plugins/quota/quota.c

	quota.c revision 91dca97b367c54a139c268b56a0c67f564bd9197
/* Copyright (C) 2005 Timo Sirainen */

#include "lib.h"
#include "array.h"
#include "hash.h"
#include "quota-private.h"
#include "quota-fs.h"
#include <stdlib.h>

#define RULE_NAME_ALL_MAILBOXES "*"

struct quota_root_iter {
    struct quota *quota;
    struct mailbox *box;

    unsigned int i;
};

unsigned int quota_module_id = 0;

extern struct quota_backend quota_backend_dict;
extern struct quota_backend quota_backend_dirsize;
extern struct quota_backend quota_backend_fs;
extern struct quota_backend quota_backend_maildir;

static const struct quota_backend *quota_backends[] = {
#ifdef HAVE_FS_QUOTA
    &quota_backend_fs,
#endif
    &quota_backend_dict,
    &quota_backend_dirsize,
    &quota_backend_maildir
};
#define QUOTA_CLASS_COUNT (sizeof(quota_backends)/sizeof(quota_backends[0]))

static int quota_default_test_alloc(struct quota_transaction_context *ctx,
                    uoff_t size, bool *too_large_r);

struct quota *quota_init(void)
{
    struct quota *quota;

    quota = i_new(struct quota, 1);
    quota->test_alloc = quota_default_test_alloc;
    i_array_init(&quota->roots, 4);
    i_array_init(&quota->storages, 8);

    return quota;
}

void quota_deinit(struct quota *quota)
{
    struct quota_root **root;

    while (array_count(&quota->roots) > 0) {
        root = array_idx_modifiable(&quota->roots, 0);
        quota_root_deinit(*root);
    }

    array_free(&quota->roots);
    array_free(&quota->storages);
    i_free(quota);
}

static const struct quota_backend *quota_backend_find(const char *name)
{
    unsigned int i;

    for (i = 0; i < QUOTA_CLASS_COUNT; i++) {
        if (strcmp(quota_backends[i]->name, name) == 0)
            return quota_backends[i];
    }

    return NULL;
}

struct quota_root *quota_root_init(struct quota *quota, const char *root_def)
{
    struct quota_root *root;
    const struct quota_backend *backend;
    const char *p, *args, *backend_name;

    t_push();

    /* <backend>[:<quota root name>[:<backend args>]] */
    p = strchr(root_def, ':');
    if (p == NULL) {
        backend_name = root_def;
        args = NULL;
    } else {
        backend_name = t_strdup_until(root_def, p);
        args = p + 1;
    }

    backend = quota_backend_find(backend_name);
    if (backend == NULL)
        i_fatal("Unknown quota backend: %s", backend_name);

    t_pop();

    root = backend->v.alloc();
    root->quota = quota;
    root->backend = *backend;
    root->pool = pool_alloconly_create("quota root", 512);

    if (args != NULL) {
        /* save root's name */
        p = strchr(args, ':');
        if (p == NULL) {
            root->name = p_strdup(root->pool, args);
            args = NULL;
        } else {
            root->name = p_strdup_until(root->pool, args, p);
            args = p + 1;
        }
    } else {
        root->name = "";
    }

    i_array_init(&root->rules, 4);
    array_create(&root->quota_module_contexts, default_pool,
             sizeof(void *), 5);

    array_append(&quota->roots, &root, 1);

    if (backend->v.init != NULL) {
        if (backend->v.init(root, args) < 0) {
            quota_root_deinit(root);
            return NULL;
        }
    }
    return root;
}

void quota_root_deinit(struct quota_root *root)
{
    pool_t pool = root->pool;
    struct quota_root *const *roots;
    unsigned int i, count;

    roots = array_get(&root->quota->roots, &count);
    for (i = 0; i < count; i++) {
        if (roots[i] == root)
            array_delete(&root->quota->roots, i, 1);
    }

    array_free(&root->rules);
    array_free(&root->quota_module_contexts);

    root->backend.v.deinit(root);
    pool_unref(pool);
}

static struct quota_rule *
quota_root_rule_find(struct quota_root *root, const char *name)
{
    struct quota_rule *rules;
    unsigned int i, count;

    rules = array_get_modifiable(&root->rules, &count);
    for (i = 0; i < count; i++) {
        if (strcmp(rules[i].mailbox_name, name) == 0)
            return &rules[i];
    }
    return NULL;
}

int quota_root_add_rule(struct quota_root *root, const char *rule_def,
            const char **error_r)
{
    struct quota_rule *rule;
    const char **args;
    int ret = 0;

    if (*rule_def == '\0') {
        *error_r = "Empty rule";
        return -1;
    }

    /* <mailbox name>:<quota limits> */
    t_push();
        args = t_strsplit(rule_def, ":");

    rule = quota_root_rule_find(root, *args);
    if (rule == NULL) {
        if (strcmp(*args, RULE_NAME_ALL_MAILBOXES) == 0)
            rule = &root->default_rule;
        else {
            rule = array_append_space(&root->rules);
            rule->mailbox_name = p_strdup(root->pool, *args);
        }
    }

    for (args++; *args != NULL; args++) {
        if (strncmp(*args, "storage=", 8) == 0)
            rule->bytes_limit = strtoll(*args + 8, NULL, 10) * 1024;
        else if (strncmp(*args, "messages=", 9) == 0)
            rule->count_limit = strtoll(*args + 9, NULL, 10);
        else {
            *error_r = p_strdup_printf(root->pool,
                    "Invalid rule limit: %s", *args);
            ret = -1;
            break;
        }
    }
    t_pop();
    return ret;
}

static bool quota_root_get_rule_limits(struct quota_root *root,
                       const char *mailbox_name,
                       uint64_t *bytes_limit_r,
                       uint64_t *count_limit_r)
{
    struct quota_rule *rule;
    int64_t bytes_limit, count_limit;
    bool found;

    bytes_limit = root->default_rule.bytes_limit;
    count_limit = root->default_rule.count_limit;

    /* if default rule limits are 0, this rule applies only to specific
       mailboxes */
    found = bytes_limit != 0 || count_limit != 0;

    rule = quota_root_rule_find(root, mailbox_name);
    if (rule != NULL) {
        bytes_limit += rule->bytes_limit;
        count_limit += rule->count_limit;
        found = TRUE;
    }

    *bytes_limit_r = bytes_limit <= 0 ? 0 : bytes_limit;
    *count_limit_r = count_limit <= 0 ? 0 : count_limit;
    return found;
}

void quota_add_user_storage(struct quota *quota, struct mail_storage *storage)
{
    struct quota_root *const *roots;
    struct quota_backend **backends;
    unsigned int i, j, count;

    array_append(&quota->storages, &storage, 1);

    roots = array_get(&quota->roots, &count);
    /* @UNSAFE: get different backends into one array */
    backends = t_new(struct quota_backend *, count + 1);
    for (i = 0; i < count; i++) {
        for (j = 0; backends[j] != NULL; j++) {
            if (backends[j]->name == roots[i]->backend.name)
                break;
        }
        if (backends[j] == NULL)
            backends[j] = &roots[i]->backend;
    }

    for (i = 0; backends[i] != NULL; i++) {
        if (backends[i]->v.storage_added != NULL)
            backends[i]->v.storage_added(quota, storage);
    }
}

void quota_remove_user_storage(struct quota *quota,
                   struct mail_storage *storage)
{
    struct mail_storage *const *storages;
    unsigned int i, count;

    storages = array_get(&quota->storages, &count);
    for (i = 0; i < count; i++) {
        if (storages[i] == storage) {
            array_delete(&quota->storages, i, 1);
            break;
        }
    }
}

struct quota_root_iter *
quota_root_iter_init(struct quota *quota, struct mailbox *box)
{
    struct quota_root_iter *iter;

    iter = i_new(struct quota_root_iter, 1);
    iter->quota = quota;
    iter->box = box;
    return iter;
}

struct quota_root *quota_root_iter_next(struct quota_root_iter *iter)
{
    struct quota_root *const *roots, *root = NULL;
    unsigned int count;
    uint64_t value, limit;
    int ret;

    roots = array_get(&iter->quota->roots, &count);
    if (iter->i >= count)
        return NULL;

    for (; iter->i < count; iter->i++) {
        ret = quota_get_resource(roots[iter->i], "",
                     QUOTA_NAME_STORAGE, &value, &limit);
        if (ret == 0) {
            ret = quota_get_resource(roots[iter->i], "",
                         QUOTA_NAME_MESSAGES,
                         &value, &limit);
        }
        if (ret > 0) {
            root = roots[iter->i];
            break;
        }
    }

    iter->i++;
    return root;
}

void quota_root_iter_deinit(struct quota_root_iter *iter)
{
    i_free(iter);
}

struct quota_root *quota_root_lookup(struct quota *quota, const char *name)
{
    struct quota_root *const *roots;
    unsigned int i, count;

    roots = array_get(&quota->roots, &count);
    for (i = 0; i < count; i++) {
        if (strcmp(roots[i]->name, name) == 0)
            return roots[i];
    }
    return NULL;
}

const char *quota_root_get_name(struct quota_root *root)
{
    return root->name;
}

const char *const *quota_root_get_resources(struct quota_root *root)
{
    return root->backend.v.get_resources(root);
}

int quota_get_resource(struct quota_root *root, const char *mailbox_name,
               const char *name, uint64_t *value_r, uint64_t *limit_r)
{
    uint64_t bytes_limit, count_limit;
    int ret;

    (void)quota_root_get_rule_limits(root, mailbox_name,
                     &bytes_limit, &count_limit);
    if (strcmp(name, QUOTA_NAME_STORAGE) == 0)
        *limit_r = bytes_limit;
    else if (strcmp(name, QUOTA_NAME_MESSAGES) == 0)
        *limit_r = count_limit;
    else
        *limit_r = 0;

    ret = root->backend.v.get_resource(root, name, value_r, limit_r);
    return ret <= 0 ? ret :
        (*limit_r == 0 ? 0 : 1);
}

int quota_set_resource(struct quota_root *root __attr_unused__,
               const char *name __attr_unused__,
               uint64_t value __attr_unused__, const char **error_r)
{
    /* the quota information comes from userdb (or even config file),
       so there's really no way to support this until some major changes
       are done */
    *error_r = MAIL_STORAGE_ERR_NO_PERMISSION;
    return -1;
}

struct quota_transaction_context *quota_transaction_begin(struct quota *quota,
                              struct mailbox *box)
{
    struct quota_transaction_context *ctx;
    struct quota_root *const *roots;
    const char *mailbox_name;
    unsigned int i, count;
    uint64_t current, limit, left;
    int ret;

    mailbox_name = mailbox_get_name(box);

    ctx = i_new(struct quota_transaction_context, 1);
    ctx->quota = quota;
    ctx->box = box;
    ctx->bytes_left = (uint64_t)-1;
    ctx->count_left = (uint64_t) -1;

    /* find the lowest quota limits from all roots and use them */
    roots = array_get(&quota->roots, &count);
    for (i = 0; i < count; i++) {
        ret = quota_get_resource(roots[i], mailbox_name,
                     QUOTA_NAME_STORAGE, &current, &limit);
        if (ret > 0) {
            left = limit < current ? 0 : limit - current;
            if (ctx->bytes_left > left)
                ctx->bytes_left = left;
        } else if (ret < 0) {
            ctx->failed = TRUE;
            break;
        }

        ret = quota_get_resource(roots[i], mailbox_name,
                     QUOTA_NAME_MESSAGES, &current, &limit);
        if (ret > 0) {
            left = limit < current ? 0 : limit - current;
            if (ctx->count_left > left)
                ctx->count_left = left;
        } else if (ret < 0) {
            ctx->failed = TRUE;
            break;
        }
    }
    return ctx;
}

int quota_transaction_commit(struct quota_transaction_context *ctx)
{
    struct quota_root *const *roots;
    unsigned int i, count;
    int ret = 0;

    if (ctx->failed)
        ret = -1;
    else {
        roots = array_get(&ctx->quota->roots, &count);
        for (i = 0; i < count; i++) {
            if (roots[i]->backend.v.update(roots[i], ctx) < 0)
                ret = -1;
        }
    }

    i_free(ctx);
    return ret;
}

void quota_transaction_rollback(struct quota_transaction_context *ctx)
{
    i_free(ctx);
}

int quota_try_alloc(struct quota_transaction_context *ctx,
            struct mail *mail, bool *too_large_r)
{
    int ret;

    ret = quota_test_alloc(ctx, mail_get_physical_size(mail), too_large_r);
    if (ret <= 0)
        return ret;

    quota_alloc(ctx, mail);
    return 1;
}

int quota_test_alloc(struct quota_transaction_context *ctx,
             uoff_t size, bool *too_large_r)
{
    return ctx->quota->test_alloc(ctx, size, too_large_r);
}

static int quota_default_test_alloc(struct quota_transaction_context *ctx,
                    uoff_t size, bool *too_large_r)
{
    struct quota_root *const *roots;
    unsigned int i, count;

    *too_large_r = FALSE;

    if (ctx->failed)
        return -1;
    if (ctx->count_left != 0 && ctx->bytes_left >= ctx->bytes_used + size)
        return 1;

    roots = array_get(&ctx->quota->roots, &count);
    for (i = 0; i < count; i++) {
        uint64_t bytes_limit, count_limit;

        if (!quota_root_get_rule_limits(roots[i],
                        mailbox_get_name(ctx->box),
                        &bytes_limit, &count_limit))
            continue;

        /* if size is bigger than any limit, then
           it is bigger than the lowest limit */
        if (size > bytes_limit) {
            *too_large_r = TRUE;
            break;
        }
    }

    return 0;
}

void quota_alloc(struct quota_transaction_context *ctx, struct mail *mail)
{
    uoff_t size;

    size = mail_get_physical_size(mail);
    if (size != (uoff_t)-1)
        ctx->bytes_used += size;

    ctx->count_used++;
}

void quota_free(struct quota_transaction_context *ctx, struct mail *mail)
{
    uoff_t size;

    size = mail_get_physical_size(mail);
    if (size != (uoff_t)-1)
        ctx->bytes_used -= size;

    ctx->count_used--;
}