sendmail/libmilter/monitor.c

058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck/*
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck *  Copyright (c) 2006 Sendmail, Inc. and its suppliers.
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck *  All rights reserved.
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck *
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck * By using this file, you agree to the terms and conditions set
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck * forth in the LICENSE file which can be found at the top level of
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck * the sendmail distribution.
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck *
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck#pragma ident   "%Z%%M% %I% %E% SMI"
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
7800901e60d340b6af88e94a2149805dcfcaaf56jbeck#include <sm/gen.h>
7800901e60d340b6af88e94a2149805dcfcaaf56jbeckSM_RCSID("@(#)$Id: monitor.c,v 8.7 2007/04/23 16:26:28 ca Exp $")
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck#include "libmilter.h"
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck#if _FFR_THREAD_MONITOR
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck/*
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  Thread Monitoring
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  Todo: more error checking (return code from function calls)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  add comments.
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck*/
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeckbool Monitor = false; /* use monitoring? */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeckstatic unsigned int Mon_exec_time = 0;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck/* mutex protects Mon_cur_ctx, Mon_ctx_head, and ctx_start */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeckstatic smutex_t Mon_mutex;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeckstatic scond_t Mon_cv;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck/*
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  Current ctx to monitor.
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  Invariant:
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  Mon_cur_ctx == NULL || Mon_cur_ctx is thread which was started the longest
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  time ago.
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  Basically the entries in the list are ordered by time because new
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  entries are appended at the end. However, due to the concurrent
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  execution (multi-threaded) and no guaranteed order of wakeups
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  after a mutex_lock() attempt, the order might not be strict,
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  i.e., if the list contains e1 and e2 (in that order) then
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  the the start time of e2 can be (slightly) smaller than that of e1.
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  However, this slight inaccurracy should not matter for the proper
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  working of this algorithm.
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck*/
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeckstatic SMFICTX_PTR Mon_cur_ctx = NULL;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeckstatic smfi_hd_T Mon_ctx_head; /* head of the linked list of active contexts */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck/*
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  SMFI_SET_MAX_EXEC_TIME -- set maximum execution time for a thread
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  Parameters:
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**      tm -- maximum execution time for a thread
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  Returns:
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**      MI_SUCCESS
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck*/
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeckint
058561cbaa119a6f2659bc27ef343e1b47266bb2jbecksmfi_set_max_exec_time(tm)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    unsigned int tm;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck{
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    Mon_exec_time = tm;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    return MI_SUCCESS;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck}
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck/*
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  MI_MONITOR_THREAD -- monitoring thread
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  Parameters:
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**      arg -- ignored (required by pthread_create())
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  Returns:
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**      NULL on termination.
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck*/
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeckstatic void *
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeckmi_monitor_thread(arg)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    void *arg;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck{
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    sthread_t tid;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    int r;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    time_t now, end;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    SM_ASSERT(Monitor);
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    SM_ASSERT(Mon_exec_time > 0);
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    tid = (sthread_t) sthread_get_id();
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    if (pthread_detach(tid) != 0)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    {
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck        /* log an error */
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck        return (void *)1;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    }
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck/*
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  NOTE: this is "flow through" code,
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  do NOT use do { } while ("break" is used here!)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck*/
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck#define MON_CHK_STOP                            \
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    now = time(NULL);                       \
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    end = Mon_cur_ctx->ctx_start + Mon_exec_time;           \
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    if (now > end)                          \
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    {                               \
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck        smi_log(SMI_LOG_ERR,                    \
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck            "WARNING: monitor timeout triggered, now=%ld, end=%ld, tid=%ld, state=0x%x",\
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck            (long) now, (long) end,             \
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck            (long) Mon_cur_ctx->ctx_id, Mon_cur_ctx->ctx_state);\
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck        mi_stop_milters(MILTER_STOP);               \
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck        break;                          \
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    }
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    (void) smutex_lock(&Mon_mutex);
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    while (mi_stop() == MILTER_CONT)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    {
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck        if (Mon_cur_ctx != NULL && Mon_cur_ctx->ctx_start > 0)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck        {
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck            struct timespec abstime;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck            MON_CHK_STOP;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck            abstime.tv_sec = end;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck            abstime.tv_nsec = 0;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck            r = pthread_cond_timedwait(&Mon_cv, &Mon_mutex,
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck                    &abstime);
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck        }
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck        else
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck            r = pthread_cond_wait(&Mon_cv, &Mon_mutex);
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck        if (mi_stop() != MILTER_CONT)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck            break;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck        if (Mon_cur_ctx != NULL && Mon_cur_ctx->ctx_start > 0)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck        {
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck            MON_CHK_STOP;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck        }
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    }
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    (void) smutex_unlock(&Mon_mutex);
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    return NULL;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck}
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck/*
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  MI_MONITOR_INIT -- initialize monitoring thread
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  Parameters: none
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  Returns:
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**      MI_SUCCESS/MI_FAILURE
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck*/
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeckint
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeckmi_monitor_init()
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck{
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    int r;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    sthread_t tid;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    SM_ASSERT(!Monitor);
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    if (Mon_exec_time <= 0)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck        return MI_SUCCESS;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    Monitor = true;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    if (!smutex_init(&Mon_mutex))
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck        return MI_FAILURE;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    if (scond_init(&Mon_cv) != 0)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck        return MI_FAILURE;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    SM_TAILQ_INIT(&Mon_ctx_head);
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    r = thread_create(&tid, mi_monitor_thread, (void *)NULL);
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    if (r != 0)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck        return r;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    return MI_SUCCESS;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck}
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck/*
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  MI_MONITOR_WORK_BEGIN -- record start of thread execution
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  Parameters:
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**      ctx -- session context
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**      cmd -- milter command char
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  Returns:
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**      0
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck*/
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeckint
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeckmi_monitor_work_begin(ctx, cmd)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    SMFICTX_PTR ctx;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    int cmd;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck{
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    (void) smutex_lock(&Mon_mutex);
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    if (NULL == Mon_cur_ctx)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    {
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck        Mon_cur_ctx = ctx;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck        (void) scond_signal(&Mon_cv);
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    }
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    ctx->ctx_start = time(NULL);
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    SM_TAILQ_INSERT_TAIL(&Mon_ctx_head, ctx, ctx_mon_link);
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    (void) smutex_unlock(&Mon_mutex);
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    return 0;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck}
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck/*
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  MI_MONITOR_WORK_END -- record end of thread execution
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  Parameters:
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**      ctx -- session context
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**      cmd -- milter command char
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**  Returns:
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck**      0
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck*/
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeckint
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeckmi_monitor_work_end(ctx, cmd)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    SMFICTX_PTR ctx;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    int cmd;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck{
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    (void) smutex_lock(&Mon_mutex);
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    ctx->ctx_start = 0;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    SM_TAILQ_REMOVE(&Mon_ctx_head, ctx, ctx_mon_link);
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    if (Mon_cur_ctx == ctx)
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    {
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck        if (SM_TAILQ_EMPTY(&Mon_ctx_head))
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck            Mon_cur_ctx = NULL;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck        else
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck            Mon_cur_ctx = SM_TAILQ_FIRST(&Mon_ctx_head);
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    }
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    (void) smutex_unlock(&Mon_mutex);
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck    return 0;
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck}
058561cbaa119a6f2659bc27ef343e1b47266bb2jbeck#endif /* _FFR_THREAD_MONITOR */