1 /*
2  * Copyright (C) 2021 Huawei Device Co., Ltd.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at
6  *
7  *     http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 
16 #include "nstackx_event.h"
17 #include "nstackx_log.h"
18 #include "nstackx_error.h"
19 #include "nstackx_util.h"
20 #include "securec.h"
21 
22 #define TAG "nStackXEvent"
23 
24 typedef struct {
25     EventHandle handle;
26     void *arg;
27 } EventInfo;
28 
29 EventNode *SearchEventNode(const List *eventNodeChain, EpollDesc epollfd);
30 
CloseNodePipe(const EventNode * node)31 void CloseNodePipe(const EventNode *node)
32 {
33     CloseDesc(node->pipeFd[PIPE_OUT]);
34     CloseDesc(node->pipeFd[PIPE_IN]);
35 }
36 
EventProcessHandle(void * arg)37 static void EventProcessHandle(void *arg)
38 {
39     int32_t ret;
40     EventInfo event = {0};
41     EpollTask *task = arg;
42     EventNode *node = container_of(task, EventNode, task);
43 
44     ret = (int32_t)read(node->pipeFd[PIPE_OUT], &event, sizeof(event));
45     if (ret != (int32_t)sizeof(event)) {
46         LOGE(TAG, "failed to read from pipe: %d", GetErrno());
47         return;
48     }
49 
50     if (event.handle != NULL) {
51         event.handle(event.arg);
52     }
53 }
54 
PostEvent(const List * eventNodeChain,EpollDesc epollfd,EventHandle handle,void * arg)55 int32_t PostEvent(const List *eventNodeChain, EpollDesc epollfd, EventHandle handle, void *arg)
56 {
57     int32_t ret;
58     EventNode *node = NULL;
59     EventInfo event = {
60         .handle = handle,
61         .arg = arg,
62     };
63 
64     if (eventNodeChain == NULL || handle == NULL) {
65         return NSTACKX_EINVAL;
66     }
67 
68     node = SearchEventNode(eventNodeChain, epollfd);
69     if (node == NULL) {
70         LOGE(TAG, "Cannot find event node for %d", epollfd);
71         return NSTACKX_EFAILED;
72     }
73 
74     ret = (int32_t)write(node->pipeFd[PIPE_IN], &event, sizeof(event));
75     if (ret != (int32_t)sizeof(event)) {
76         LOGE(TAG, "failed to write to pipe: %d", errno);
77         return NSTACKX_EFAILED;
78     }
79     return NSTACKX_EOK;
80 }
81 
ClearEvent(const List * eventNodeChain,EpollDesc epollfd)82 void ClearEvent(const List *eventNodeChain, EpollDesc epollfd)
83 {
84     EventNode *node = NULL;
85     EventInfo event = {0};
86     int32_t eventLen = (int32_t)sizeof(event);
87     if (eventNodeChain == NULL) {
88         LOGE(TAG, "eventNodeChain is null");
89         return;
90     }
91 
92     node = SearchEventNode(eventNodeChain, epollfd);
93     if (node == NULL) {
94         return;
95     }
96 
97     int32_t ret = eventLen;
98     while (ret == eventLen) {
99         ret = (int32_t)read(node->pipeFd[PIPE_OUT], &event, sizeof(event));
100         if (ret != eventLen) {
101             break;
102         }
103 
104         if (event.handle != NULL) {
105             event.handle(event.arg);
106         }
107     }
108 }
109 
CreateNonBlockPipe(EventNode * node)110 static int32_t CreateNonBlockPipe(EventNode *node)
111 {
112     int32_t ret;
113     int32_t i, flags;
114 
115     if (pipe(node->pipeFd) < 0) {
116         LOGE(TAG, "create pipe error: %d", errno);
117         return NSTACKX_EFAILED;
118     }
119 
120     for (i = 0; i < PIPE_FD_NUM; i++) {
121         flags = fcntl(node->pipeFd[i], F_GETFL, 0);
122         if (flags < 0) {
123             LOGE(TAG, "fcntl get flags failed: %d", errno);
124             CloseNodePipe(node);
125             return NSTACKX_EFAILED;
126         }
127 
128         flags = (int32_t)((uint32_t)flags | O_NONBLOCK);
129         ret = fcntl(node->pipeFd[i], F_SETFL, flags);
130         if (ret < 0) {
131             LOGE(TAG, "fcntl set flags to non-blocking failed: %d", errno);
132             CloseNodePipe(node);
133             return NSTACKX_EFAILED;
134         }
135     }
136 
137     return NSTACKX_EOK;
138 }
139 
EventModuleInit(List * eventNodeChain,EpollDesc epollfd)140 int32_t EventModuleInit(List *eventNodeChain, EpollDesc epollfd)
141 {
142     List *pos = NULL;
143     EventNode *node = NULL;
144     if (eventNodeChain == NULL) {
145         LOGE(TAG, "eventNodeChain is null");
146         return NSTACKX_EINVAL;
147     }
148     LIST_FOR_EACH(pos, eventNodeChain) {
149         node = (EventNode *)pos;
150         if (node->epollfd == epollfd) {
151             return NSTACKX_EOK;
152         }
153     }
154 
155     node = calloc(1, sizeof(EventNode));
156     if (node == NULL) {
157         return NSTACKX_ENOMEM;
158     }
159 
160     if (CreateNonBlockPipe(node) != NSTACKX_EOK) {
161         goto L_ERR_FAILED;
162     }
163 
164     node->task.taskfd = node->pipeFd[PIPE_OUT];
165     node->task.epollfd = epollfd;
166     node->task.readHandle = EventProcessHandle;
167 
168     node->epollfd = epollfd;
169     if (RegisterEpollTask(&node->task, EPOLLIN) != NSTACKX_EOK) {
170         LOGE(TAG, "RegisterEpollTask failed");
171         CloseNodePipe(node);
172         goto L_ERR_FAILED;
173     }
174 
175     ListInsertTail(eventNodeChain, &(node->list));
176     return NSTACKX_EOK;
177 L_ERR_FAILED:
178     free(node);
179     return NSTACKX_EFAILED;
180 }
181 
DeleteEventNode(EventNode * node)182 void DeleteEventNode(EventNode *node)
183 {
184     ListRemoveNode(&node->list);
185     if (DeRegisterEpollTask(&node->task) != NSTACKX_EOK) {
186         LOGE(TAG, "DeRegisterEpollTask failed");
187     }
188     CloseNodePipe(node);
189     free(node);
190 }
191