libubus-req.c

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/*
 * Copyright (C) 2011-2014 Felix Fietkau <nbd@openwrt.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation
 *
 * 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.
 */
 
#include <unistd.h>
#include "libubus.h"
#include "libubus-internal.h"
 
struct ubus_pending_data {
        struct list_head list;
        int type;
        struct blob_attr data[];
};
 
static void req_data_cb(struct ubus_request *req, int type, struct blob_attr *data)
{
        struct blob_attr **attr;
 
        if (req->raw_data_cb)
                req->raw_data_cb(req, type, data);
 
        if (!req->data_cb)
                return;
 
        attr = ubus_parse_msg(data, blob_raw_len(data));
        if (!attr[UBUS_ATTR_DATA])
                return;
 
        req->data_cb(req, type, attr[UBUS_ATTR_DATA]);
}
 
static void __ubus_process_req_data(struct ubus_request *req)
{
        struct ubus_pending_data *data, *tmp;
 
        list_for_each_entry_safe(data, tmp, &req->pending, list) {
                list_del(&data->list);
                if (!req->cancelled)
                        req_data_cb(req, data->type, data->data);
                free(data);
        }
}
 
int __hidden __ubus_start_request(struct ubus_context *ctx, struct ubus_request *req,
                                struct blob_attr *msg, int cmd, uint32_t peer)
{
 
        if (msg && blob_pad_len(msg) > UBUS_MAX_MSGLEN)
                return -1;
 
        INIT_LIST_HEAD(&req->list);
        INIT_LIST_HEAD(&req->pending);
        req->ctx = ctx;
        req->peer = peer;
        req->seq = ++ctx->request_seq;
 
        return ubus_send_msg(ctx, req->seq, msg, cmd, peer, req->fd);
}
 
int __hidden ubus_start_request(struct ubus_context *ctx, struct ubus_request *req,
                                struct blob_attr *msg, int cmd, uint32_t peer)
{
        memset(req, 0, sizeof(*req));
 
        req->fd = -1;
 
        return __ubus_start_request(ctx, req, msg, cmd, peer);
}
 
 
void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req)
{
        if (list_empty(&req->list))
                return;
 
        req->cancelled = true;
        __ubus_process_req_data(req);
        list_del_init(&req->list);
}
 
void ubus_complete_request_async(struct ubus_context *ctx, struct ubus_request *req)
{
        if (!list_empty(&req->list))
                return;
 
        list_add(&req->list, &ctx->requests);
}
 
static void
ubus_req_complete_cb(struct ubus_request *req)
{
        ubus_complete_handler_t cb = req->complete_cb;
 
        if (!cb)
                return;
 
        req->complete_cb = NULL;
        cb(req, req->status_code);
}
 
static void
ubus_set_req_status(struct ubus_request *req, int ret)
{
        if (!list_empty(&req->list))
                list_del_init(&req->list);
 
        req->status_msg = true;
        req->status_code = ret;
        if (!req->blocked)
                ubus_req_complete_cb(req);
}
 
static void ubus_sync_req_cb(struct ubus_request *req, int ret)
{
        req->status_msg = true;
        req->status_code = ret;
        req->ctx->cancel_poll = true;
}
 
static int64_t get_time_msec(void)
{
        struct timespec ts;
        int64_t val;
 
        clock_gettime(CLOCK_MONOTONIC, &ts);
        val = (int64_t) ts.tv_sec * 1000LL;
        val += ts.tv_nsec / 1000000LL;
        return val;
}
 
int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
                          int req_timeout)
{
        ubus_complete_handler_t complete_cb = req->complete_cb;
        int status = UBUS_STATUS_NO_DATA;
        int64_t timeout = 0, time_end = 0;
 
        if (req_timeout)
                time_end = get_time_msec() + req_timeout;
 
        ubus_complete_request_async(ctx, req);
        req->complete_cb = ubus_sync_req_cb;
 
        ctx->stack_depth++;
        while (!req->status_msg) {
                if (req_timeout) {
                        timeout = time_end - get_time_msec();
                        if (timeout <= 0) {
                                ubus_set_req_status(req, UBUS_STATUS_TIMEOUT);
                                break;
                        }
                }
 
                ubus_poll_data(ctx, (unsigned int) timeout);
 
                if (ctx->sock.eof) {
                        ubus_set_req_status(req, UBUS_STATUS_CONNECTION_FAILED);
                        ctx->cancel_poll = true;
                        break;
                }
        }
 
        ctx->stack_depth--;
        if (ctx->stack_depth)
                ctx->cancel_poll = true;
 
        if (req->status_msg)
                status = req->status_code;
 
        req->complete_cb = complete_cb;
        if (req->complete_cb)
                req->complete_cb(req, status);
 
        if (!ctx->stack_depth && !ctx->sock.registered)
                ctx->pending_timer.cb(&ctx->pending_timer);
 
        return status;
}
 
void ubus_complete_deferred_request(struct ubus_context *ctx, struct ubus_request_data *req, int ret)
{
        blob_buf_init(&b, 0);
        blob_put_int32(&b, UBUS_ATTR_STATUS, ret);
        blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
        ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_STATUS, req->peer, req->fd);
}
 
static void ubus_put_data(struct blob_buf *buf, struct blob_attr *msg)
{
        if (msg)
                blob_put(buf, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
        else
                blob_put(buf, UBUS_ATTR_DATA, NULL, 0);
}
 
int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
                    struct blob_attr *msg)
{
        int ret;
 
        blob_buf_init(&b, 0);
        blob_put_int32(&b, UBUS_ATTR_OBJID, req->object);
        ubus_put_data(&b, msg);
        ret = ubus_send_msg(ctx, req->seq, b.head, UBUS_MSG_DATA, req->peer, -1);
        if (ret < 0)
                return UBUS_STATUS_NO_DATA;
 
        return 0;
}
 
int ubus_invoke_async_fd(struct ubus_context *ctx, uint32_t obj,
                         const char *method, struct blob_attr *msg,
                         struct ubus_request *req, int fd)
{
        blob_buf_init(&b, 0);
        blob_put_int32(&b, UBUS_ATTR_OBJID, obj);
        blob_put_string(&b, UBUS_ATTR_METHOD, method);
        ubus_put_data(&b, msg);
 
        memset(req, 0, sizeof(*req));
        req->fd = fd;
        if (__ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj) < 0)
                return UBUS_STATUS_INVALID_ARGUMENT;
        return 0;
}
 
int ubus_invoke_fd(struct ubus_context *ctx, uint32_t obj, const char *method,
                   struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
                   int timeout, int fd)
{
        struct ubus_request req;
        int rc;
 
        rc = ubus_invoke_async_fd(ctx, obj, method, msg, &req, fd);
        if (rc)
                return rc;
 
        req.data_cb = cb;
        req.priv = priv;
        return ubus_complete_request(ctx, &req, timeout);
}
 
static void
ubus_notify_complete_cb(struct ubus_request *req, int ret)
{
        struct ubus_notify_request *nreq;
 
        nreq = container_of(req, struct ubus_notify_request, req);
        if (!nreq->complete_cb)
                return;
 
        nreq->complete_cb(nreq, 0, 0);
}
 
static void
ubus_notify_data_cb(struct ubus_request *req, int type, struct blob_attr *msg)
{
        struct ubus_notify_request *nreq;
 
        nreq = container_of(req, struct ubus_notify_request, req);
        if (!nreq->data_cb)
                return;
 
        nreq->data_cb(nreq, type, msg);
}
 
static int
__ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
                    const char *type, struct blob_attr *msg,
                    struct ubus_notify_request *req, bool reply)
{
        memset(req, 0, sizeof(*req));
 
        blob_buf_init(&b, 0);
        blob_put_int32(&b, UBUS_ATTR_OBJID, obj->id);
        blob_put_string(&b, UBUS_ATTR_METHOD, type);
        ubus_put_data(&b, msg);
 
        if (!reply)
                blob_put_int8(&b, UBUS_ATTR_NO_REPLY, true);
 
        if (ubus_start_request(ctx, &req->req, b.head, UBUS_MSG_NOTIFY, obj->id) < 0)
                return UBUS_STATUS_INVALID_ARGUMENT;
 
        /* wait for status message from ubusd first */
        req->req.notify = true;
        req->pending = 1;
        req->id[0] = obj->id;
        req->req.complete_cb = ubus_notify_complete_cb;
        req->req.data_cb = ubus_notify_data_cb;
 
        return 0;
}
 
int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
                      const char *type, struct blob_attr *msg,
                      struct ubus_notify_request *req)
{
        return __ubus_notify_async(ctx, obj, type, msg, req, true);
}
 
int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
                const char *type, struct blob_attr *msg, int timeout)
{
        struct ubus_notify_request req;
        int ret;
 
        ret = __ubus_notify_async(ctx, obj, type, msg, &req, timeout >= 0);
        if (ret < 0)
                return ret;
 
        if (timeout < 0) {
                ubus_abort_request(ctx, &req.req);
                return 0;
        }
 
        return ubus_complete_request(ctx, &req.req, timeout);
}
 
static bool ubus_get_status(struct ubus_msghdr_buf *buf, int *ret)
{
        struct blob_attr **attrbuf = ubus_parse_msg(buf->data, blob_raw_len(buf->data));
 
        if (!attrbuf[UBUS_ATTR_STATUS])
                return false;
 
        *ret = blob_get_u32(attrbuf[UBUS_ATTR_STATUS]);
        return true;
}
 
static int
ubus_process_req_status(struct ubus_request *req, struct ubus_msghdr_buf *buf)
{
        int ret = UBUS_STATUS_INVALID_ARGUMENT;
 
        ubus_get_status(buf, &ret);
        req->peer = buf->hdr.peer;
        ubus_set_req_status(req, ret);
 
        return ret;
}
 
static void
ubus_process_req_data(struct ubus_request *req, struct ubus_msghdr_buf *buf)
{
        struct ubus_pending_data *data;
        int len;
 
        if (!req->blocked) {
                req->blocked = true;
                req_data_cb(req, buf->hdr.type, buf->data);
                __ubus_process_req_data(req);
                req->blocked = false;
 
                if (req->status_msg)
                        ubus_req_complete_cb(req);
 
                return;
        }
 
        len = blob_raw_len(buf->data);
        data = calloc(1, sizeof(*data) + len);
        if (!data)
                return;
 
        data->type = buf->hdr.type;
        memcpy(data->data, buf->data, len);
        list_add(&data->list, &req->pending);
}
 
static int
ubus_find_notify_id(struct ubus_notify_request *n, uint32_t objid)
{
        uint32_t pending = n->pending;
        int i;
 
        for (i = 0; pending; i++, pending >>= 1) {
                if (!(pending & 1))
                        continue;
 
                if (n->id[i] == objid)
                        return i;
        }
 
        return -1;
}
 
static struct ubus_request *
ubus_find_request(struct ubus_context *ctx, uint32_t seq, uint32_t peer, int *id)
{
        struct ubus_request *req;
 
        list_for_each_entry(req, &ctx->requests, list) {
                struct ubus_notify_request *nreq;
                nreq = container_of(req, struct ubus_notify_request, req);
 
                if (seq != req->seq)
                        continue;
 
                if (req->notify) {
                        if (!nreq->pending)
                                continue;
 
                        *id = ubus_find_notify_id(nreq, peer);
                        if (*id < 0)
                                continue;
                } else if (peer != req->peer)
                        continue;
 
                return req;
        }
        return NULL;
}
 
static void ubus_process_notify_status(struct ubus_request *req, int id, struct ubus_msghdr_buf *buf)
{
        struct ubus_notify_request *nreq;
        struct blob_attr **tb;
        struct blob_attr *cur;
        size_t rem;
        int idx = 1;
        int ret = 0;
 
        nreq = container_of(req, struct ubus_notify_request, req);
        nreq->pending &= ~(1 << id);
 
        if (!id) {
                /* first id: ubusd's status message with a list of ids */
                tb = ubus_parse_msg(buf->data, blob_raw_len(buf->data));
                if (tb[UBUS_ATTR_SUBSCRIBERS]) {
                        blob_for_each_attr(cur, tb[UBUS_ATTR_SUBSCRIBERS], rem) {
                                if (!blob_check_type(blob_data(cur), blob_len(cur), BLOB_ATTR_INT32))
                                        continue;
 
                                nreq->pending |= (1 << idx);
                                nreq->id[idx] = blob_get_int32(cur);
                                idx++;
 
                                if (idx == UBUS_MAX_NOTIFY_PEERS + 1)
                                        break;
                        }
                }
        } else {
                ubus_get_status(buf, &ret);
                if (nreq->status_cb)
                        nreq->status_cb(nreq, id, ret);
        }
 
        if (!nreq->pending)
                ubus_set_req_status(req, 0);
}
 
void __hidden ubus_process_req_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf, int fd)
{
        struct ubus_msghdr *hdr = &buf->hdr;
        struct ubus_request *req;
        int id = -1;
 
        switch(hdr->type) {
        case UBUS_MSG_STATUS:
                req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
                if (!req)
                        break;
 
                if (fd >= 0) {
                        if (req->fd_cb)
                                req->fd_cb(req, fd);
                        else
                                close(fd);
                }
 
                if (id >= 0)
                        ubus_process_notify_status(req, id, buf);
                else
                        ubus_process_req_status(req, buf);
                break;
 
        case UBUS_MSG_DATA:
                req = ubus_find_request(ctx, hdr->seq, hdr->peer, &id);
                if (req && (req->data_cb || req->raw_data_cb))
                        ubus_process_req_data(req, buf);
                break;
        }
}
 
int __ubus_monitor(struct ubus_context *ctx, const char *type)
{
        blob_buf_init(&b, 0);
        return ubus_invoke(ctx, UBUS_SYSTEM_OBJECT_MONITOR, type, b.head, NULL, NULL, 1000);
}