/* 
 *------------------------------------------------------------------
 * svmtool.c 
 *
 * Copyright (c) 2009 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *------------------------------------------------------------------
 */

#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <signal.h>
#include <pthread.h>
#include <unistd.h>
#include <time.h>
#include <fcntl.h>
#include <string.h>
#include <vppinfra/clib.h>
#include <vppinfra/vec.h>
#include <vppinfra/hash.h>
#include <vppinfra/bitmap.h>
#include <vppinfra/fifo.h>
#include <vppinfra/time.h>
#include <vppinfra/mheap.h>
#include <vppinfra/heap.h>
#include <vppinfra/pool.h>
#include <vppinfra/format.h>

#include "svm.h"


/*
 * format_all_svm_regions
 * Maps / unmaps regions. Do NOT call from client code!
 */
u8 *format_all_svm_regions (u8 *s, va_list * args)
{
    int verbose = va_arg (*args, int);
    svm_region_t *root_rp = svm_get_root_rp();
    svm_main_region_t *mp;
    svm_subregion_t *subp;
    svm_region_t *rp;
    svm_map_region_args_t *a = 0;
    u8 ** svm_names=0;
    u8 *name=0;
    int i;

    ASSERT(root_rp);

    pthread_mutex_lock (&root_rp->mutex);

    s = format (s, "%U", format_svm_region, root_rp, verbose);

    mp = root_rp->data_base;

    /* 
     * Snapshoot names, can't hold root rp mutex across
     * find_or_create.
     */
    pool_foreach (subp, mp->subregions, ({
	  name = vec_dup (subp->subregion_name);
	  vec_add1(svm_names, name);
	}));

    pthread_mutex_unlock (&root_rp->mutex);

    for (i = 0; i < vec_len(svm_names); i++) {
	  vec_validate(a, 0);
	  a->name = (char *) svm_names[i];
	  rp = svm_region_find_or_create (a);
	  if (rp) {
	    pthread_mutex_lock (&rp->mutex);
	    s = format (s, "%U", format_svm_region, rp, verbose);
	    pthread_mutex_unlock (&rp->mutex);
	    svm_region_unmap (rp);
            vec_free(svm_names[i]);
	  }
	  vec_free (a);
    }
    vec_free(svm_names);
    return (s);
}

void show (char *chroot_path, int verbose)
{
    svm_map_region_args_t *a = 0;

    vec_validate (a, 0);

    svm_region_init_chroot(chroot_path);

    fformat(stdout, "My pid is %d\n", getpid());

    fformat(stdout, "%U", format_all_svm_regions, verbose);

    svm_region_exit ();

    vec_free (a);
}


static void *svm_map_region_nolock (svm_map_region_args_t *a)
{
    int svm_fd;
    svm_region_t *rp;
    int deadman=0;
    u8 *shm_name;

    ASSERT((a->size & ~(MMAP_PAGESIZE-1)) == a->size);

    shm_name = shm_name_from_svm_map_region_args (a);

    svm_fd = shm_open((char *)shm_name, O_RDWR, 0777);

    if (svm_fd < 0) {
        perror("svm_region_map(mmap open)");
        return (0);
    }
    vec_free (shm_name);

    rp = mmap(0, MMAP_PAGESIZE, 
              PROT_READ | PROT_WRITE, MAP_SHARED, svm_fd, 0);
    
    if (rp == (svm_region_t *) MAP_FAILED) {
        close(svm_fd);
        clib_warning("mmap");
        return (0);
    }
    /*
     * We lost the footrace to create this region; make sure
     * the winner has crossed the finish line.
     */
    while (rp->version == 0 && deadman++ < 5) {
        sleep(1);
    }

    /*
     * <bleep>-ed? 
     */
    if (rp->version == 0) {
        clib_warning("rp->version %d not %d", rp->version,
                     SVM_VERSION);
        return (0);
    } 
    /* Remap now that the region has been placed */
    a->baseva = rp->virtual_base;
    a->size = rp->virtual_size;
    munmap(rp, MMAP_PAGESIZE);
    
    rp = (void *) mmap ((void *)a->baseva, a->size, 
                        PROT_READ | PROT_WRITE, 
                        MAP_SHARED | MAP_FIXED, svm_fd, 0);
    if ((uword)rp == (uword)MAP_FAILED) {
        clib_unix_warning ("mmap");
        return (0);
    }
    
    if ((uword) rp != rp->virtual_base) {
        clib_warning("mmap botch");
    }
    
    if (pthread_mutex_trylock(&rp->mutex)) {
        clib_warning ("rp->mutex LOCKED by pid %d, tag %d, cleared...",
                      rp->mutex_owner_pid, rp->mutex_owner_tag);
        memset(&rp->mutex, 0, sizeof (rp->mutex));
        
    } else {
        clib_warning ("mutex OK...\n");
        pthread_mutex_unlock(&rp->mutex);
    }

    return ((void *) rp);
}

/*
 * rnd_pagesize
 * Round to a pagesize multiple, presumably 4k works
 */
static unsigned int rnd_pagesize(unsigned int size)
{
    unsigned int rv;

    rv = (size + (MMAP_PAGESIZE-1)) & ~(MMAP_PAGESIZE-1);
    return(rv);
}

#define MUTEX_DEBUG

always_inline void region_lock(svm_region_t *rp, int tag)
{
    pthread_mutex_lock(&rp->mutex);
#ifdef MUTEX_DEBUG
    rp->mutex_owner_pid = getpid();
    rp->mutex_owner_tag = tag;
#endif    
}

always_inline void region_unlock(svm_region_t *rp)
{
#ifdef MUTEX_DEBUG
    rp->mutex_owner_pid = 0;
    rp->mutex_owner_tag = 0;
#endif    
    pthread_mutex_unlock(&rp->mutex);
}


static void *svm_existing_region_map_nolock (void *root_arg, 
                                             svm_map_region_args_t *a)
{
    svm_region_t *root_rp = root_arg;
    svm_main_region_t *mp;
    svm_region_t *rp;
    void *oldheap;
    uword *p;
    
    a->size +=  MMAP_PAGESIZE + SVM_PVT_MHEAP_SIZE;
    a->size = rnd_pagesize(a->size);

    region_lock (root_rp, 4);
    oldheap = svm_push_pvt_heap(root_rp);
    mp = root_rp->data_base;
    
    ASSERT(mp);

    p = hash_get_mem (mp->name_hash, a->name);

    if (p) {
        rp = svm_map_region_nolock (a);
        region_unlock(root_rp);
        svm_pop_heap (oldheap);
        return rp;
    }
    return 0;

}

static void trace (char *chroot_path, char *name, int enable_disable)
{
    svm_map_region_args_t *a = 0;
    svm_region_t *db_rp;
    void *oldheap;

    vec_validate (a, 0);

    svm_region_init_chroot(chroot_path);

    a->name = name;
    a->size = 1<<20;
    a->flags = SVM_FLAGS_MHEAP;

    db_rp = svm_region_find_or_create (a);
    
    ASSERT(db_rp);
    
    region_lock (db_rp, 20);
    
    oldheap = svm_push_data_heap (db_rp);

    mheap_trace (db_rp->data_heap, enable_disable);
    
    svm_pop_heap (oldheap);
    region_unlock (db_rp);

    svm_region_unmap ((void *)db_rp);
    svm_region_exit ();
    vec_free (a);
}


static void subregion_repair(char *chroot_path)
{
    int i;
    svm_main_region_t *mp;
    svm_map_region_args_t a;
    svm_region_t *root_rp;
    svm_region_t *rp;
    svm_subregion_t *subp;
    u8 *name=0;
    u8 ** svm_names=0;

    svm_region_init_chroot(chroot_path);
    root_rp = svm_get_root_rp();
    
    pthread_mutex_lock (&root_rp->mutex);
    
    mp = root_rp->data_base;
    
    /* 
     * Snapshoot names, can't hold root rp mutex across
     * find_or_create.
     */
    pool_foreach (subp, mp->subregions, ({
                name = vec_dup (subp->subregion_name);
                vec_add1(svm_names, name);
            }));
    
    pthread_mutex_unlock (&root_rp->mutex);
    
    for (i = 0; i < vec_len(svm_names); i++) {
        memset (&a, 0, sizeof (a));
        a.root_path = chroot_path;
        a.name = (char *) svm_names[i];
        fformat(stdout, "Checking %s region...\n",
                a.name);
        rp = svm_existing_region_map_nolock (root_rp, &a);
        if (rp) {
            svm_region_unmap (rp);
            vec_free(svm_names[i]);
        }
    }
    vec_free(svm_names);
}

void repair (char *chroot_path, int crash_root_region)
{
    svm_region_t *root_rp = 0;
    svm_map_region_args_t *a = 0;
    void *svm_map_region (svm_map_region_args_t *a);
    int svm_fd;
    u8 *shm_name;

    fformat(stdout, "our pid: %d\n", getpid());

    vec_validate (a, 0);

    a->root_path = chroot_path;
    a->name = SVM_GLOBAL_REGION_NAME;
    a->baseva = SVM_GLOBAL_REGION_BASEVA;
    a->size = SVM_GLOBAL_REGION_SIZE;
    a->flags = SVM_FLAGS_NODATA;

    shm_name = shm_name_from_svm_map_region_args (a);

    svm_fd = shm_open ((char *)shm_name, O_RDWR, 0777);

    if (svm_fd < 0) {
        perror("svm_region_map(mmap open)");
        goto out;
    }

    vec_free(shm_name);

    root_rp = mmap(0, MMAP_PAGESIZE, 
              PROT_READ | PROT_WRITE, MAP_SHARED, svm_fd, 0);
    
    if (root_rp == (svm_region_t *) MAP_FAILED) {
        close(svm_fd);
        clib_warning("mmap");
        goto out;
    }
    
    /* Remap now that the region has been placed */
    clib_warning ("remap to 0x%x", root_rp->virtual_base);

    a->baseva = root_rp->virtual_base;
    a->size = root_rp->virtual_size;
    munmap(root_rp, MMAP_PAGESIZE);
    
    root_rp = (void *) mmap ((void *)a->baseva, a->size, 
                        PROT_READ | PROT_WRITE, 
                        MAP_SHARED | MAP_FIXED, svm_fd, 0);
    if ((uword)root_rp == (uword)MAP_FAILED) {
        clib_unix_warning ("mmap");
        goto out;
    }
    
    close(svm_fd);

    if ((uword) root_rp != root_rp->virtual_base) {
        clib_warning("mmap botch");
        goto out;
    }
    
    if (pthread_mutex_trylock(&root_rp->mutex)) {
        clib_warning ("root_rp->mutex LOCKED by pid %d, tag %d, cleared...",
                      root_rp->mutex_owner_pid, root_rp->mutex_owner_tag);
        memset(&root_rp->mutex, 0, sizeof (root_rp->mutex));
        goto out;
    } else {
        clib_warning ("root_rp->mutex OK...\n");
        pthread_mutex_unlock(&root_rp->mutex);
    }
    
 out:
    vec_free (a);
    /*
     * Now that the root region is known to be OK, 
     * fix broken subregions
     */
    subregion_repair(chroot_path);

    if (crash_root_region) {
        clib_warning ("Leaving root region locked on purpose...");
        pthread_mutex_lock(&root_rp->mutex);
        root_rp->mutex_owner_pid = getpid();
        root_rp->mutex_owner_tag = 99;
    }
    svm_region_exit ();
}

int main (int argc, char **argv)
{
    unformat_input_t input;
    int parsed =0;
    char *name;
    char *chroot_path = 0;
    u8 *chroot_u8;

    unformat_init_command_line (&input, argv);

    while (unformat_check_input (&input) != UNFORMAT_END_OF_INPUT) {
        if (unformat(&input, "show-verbose")) {
            show (chroot_path, 1);
            parsed++;
        } else if (unformat (&input, "show")) {
            show (chroot_path, 0);
            parsed++;
        } else if (unformat (&input, "client-scan")) {
            svm_client_scan(chroot_path);
            parsed++;
        } else if (unformat (&input, "repair")) {
            repair(chroot_path, 0 /* fix it */);
            parsed++;
        } else if (unformat (&input, "crash")) {
            repair (chroot_path, 1 /* crash it */);
            parsed++;
        } else if (unformat (&input, "trace-on %s", &name)) {
            trace (chroot_path, name, 1);
            parsed++;
        } else if (unformat (&input, "trace-off %s", &name)) {
            trace (chroot_path, name, 0);
            parsed++;
        } else if (unformat (&input, "chroot %s", &chroot_u8)) {
            chroot_path = (char *) chroot_u8;
        } else {
            break;
        }
    }

    unformat_free (&input);

    if (!parsed) {
        fformat(stdout, "%s: show | show-verbose | client-scan | trace-on <region-name>\n", argv[0]);
        fformat(stdout, "      trace-off <region-name>\n");
    }
    exit (0);
}