timeout.c

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/*
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   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.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */
 
/**
 * $Id: bdc07ef5282bf445410591536b2900242529c2e9 $
 *
 * @file unlang/timeout.c
 * @brief Unlang "timeout" keyword evaluation.
 *
 * @copyright 2022 Network RADIUS SAS (legal@networkradius.com)
 */
RCSID("$Id: bdc07ef5282bf445410591536b2900242529c2e9 $")
 
#include <freeradius-devel/unlang/timeout.h>
#include <freeradius-devel/unlang/interpret.h>
#include <freeradius-devel/server/rcode.h>
#include "group_priv.h"
#include "timeout_priv.h"
#include "mod_action.h"
#include "unlang_priv.h"
 
typedef struct {
        bool                                    fired;
        int                                     depth;
        fr_time_delta_t                         timeout;
        request_t                               *request;
        rindent_t                               indent;
        fr_timer_t                              *ev;
 
        fr_value_box_list_t                     result;
 
        unlang_t                                *instruction;   //!< to run on timeout
} unlang_frame_state_timeout_t;
 
/** Immediately cancel the timeout if the frame is cancelled
 */
static void unlang_timeout_signal(UNUSED request_t *request, unlang_stack_frame_t *frame, fr_signal_t action)
{
        unlang_frame_state_timeout_t    *state = talloc_get_type_abort(frame->state, unlang_frame_state_timeout_t);
 
        if (action == FR_SIGNAL_CANCEL) {
                TALLOC_FREE(state->ev);
        }
}
 
static void unlang_timeout_handler(UNUSED fr_timer_list_t *tl, UNUSED fr_time_t now, void *ctx)
{
        unlang_frame_state_timeout_t    *state = talloc_get_type_abort(ctx, unlang_frame_state_timeout_t);
        request_t                       *request = talloc_get_type_abort(state->request, request_t);
        unlang_stack_t                  *stack = request->stack;
        unlang_stack_frame_t            *frame = &stack->frame[stack->depth];
        char const                      *module;
 
        /*
         *      Don't log in the context of the request
         */
        module = request->module;
        request->module = NULL;
        RDEBUG("Timeout reached, signalling interpreter to cancel child section.");
        request->module = module;
 
        /*
         *      Signal all the frames upto, but not including the timeout
         *      frame to cancel.
         *
         *      unlang_timeout_resume_done then runs, and returns "timeout"
         */
        unlang_stack_signal(request, FR_SIGNAL_CANCEL, state->depth);
 
        /*
         *      If the frame is yielded (needs to be resumed), but was cancelled
         *      we now need to mark it runnable again so it's unwound.
         *
         *      If the frame _isn't_ cancelled, then it's non-cancellable and
         *      something else will run it to completion, and mark
         *      the request as complete.
         */
        if (is_yielded(frame) && is_unwinding(frame) && !unlang_request_is_scheduled(request)) unlang_interpret_mark_runnable(request);
        state->fired = true;
 
        RINDENT_RESTORE(request, state);
 
        if (!state->instruction) return;
 
        /*
         *      Push something else onto the stack to execute.
         */
        if (unlikely(unlang_interpret_push_instruction(NULL, request, state->instruction,
                                                       FRAME_CONF(RLM_MODULE_TIMEOUT, true)) < 0)) {
                unlang_interpret_signal(request, FR_SIGNAL_CANCEL); /* also stops the request and does cleanups */
        }
}
 
static unlang_action_t unlang_timeout_resume_done(unlang_result_t *p_result, UNUSED request_t *request, unlang_stack_frame_t *frame)
{
        unlang_frame_state_timeout_t    *state = talloc_get_type_abort(frame->state, unlang_frame_state_timeout_t);
 
        /*
         *      No timeout, we go to the next instruction.
         *
         *      Unless the next instruction is a "catch timeout", in which case we skip it.
         */
        if (!state->fired) return UNLANG_ACTION_EXECUTE_NEXT;   /* Don't modify the return code*/
 
        RETURN_UNLANG_TIMEOUT;
}
 
static unlang_action_t unlang_timeout_set(UNUSED unlang_result_t *p_result, request_t *request, unlang_stack_frame_t *frame)
{
        unlang_frame_state_timeout_t    *state = talloc_get_type_abort(frame->state, unlang_frame_state_timeout_t);
 
        /*
         *      Save current indentation for the error path.
         */
        RINDENT_SAVE(state, request);
 
        if (fr_timer_in(state, unlang_interpret_event_list(request)->tl, &state->ev, state->timeout,
                        false, unlang_timeout_handler, state) < 0) {
                RPEDEBUG("Failed inserting event");
                return UNLANG_ACTION_STOP_PROCESSING;
        }
 
        frame_repeat(frame, unlang_timeout_resume_done);
 
        return unlang_interpret_push_children(NULL, request, RLM_MODULE_NOT_SET, UNLANG_NEXT_SIBLING);
}
 
static unlang_action_t unlang_timeout_done(unlang_result_t *p_result, request_t *request, unlang_stack_frame_t *frame)
{
        unlang_frame_state_timeout_t    *state = talloc_get_type_abort(frame->state, unlang_frame_state_timeout_t);
        fr_value_box_t                  *box = fr_value_box_list_head(&state->result);
 
        /*
         *      compile_timeout() ensures that the tmpl is cast to time_delta, so we don't have to do any more work here.
         */
        state->timeout = box->vb_time_delta;
 
        return unlang_timeout_set(p_result, request, frame);
}
 
static unlang_action_t unlang_timeout(unlang_result_t *p_result, request_t *request, unlang_stack_frame_t *frame)
{
        unlang_group_t                  *g;
        unlang_timeout_t                *gext;
        unlang_frame_state_timeout_t    *state = talloc_get_type_abort(frame->state, unlang_frame_state_timeout_t);
        unlang_stack_t                  *stack = request->stack;
 
        g = unlang_generic_to_group(frame->instruction);
        gext = unlang_group_to_timeout(g);
 
        /*
         *      +1 so we don't mark the timeout frame as cancelled,
         *      we want unlang_timeout_resume_done to be called.
         */
        state->depth = stack->depth + 1;
        state->request = request;
 
        if (!gext->vpt) {
                state->timeout = gext->timeout;
                return unlang_timeout_set(p_result, request, frame);
        }
 
        fr_value_box_list_init(&state->result);
 
        if (unlang_tmpl_push(state, &state->result, request, gext->vpt, NULL) < 0) return UNLANG_ACTION_FAIL;
 
        frame_repeat(frame, unlang_timeout_done);
 
        return UNLANG_ACTION_PUSHED_CHILD;
}
 
/** When a timeout fires, run the given section.
 *
 * @param[in] request           to push timeout onto
 * @param[in] timeout           when to run the timeout
 * @param[in] cs                section to run when the timeout fires.
 * @param[in] top_frame         Set to UNLANG_TOP_FRAME if the interpreter should return.
 *                              Set to UNLANG_SUB_FRAME if the interprer should continue.
 *
 * @return
 *      - 0 on success.
 *      - -1 on failure.
 */
int unlang_timeout_section_push(request_t *request, CONF_SECTION *cs, fr_time_delta_t timeout, bool top_frame)
{
        /** Static instruction for performing xlat evaluations
         *
         */
        static unlang_t timeout_instruction = {
                .type = UNLANG_TYPE_TIMEOUT,
                .name = "timeout",
                .debug_name = "timeout",
                .actions = {
                        .actions = {
                                [RLM_MODULE_REJECT]     = 0,
                                [RLM_MODULE_FAIL]       = MOD_ACTION_RETURN,    /* Exit out of nested levels */
                                [RLM_MODULE_OK]         = 0,
                                [RLM_MODULE_HANDLED]    = 0,
                                [RLM_MODULE_INVALID]    = 0,
                                [RLM_MODULE_DISALLOW]   = 0,
                                [RLM_MODULE_NOTFOUND]   = 0,
                                [RLM_MODULE_NOOP]       = 0,
                                [RLM_MODULE_TIMEOUT]    = MOD_ACTION_RETURN,    /* Exit out of nested levels */
                                [RLM_MODULE_UPDATED]    = 0
                        },
                        .retry = RETRY_INIT,
                },
        };
 
        unlang_frame_state_timeout_t    *state;
        unlang_stack_t                  *stack = request->stack;
        unlang_stack_frame_t            *frame;
        unlang_t                        *instruction;
 
        /*
         *      Get the instruction we are supposed to run on timeout.
         */
        instruction = (unlang_t *)cf_data_value(cf_data_find(cs, unlang_group_t, NULL));
        if (!instruction) {
                REDEBUG("Failed to find pre-compiled unlang for section %s { ... }",
                        cf_section_name1(cs));
                return -1;
        }
 
        /*
         *      Push a new timeout frame onto the stack
         */
        if (unlang_interpret_push(NULL, request, &timeout_instruction,
                                  FRAME_CONF(RLM_MODULE_NOT_SET, top_frame), UNLANG_NEXT_STOP) < 0) return -1;
        frame = &stack->frame[stack->depth];
 
        /*
         *      Allocate its state, and set the timeout.
         */
        MEM(frame->state = state = talloc_zero(stack, unlang_frame_state_timeout_t));
 
        RINDENT_SAVE(state, request);
        state->depth = stack->depth;
        state->request = request;
        state->timeout = timeout;
        state->instruction = instruction;
 
        if (fr_timer_in(state, unlang_interpret_event_list(request)->tl, &state->ev, timeout,
                        false, unlang_timeout_handler, state) < 0) {
                RPEDEBUG("Failed setting timeout for section %s", cf_section_name1(cs));
                return -1;
        }
 
        frame_repeat(frame, unlang_timeout_resume_done);
 
        return 0;
 
}
 
static unlang_t *unlang_compile_timeout(unlang_t *parent, unlang_compile_ctx_t *unlang_ctx, CONF_ITEM const *ci)
{
        CONF_SECTION            *cs = cf_item_to_section(ci);
        char const              *name2;
        unlang_t                *c;
        unlang_group_t          *g;
        unlang_timeout_t        *gext;
        fr_time_delta_t         timeout = fr_time_delta_from_sec(0);
        tmpl_t                  *vpt = NULL;
        fr_token_t              token;
 
        /*
         *      Timeout <time ref>
         */
        name2 = cf_section_name2(cs);
        if (!name2) {
                cf_log_err(cs, "You must specify a time value for 'timeout'");
        print_url:
                cf_log_err(ci, DOC_KEYWORD_REF(timeout));
                return NULL;
        }
 
        if (!cf_item_next(cs, NULL)) return UNLANG_IGNORE;
 
        g = unlang_group_allocate(parent, cs, UNLANG_TYPE_TIMEOUT);
        if (!g) return NULL;
 
        gext = unlang_group_to_timeout(g);
 
        token = cf_section_name2_quote(cs);
 
        if ((token == T_BARE_WORD) && isdigit((uint8_t) *name2)) {
                if (fr_time_delta_from_str(&timeout, name2, strlen(name2), FR_TIME_RES_SEC) < 0) {
                        cf_log_err(cs, "Failed parsing time delta %s - %s",
                                   name2, fr_strerror());
                        return NULL;
                }
        } else {
                ssize_t         slen;
                tmpl_rules_t    t_rules;
 
                /*
                 *      We don't allow unknown attributes here.
                 */
                t_rules = *(unlang_ctx->rules);
                t_rules.attr.allow_unknown = false;
                RULES_VERIFY(&t_rules);
 
                slen = tmpl_afrom_substr(gext, &vpt,
                                         &FR_SBUFF_IN(name2, strlen(name2)),
                                         token,
                                         NULL,
                                         &t_rules);
                if (!vpt) {
                        cf_canonicalize_error(cs, slen, "Failed parsing argument to 'timeout'", name2);
                        talloc_free(g);
                        return NULL;
                }
 
                /*
                 *      Fixup the tmpl so that we know it's somewhat sane.
                 */
                if (!pass2_fixup_tmpl(gext, &vpt, cf_section_to_item(cs), unlang_ctx->rules->attr.dict_def)) {
                        talloc_free(g);
                        return NULL;
                }
 
                if (tmpl_is_list(vpt)) {
                        cf_log_err(cs, "Cannot use list as argument for 'timeout' statement");
                error:
                        talloc_free(g);
                        goto print_url;
                }
 
                if (tmpl_contains_regex(vpt)) {
                        cf_log_err(cs, "Cannot use regular expression as argument for 'timeout' statement");
                        goto error;
                }
 
                /*
                 *      Attribute or data MUST be cast to TIME_DELTA.
                 */
                if (tmpl_cast_set(vpt, FR_TYPE_TIME_DELTA) < 0) {
                        cf_log_perr(cs, "Failed setting cast type");
                        goto error;
                }
        }
 
        /*
         *      Compile the contents of a "timeout".
         */
        c = unlang_compile_section(parent, unlang_ctx, cs, UNLANG_TYPE_TIMEOUT);
        if (!c) return NULL;
 
        g = unlang_generic_to_group(c);
        gext = unlang_group_to_timeout(g);
        gext->timeout = timeout;
        gext->vpt = vpt;
 
        return c;
}
 
void unlang_timeout_init(void)
{
        unlang_register(&(unlang_op_t){
                        .name = "timeout",
                        .type = UNLANG_TYPE_TIMEOUT,
                        .flag = UNLANG_OP_FLAG_DEBUG_BRACES | UNLANG_OP_FLAG_RCODE_SET,
 
                        .compile = unlang_compile_timeout,
                        .interpret = unlang_timeout,
                        .signal = unlang_timeout_signal,
 
                        .unlang_size = sizeof(unlang_timeout_t),
                        .unlang_name = "unlang_timeout_t",
 
                        .frame_state_size = sizeof(unlang_frame_state_timeout_t),
                        .frame_state_type = "unlang_frame_state_timeout_t",
                });
}