another */
+ } else /* shift the free list */
+ MQData.msgs.free = MQData.msgs.free->next;
+
+ MQData.msgs.used++; /* we're using another */
+
+ msg->next = 0; /* initialize the msg */
+ msg->sent = 0;
+
+ /* Get the real buffer, allocating one if necessary */
+ if (!mb->real) {
+ struct MsgBuf *tmp;
+
+ MQData.sizes.msgs++; /* update histogram counts */
+ MQData.sizes.sizes[mb->length - 1]++;
+
+ tmp = msgq_alloc(mb, mb->length); /* allocate a close-fitting buffer */
+
+ if (tmp != mb) { /* OK, prepare the new "real" buffer */
+ Debug((DEBUG_SEND, "Copying old buffer %p [%.*s] length %u into new "
+ "buffer %p size %u", mb, mb->length - 2, mb->msg, mb->length,
+ tmp, bufsize(tmp)));
+ memcpy(tmp->msg, mb->msg, mb->length + 1); /* copy string over */
+ tmp->length = mb->length;
+
+ tmp->next = mb->next; /* replace it in the list, now */
+ if (tmp->next)
+ tmp->next->prev_p = &tmp->next;
+ tmp->prev_p = mb->prev_p;
+ *tmp->prev_p = tmp;
+
+ mb->next = 0; /* this one's no longer in the list */
+ mb->prev_p = 0;
+ }
+ }
+
+ mb = mb->real; /* work with the real buffer */
+ mb->ref++; /* increment the ref count on the buffer */
+
+ msg->msg = mb; /* point at the real message buffer now */
+
+ if (!qlist->head) /* queue list was empty; head and tail point to msg */
+ qlist->head = qlist->tail = msg;
+ else {
+ assert(0 != qlist->tail);
+
+ qlist->tail->next = msg; /* queue had something in it; add to end */
+ qlist->tail = msg;
+ }
+
+ mq->length += mb->length; /* update the queue length */
+ mq->count++; /* and the queue count */
+}
+
+/** Report memory statistics for message buffers.
+ * @param[in] cptr Client requesting information.
+ * @param[out] msg_alloc Receives number of bytes allocated in Msg structs.
+ * @param[out] msgbuf_alloc Receives number of bytes allocated in MsgBuf structs.
+ */
+void
+msgq_count_memory(struct Client *cptr, size_t *msg_alloc, size_t *msgbuf_alloc)
+{
+ int i;
+ size_t total = 0, size;
+
+ assert(0 != cptr);
+ assert(0 != msg_alloc);
+ assert(0 != msgbuf_alloc);
+
+ /* Data for Msg's is simple, so just send it */
+ send_reply(cptr, SND_EXPLICIT | RPL_STATSDEBUG,
+ ":Msgs allocated %d(%zu) used %d(%zu) text %zu",
+ MQData.msgs.alloc, MQData.msgs.alloc * sizeof(struct Msg),
+ MQData.msgs.used, MQData.msgs.used * sizeof(struct Msg),
+ MQData.tot_bufsize);
+ /* count_memory() wants to know the total */
+ *msg_alloc = MQData.msgs.alloc * sizeof(struct Msg);
+
+ /* Ok, now walk through each size class */
+ for (i = MB_BASE_SHIFT; i < MB_MAX_SHIFT + 1; i++) {
+ size = sizeof(struct MsgBuf) + (1 << i); /* total size of a buffer */
+
+ /* Send information for this buffer size class */
+ send_reply(cptr, SND_EXPLICIT | RPL_STATSDEBUG,
+ ":MsgBufs of size %zu allocated %d(%zu) used %d(%zu)", 1 << i,
+ MQData.msgBufs[i - MB_BASE_SHIFT].alloc,
+ MQData.msgBufs[i - MB_BASE_SHIFT].alloc * size,
+ MQData.msgBufs[i - MB_BASE_SHIFT].used,
+ MQData.msgBufs[i - MB_BASE_SHIFT].used * size);
+
+ /* count_memory() wants to know the total */
+ total += MQData.msgBufs[i - MB_BASE_SHIFT].alloc * size;
+ }
+ *msgbuf_alloc = total;
+}
+
+/** Report remaining space in a MsgBuf.
+ * @param[in] mb Message buffer to check.
+ * @return Number of additional bytes that can be appended to the message.
+ */
+unsigned int
+msgq_bufleft(struct MsgBuf *mb)
+{
+ assert(0 != mb);
+
+ return bufsize(mb) - mb->length; /* \r\n counted in mb->length */
+}
+
+/** Send histogram of message lengths to a client.
+ * @param[in] cptr Client requesting statistics.
+ * @param[in] sd Stats descriptor for request (ignored).
+ * @param[in] param Extra parameter from user (ignored).
+ */
+void
+msgq_histogram(struct Client *cptr, const struct StatDesc *sd, char *param)
+{
+ struct MsgSizes tmp = MQData.sizes; /* All hail structure copy! */
+ int i;
+
+ send_reply(cptr, SND_EXPLICIT | RPL_STATSDEBUG,
+ ":Histogram of message lengths (%lu messages)", tmp.msgs);
+ for (i = 0; i + 16 <= BUFSIZE; i += 16)
+ send_reply(cptr, SND_EXPLICIT | RPL_STATSDEBUG, ":% 4d: %u %u %u %u "
+ "%u %u %u %u %u %u %u %u %u %u %u %u", i + 1,
+ tmp.sizes[i + 0], tmp.sizes[i + 1], tmp.sizes[i + 2],
+ tmp.sizes[i + 3], tmp.sizes[i + 4], tmp.sizes[i + 5],
+ tmp.sizes[i + 6], tmp.sizes[i + 7], tmp.sizes[i + 8],
+ tmp.sizes[i + 9], tmp.sizes[i + 10], tmp.sizes[i + 11],
+ tmp.sizes[i + 12], tmp.sizes[i + 13], tmp.sizes[i + 14],
+ tmp.sizes[i + 15]);
+}
projects / ircu2.10.12-pk.git / blobdiff