xref: /f-stack/tools/compat/sysctl.c (revision df6ad731)
1 /*
2  * Copyright (C) 2017 THL A29 Limited, a Tencent company.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright notice, this
9  *   list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright notice,
11  *   this list of conditions and the following disclaimer in the documentation
12  *   and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
16  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
17  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
18  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
19  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
20  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
21  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
23  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  *
25  */
26 
27 #include <string.h>
28 
29 #include "ff_ipc.h"
30 
31 int
32 sysctl(int *name, unsigned namelen, void *old,
33     size_t *oldlenp, const void *new, size_t newlen)
34 {
35     struct ff_msg *msg, *retmsg = NULL;
36 
37     if (old != NULL && oldlenp == NULL) {
38         errno = EINVAL;
39         return -1;
40     }
41 
42     msg = ff_ipc_msg_alloc();
43     if (msg == NULL) {
44         errno = ENOMEM;
45         return -1;
46     }
47 
48     size_t oldlen = 0;
49     if (old && oldlenp) {
50         oldlen = *oldlenp;
51     }
52 
53     if (namelen + oldlen + newlen > msg->buf_len) {
54         errno = EINVAL;
55         ff_ipc_msg_free(msg);
56         return -1;
57     }
58 
59     char *buf_addr = msg->buf_addr;
60 
61     msg->msg_type = FF_SYSCTL;
62     msg->sysctl.name = (int *)buf_addr;
63     msg->sysctl.namelen = namelen;
64     memcpy(msg->sysctl.name, name, namelen*sizeof(int));
65 
66     buf_addr += namelen*sizeof(int);
67 
68     if (new != NULL && newlen != 0) {
69         msg->sysctl.new = buf_addr;
70         msg->sysctl.newlen = newlen;
71         memcpy(msg->sysctl.new, new, newlen);
72 
73         buf_addr += newlen;
74     } else {
75         msg->sysctl.new = NULL;
76         msg->sysctl.newlen = 0;
77     }
78 
79     if (oldlenp != NULL) {
80         msg->sysctl.oldlenp = (size_t *)buf_addr;
81         memcpy(msg->sysctl.oldlenp, oldlenp, sizeof(size_t));
82         buf_addr += sizeof(size_t);
83 
84         if (old != NULL) {
85             msg->sysctl.old = (void *)buf_addr;
86             memcpy(msg->sysctl.old, old, *oldlenp);
87             buf_addr += *oldlenp;
88         } else {
89             msg->sysctl.old = NULL;
90         }
91     } else {
92         msg->sysctl.oldlenp = NULL;
93         msg->sysctl.old = NULL;
94     }
95 
96     int ret = ff_ipc_send(msg);
97     if (ret < 0) {
98         errno = EPIPE;
99         ff_ipc_msg_free(msg);
100         return -1;
101     }
102 
103     do {
104         if (retmsg != NULL) {
105             ff_ipc_msg_free(retmsg);
106         }
107         ret = ff_ipc_recv(&retmsg);
108         if (ret < 0) {
109             errno = EPIPE;
110             ff_ipc_msg_free(msg);
111             return -1;
112         }
113     } while (msg != retmsg);
114 
115     if (retmsg->result == 0) {
116         ret = 0;
117         if (oldlenp && retmsg->sysctl.oldlenp) {
118             *oldlenp = *retmsg->sysctl.oldlenp;
119         }
120 
121         if (old && retmsg->sysctl.old && oldlenp) {
122             memcpy(old, retmsg->sysctl.old, *oldlenp);
123         }
124     } else {
125         ret = -1;
126         errno = retmsg->result;
127     }
128 
129     ff_ipc_msg_free(msg);
130 
131     return ret;
132 }
133