[apple/xnu.git] / osfmk / kern / kmod.c

/*
 * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * Copyright (c) 1999 Apple Computer, Inc.  All rights reserved. 
 *
 * HISTORY
 *
 * 1999 Mar 29 rsulack created.
 */

#include <mach/mach_types.h>
#include <mach/vm_types.h>
#include <mach/kern_return.h>
#include <kern/kern_types.h>
#include <vm/vm_kern.h>
#include <kern/thread.h>

#include <mach_host.h>

kmod_info_t *kmod = 0;
static int kmod_index = 1;

decl_simple_lock_data(,kmod_lock)
decl_simple_lock_data(,kmod_queue_lock)

typedef struct cmd_queue_entry {
        queue_chain_t   links;
        vm_address_t    data;
        vm_size_t       size;
} cmd_queue_entry_t;

queue_head_t    kmod_cmd_queue;

void
kmod_init()
{
        simple_lock_init(&kmod_lock, ETAP_MISC_Q);
        simple_lock_init(&kmod_queue_lock, ETAP_MISC_Q);
        queue_init(&kmod_cmd_queue);
}

kmod_info_t *
kmod_lookupbyid(kmod_t id)
{
        kmod_info_t *k = 0;

        k = kmod;
        while (k) {
                if (k->id == id) break;
                k = k->next;
        }

        return k;
}

kmod_info_t *
kmod_lookupbyname(char * name)
{
        kmod_info_t *k = 0;

        k = kmod;
        while (k) {
                if (!strcmp(k->name, name)) break;
                k = k->next;
        }

        return k;
}

// XXX add a nocopy flag??

kern_return_t
kmod_queue_cmd(vm_address_t data, vm_size_t size)
{
        kern_return_t rc;
        cmd_queue_entry_t *e = (cmd_queue_entry_t *)kalloc(sizeof(struct cmd_queue_entry));
        if (!e) return KERN_RESOURCE_SHORTAGE;

        rc = kmem_alloc(kernel_map, &e->data, size);
        if (rc != KERN_SUCCESS) {
                kfree((vm_offset_t)e, sizeof(struct cmd_queue_entry));
                return rc;
        }
        e->size = size;
        bcopy((void *)data, (void *)e->data, size);

        simple_lock(&kmod_queue_lock);
        enqueue_tail(&kmod_cmd_queue, (queue_entry_t)e);
        simple_unlock(&kmod_queue_lock);

        thread_wakeup_one((event_t)&kmod_cmd_queue);
        
        return KERN_SUCCESS;
}

kern_return_t
kmod_load_extension(char *name)
{
        kmod_load_extension_cmd_t       *data;
        vm_size_t                       size;

        size = sizeof(kmod_load_extension_cmd_t);
        data = (kmod_load_extension_cmd_t *)kalloc(size);
        if (!data) return KERN_RESOURCE_SHORTAGE;

        data->type = KMOD_LOAD_EXTENSION_PACKET;
        strncpy(data->name, name, KMOD_MAX_NAME);

        return kmod_queue_cmd((vm_address_t)data, size);
}

kern_return_t
kmod_load_extension_with_dependencies(char *name, char **dependencies)
{
        kmod_load_with_dependencies_cmd_t *data;
        vm_size_t       size;
        char            **c;
        int             i, count = 0;

        c = dependencies;
        if (c) {
                while (*c) {
                        count++; c++;
                }
        }
        size = sizeof(int) + KMOD_MAX_NAME * (count + 1) + 1; 
        data = (kmod_load_with_dependencies_cmd_t *)kalloc(size);
        if (!data) return KERN_RESOURCE_SHORTAGE;

        data->type = KMOD_LOAD_WITH_DEPENDENCIES_PACKET;
        strncpy(data->name, name, KMOD_MAX_NAME);

        c = dependencies;
        for (i=0; i < count; i++) {
                strncpy(data->dependencies[i], *c, KMOD_MAX_NAME);
                c++;
        }
        data->dependencies[count][0] = 0;

        return kmod_queue_cmd((vm_address_t)data, size);
}
kern_return_t
kmod_send_generic(int type, void *generic_data, int size)
{
        kmod_generic_cmd_t      *data;

        data = (kmod_generic_cmd_t *)kalloc(size + sizeof(int));
        if (!data) return KERN_RESOURCE_SHORTAGE;

        data->type = type;
        bcopy(data->data, generic_data, size);

        return kmod_queue_cmd((vm_address_t)data, size + sizeof(int));
}

kern_return_t
kmod_create_internal(kmod_info_t *info, kmod_t *id)
{
        kern_return_t rc;

        if (!info) return KERN_INVALID_ADDRESS;

        // double check for page alignment
        if ((info->address | info->hdr_size) & (PAGE_SIZE - 1)) {
                return KERN_INVALID_ADDRESS;
        }

        rc = vm_map_wire(kernel_map, info->address + info->hdr_size, 
                         info->address + info->size, VM_PROT_DEFAULT, FALSE);
        if (rc != KERN_SUCCESS) {
                return rc;
        }

        simple_lock(&kmod_lock);

        // check to see if already loaded
        if (kmod_lookupbyname(info->name)) {
                simple_unlock(&kmod_lock);
                rc = vm_map_unwire(kernel_map, info->address + info->hdr_size, 
                                   info->address + info->size, FALSE);
                assert(rc == KERN_SUCCESS);
                return KERN_INVALID_ARGUMENT;
        }

        info->id = kmod_index++;
        info->reference_count = 0;

        info->next = kmod;
        kmod = info;

        *id = info->id;

        simple_unlock(&kmod_lock);

        printf("kmod_create: %s (id %d), %d pages loaded at 0x%x, header size 0x%x\n", 
               info->name, info->id, info->size / PAGE_SIZE, info->address, info->hdr_size);

        return KERN_SUCCESS;
}


kern_return_t
kmod_create(host_priv_t host_priv,
            kmod_info_t *info,
            kmod_t *id)
{
        if (host_priv == HOST_PRIV_NULL) return KERN_INVALID_HOST;
        return kmod_create_internal(info, id);
}

kern_return_t
kmod_create_fake(char *name, char *version)
{
        kmod_info_t *info;

        info = (kmod_info_t *)kalloc(sizeof(kmod_info_t));
        if (!info) {
                return KERN_RESOURCE_SHORTAGE;
        }

        // make de fake
        info->info_version = KMOD_INFO_VERSION;
        bcopy(name, info->name, KMOD_MAX_NAME);
        bcopy(version, info->version, KMOD_MAX_NAME);
        info->reference_count = 1;      // keep it from unloading, starting, stopping
        info->reference_list = 0;
        info->address = info->size = info->hdr_size = 0;
        info->start = info->stop = 0;

        simple_lock(&kmod_lock);

        // check to see if already "loaded"
        if (kmod_lookupbyname(info->name)) {
                simple_unlock(&kmod_lock);
                return KERN_INVALID_ARGUMENT;
        }

        info->id = kmod_index++;

        info->next = kmod;
        kmod = info;

        simple_unlock(&kmod_lock);

        return KERN_SUCCESS;
}

kern_return_t
kmod_destroy_internal(kmod_t id)
{
        kern_return_t rc;
        kmod_info_t *k;
        kmod_info_t *p;

        simple_lock(&kmod_lock);

        k = p = kmod;
        while (k) {
                if (k->id == id) {
                        kmod_reference_t *r, *t;

                        if (k->reference_count != 0) {
                                simple_unlock(&kmod_lock);
                                return KERN_INVALID_ARGUMENT;
                        }
                                
                        if (k == p) {   // first element
                                kmod = k->next;
                        } else {
                                p->next = k->next;
                        }
                        simple_unlock(&kmod_lock);

                        r = k->reference_list;
                        while (r) {
                                r->info->reference_count--;
                                t = r;
                                r = r->next;
                                kfree((vm_offset_t)t, sizeof(struct kmod_reference));
                        }

                        printf("kmod_destroy: %s (id %d), deallocating %d pages starting at 0x%x\n", 
                               k->name, k->id, k->size / PAGE_SIZE, k->address);

                        rc = vm_map_unwire(kernel_map, k->address + k->hdr_size, 
                                           k->address + k->size, FALSE);
                        assert(rc == KERN_SUCCESS);

                        rc = vm_deallocate(kernel_map, k->address, k->size);
                        assert(rc == KERN_SUCCESS);

                        return KERN_SUCCESS;
                }
                p = k;
                k = k->next;
        }

        simple_unlock(&kmod_lock);

        return KERN_INVALID_ARGUMENT;
}


kern_return_t
kmod_destroy(host_priv_t host_priv,
             kmod_t id)
{
        if (host_priv == HOST_PRIV_NULL) return KERN_INVALID_HOST;
        return kmod_destroy_internal(id);
}


kern_return_t
kmod_start_or_stop(
    kmod_t id,
    int start,
    kmod_args_t *data,
    mach_msg_type_number_t *dataCount)
{
    kern_return_t rc = KERN_SUCCESS;
    void * user_data = 0;
    kern_return_t (*func)();
    kmod_info_t *k;

    simple_lock(&kmod_lock);

    k = kmod_lookupbyid(id);
    if (!k || k->reference_count) {
        simple_unlock(&kmod_lock);
        rc = KERN_INVALID_ARGUMENT;
        goto finish;
    }

    if (start) {
        func = (void *)k->start;
    } else {
        func = (void *)k->stop;
    }

    simple_unlock(&kmod_lock);

    //
    // call kmod entry point
    //
    if (data && dataCount && *data && *dataCount) {
        vm_map_copyout(kernel_map, (vm_offset_t *)&user_data, (vm_map_copy_t)*data);
    }

    rc = (*func)(k, user_data);

finish:

    if (user_data) {
        (void) vm_deallocate(kernel_map, (vm_offset_t)user_data, *dataCount);
    }
    if (data) *data = 0;
    if (dataCount) *dataCount = 0;

    return rc;
}


/*
 * The retain and release calls take no user data, but the caller
 * may have sent some in error (the MIG definition allows it).
 * If this is the case, they will just return that same data
 * right back to the caller (since they never touch the *data and
 * *dataCount fields).
 */
kern_return_t
kmod_retain(kmod_t id)
{
    kern_return_t rc = KERN_SUCCESS;

    kmod_info_t *t;    // reference to
    kmod_info_t *f;    // reference from
    kmod_reference_t *r = 0;

    r = (kmod_reference_t *)kalloc(sizeof(struct kmod_reference));
    if (!r) {
        rc = KERN_RESOURCE_SHORTAGE;
        goto finish;
    }

    simple_lock(&kmod_lock);

    t = kmod_lookupbyid(KMOD_UNPACK_TO_ID(id));
    f = kmod_lookupbyid(KMOD_UNPACK_FROM_ID(id));
    if (!t || !f) {
        simple_unlock(&kmod_lock);
        if (r) kfree((vm_offset_t)r, sizeof(struct kmod_reference));
        rc = KERN_INVALID_ARGUMENT;
        goto finish;
    }

    r->next = f->reference_list;
    r->info = t;
    f->reference_list = r;
    t->reference_count++;

    simple_unlock(&kmod_lock);

finish:

    return rc;
}


kern_return_t
kmod_release(kmod_t id)
{
    kern_return_t rc = KERN_INVALID_ARGUMENT;

    kmod_info_t *t;    // reference to
    kmod_info_t *f;    // reference from
    kmod_reference_t *r = 0;
    kmod_reference_t * p;

    simple_lock(&kmod_lock);

    t = kmod_lookupbyid(KMOD_UNPACK_TO_ID(id));
    f = kmod_lookupbyid(KMOD_UNPACK_FROM_ID(id));
    if (!t || !f) {
        rc = KERN_INVALID_ARGUMENT;
        goto finish;
    }

    p = r = f->reference_list;
    while (r) {
        if (r->info == t) {
            if (p == r) {       // first element
                f->reference_list = r->next;
            } else {
                p->next = r->next;
            }
            r->info->reference_count--;

            simple_unlock(&kmod_lock);
            kfree((vm_offset_t)r, sizeof(struct kmod_reference));
            rc = KERN_SUCCESS;
            goto finish;
        }
        p = r;
        r = r->next;
    }

    simple_unlock(&kmod_lock);

finish:

    return rc;
}


kern_return_t
kmod_control(host_priv_t host_priv,
             kmod_t id,
             kmod_control_flavor_t flavor,
             kmod_args_t *data,
             mach_msg_type_number_t *dataCount)
{
        kern_return_t rc = KERN_SUCCESS;

        if (host_priv == HOST_PRIV_NULL) return KERN_INVALID_HOST;

        switch (flavor) {

        case KMOD_CNTL_START:
        case KMOD_CNTL_STOP: 
        {
            rc = kmod_start_or_stop(id, (flavor == KMOD_CNTL_START),
                data, dataCount);
            break;
        }

        case KMOD_CNTL_RETAIN:
        {
            rc = kmod_retain(id);
            break;
        }

        case KMOD_CNTL_RELEASE:
        {
            rc = kmod_release(id);
            break;
        }

        case KMOD_CNTL_GET_CMD: {

                cmd_queue_entry_t *e;

                /*
                 * Throw away any data the user may have sent in error.
                 * We must do this, because we are likely to return to
                 * some data for these commands (thus causing a leak of
                 * whatever data the user sent us in error).
                 */
                if (*data && *dataCount) {
                        vm_map_copy_discard(*data);
                        *data = 0;
                        *dataCount = 0;
                }
                        
                simple_lock(&kmod_queue_lock);

                if (queue_empty(&kmod_cmd_queue)) {
                        assert_wait((event_t)&kmod_cmd_queue, THREAD_ABORTSAFE);
                        simple_unlock(&kmod_queue_lock);
                        thread_block((void(*)(void))0);
                        simple_lock(&kmod_queue_lock);
                        if (queue_empty(&kmod_cmd_queue)) {
                                // we must have been interrupted!
                                simple_unlock(&kmod_queue_lock);
                                return KERN_ABORTED;
                        }
                }
                e = (cmd_queue_entry_t *)dequeue_head(&kmod_cmd_queue);

                simple_unlock(&kmod_queue_lock);

                rc = vm_map_copyin(kernel_map, e->data, e->size, TRUE, (vm_map_copy_t *)data);
                if (rc) {
                        simple_lock(&kmod_queue_lock);
                        enqueue_head(&kmod_cmd_queue, (queue_entry_t)e);
                        simple_unlock(&kmod_queue_lock);
                        *data = 0;
                        *dataCount = 0;
                        return rc;
                }
                *dataCount = e->size;

                kfree((vm_offset_t)e, sizeof(struct cmd_queue_entry));
                
                break;
        }

        default:
                rc = KERN_INVALID_ARGUMENT;
        }

        return rc;
};


kern_return_t
kmod_get_info(host_t host,
              kmod_info_array_t *kmods,
              mach_msg_type_number_t *kmodCount)
{
        vm_offset_t data;
        kmod_info_t *k, *p1;
        kmod_reference_t *r, *p2;
        int ref_count;
        unsigned size = 0;
        kern_return_t rc = KERN_SUCCESS;

        *kmods = (void *)0;
        *kmodCount = 0;

retry:
        simple_lock(&kmod_lock);
        size = 0;
        k = kmod;
        while (k) {
                size += sizeof(kmod_info_t);
                r = k->reference_list;
                while (r) {
                        size +=sizeof(kmod_reference_t);
                        r = r->next;
                }
                k = k->next;
        }
        simple_unlock(&kmod_lock);
        if (!size) return KERN_SUCCESS;

        rc = kmem_alloc(kernel_map, &data, size);
        if (rc) return rc;

        // copy kmod into data, retry if kmod's size has changed (grown)
        // the copied out data is tweeked to figure what's what at user level
        // change the copied out k->next pointers to point to themselves
        // change the k->reference into a count, tack the references on
        // the end of the data packet in the order they are found

        simple_lock(&kmod_lock);
        k = kmod; p1 = (kmod_info_t *)data;
        while (k) {
                if ((p1 + 1) > (kmod_info_t *)(data + size)) {
                        simple_unlock(&kmod_lock);
                        kmem_free(kernel_map, data, size);
                        goto retry;
                }

                *p1 = *k;
                if (k->next) p1->next = k;
                p1++; k = k->next;
        }

        p2 = (kmod_reference_t *)p1;
        k = kmod; p1 = (kmod_info_t *)data;
        while (k) {
                r = k->reference_list; ref_count = 0;
                while (r) {
                        if ((p2 + 1) > (kmod_reference_t *)(data + size)) {
                                simple_unlock(&kmod_lock);
                                kmem_free(kernel_map, data, size);
                                goto retry;
                        }
                        // note the last 'k' in the chain has its next == 0
                        // since there can only be one like that, 
                        // this case is handled by the caller
                        *p2 = *r;
                        p2++; r = r->next; ref_count++;
                }
                p1->reference_list = (kmod_reference_t *)ref_count;
                p1++; k = k->next;
        }
        simple_unlock(&kmod_lock);
        
        rc = vm_map_copyin(kernel_map, data, size, TRUE, (vm_map_copy_t *)kmods);
        if (rc) {
                kmem_free(kernel_map, data, size);
                *kmods = 0;
                *kmodCount = 0;
                return rc;
        }
        *kmodCount = size;

        return KERN_SUCCESS;
}

#include <mach-o/loader.h>

extern void *getsectdatafromheader(struct mach_header *mhp,
                                   const char *segname,
                                   const char *sectname,
                                   int *size);

static kern_return_t
kmod_call_funcs_in_section(struct mach_header *header, const char *sectName)
{
        typedef void    (*Routine)(void);
        Routine *       routines;
        int             size, i;

        if (header->magic != MH_MAGIC) {
                return KERN_INVALID_ARGUMENT;
        }

        routines = (Routine *) getsectdatafromheader(header, SEG_TEXT, sectName, &size);
        if (!routines) return KERN_SUCCESS;

        size /= sizeof(Routine);
        for (i = 0; i < size; i++) {
                (*routines[i])();
        }

        return KERN_SUCCESS;
}

kern_return_t
kmod_initialize_cpp(kmod_info_t *info)
{
        return kmod_call_funcs_in_section((struct mach_header *)info->address, "__constructor");
}

kern_return_t
kmod_finalize_cpp(kmod_info_t *info)
{
        return kmod_call_funcs_in_section((struct mach_header *)info->address, "__destructor");
}

kern_return_t
kmod_default_start(struct kmod_info *ki, void *data)
{
        return KMOD_RETURN_SUCCESS;
}

kern_return_t
kmod_default_stop(struct kmod_info *ki, void *data)
{
        return KMOD_RETURN_SUCCESS;
}

#define IS_IN_BACKTRACE 0xdeadbeef
#define IS_A_DEPENDENCY 0xbeefdead

void
kmod_dump(vm_offset_t *addr, unsigned int cnt)
{
    kmod_info_t *k;
    kmod_reference_t *r;
    int i, found_one = 0;

    // find backtrace addresses that are inside a kmod
    for (i=0; i < cnt; i++, addr++) {
        k = kmod;
        while (k) {
            // XXX - validate page(s) that k points to
                if(pmap_extract(kernel_pmap, (vm_offset_t)k) == 0) {    /* Exit loop if page not mapped */
                        printf("kmod scan stopped due to missing page: %08X\n", k);
                        break;
                }
            if ((*addr >= k->address) && (*addr < (k->address + k->size))) {
                // got one, blast info_version, we don't need it at this point
                k->info_version = IS_IN_BACKTRACE;
                found_one++;
                break;
            }
            k = k->next;
        }
    }
    if (!found_one) return;

    printf("kernel modules in backtrace: ");
    k = kmod;
    while (k) {
                if(pmap_extract(kernel_pmap, (vm_offset_t)k) == 0) {    /* Exit loop if page not mapped */
                        printf("kmod scan stopped due to missing page: %08X\n", k);
                        break;
                }
                if (k->info_version == IS_IN_BACKTRACE) {
                    printf("%s(%s)@0x%x ", k->name, k->version, k->address);
                }
                k = k->next;
    }
    printf("\n");

    // look for dependencies
    k = kmod; found_one = 0;
    while (k) {
                if(pmap_extract(kernel_pmap, (vm_offset_t)k) == 0) {    /* Exit loop if page not mapped */
                        printf("kmod dependency scan stopped due to missing page: %08X\n", k);
                        break;
                }
                if (k->info_version == IS_IN_BACKTRACE) {
                    r = k->reference_list;
                    while (r) {
                                // XXX - validate page(s) that r and r->info point to
                                if(pmap_extract(kernel_pmap, (vm_offset_t)r) == 0) {    /* Exit loop if page not mapped */
                                        printf("kmod validation scan stopped due to missing page: %08X\n", r);
                                        break;
                                }
                                if (r->info->info_version != IS_IN_BACKTRACE) {
                                    r->info->info_version = IS_A_DEPENDENCY;
                                    found_one++;
                                }
                                r = r->next;
                    }
                }
                k = k->next;
    }
    if (!found_one) goto cleanup;

    printf("kernel module dependencies: ");
    k = kmod;
    while (k) {
                if(pmap_extract(kernel_pmap, (vm_offset_t)k) == 0) {    /* Exit loop if page not mapped */
                        printf("kmod dependency print stopped due to missing page: %08X\n", k);
                        break;
                }
                if (k->info_version == IS_A_DEPENDENCY) {
                    printf("%s(%s)@0x%x ", k->name, k->version, k->address);
                }
                k = k->next;
    }
    printf("\n");

 cleanup:
    // in case we double panic
    k = kmod;
    while (k) {
                if(pmap_extract(kernel_pmap, (vm_offset_t)k) == 0) {    /* Exit loop if page not mapped */
                        printf("kmod dump cleanup stopped due to missing page: %08X\n", k);
                        break;
                }
                k->info_version = KMOD_INFO_VERSION;
                k = k->next;
    }
}