1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
|
/*
* libvdeplug - A library to connect to a VDE Switch.
* Copyright (C) 2017 Renzo Davoli, University of Bologna
*
* Stream vde to a command
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation version 2.1 of the License, or (at
* your option) any later version.
*
* This library 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 Lesser
* General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <libvdeplug.h>
#include <errno.h>
#include <limits.h>
#include <stdint.h>
#include <poll.h>
#include <signal.h>
#include <sys/stat.h>
#include <sys/uio.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <execs.h>
#include "libvdeplug_mod.h"
static VDECONN *vde_cmd_open(char *given_vde_url, char *descr,int interface_version,
struct vde_open_args *open_args);
static ssize_t vde_cmd_recv(VDECONN *conn,void *buf,size_t len,int flags);
static ssize_t vde_cmd_send(VDECONN *conn,const void *buf,size_t len,int flags);
static int vde_cmd_datafd(VDECONN *conn);
static int vde_cmd_ctlfd(VDECONN *conn);
static int vde_cmd_close(VDECONN *conn);
struct vdeplug_module vdeplug_ops={
.vde_open_real=vde_cmd_open,
.vde_recv=vde_cmd_recv,
.vde_send=vde_cmd_send,
.vde_datafd=vde_cmd_datafd,
.vde_ctlfd=vde_cmd_ctlfd,
.vde_close=vde_cmd_close};
struct vde_cmd_conn {
void *handle;
struct vdeplug_module *module;
char *cmdstring;
pid_t cmd_pid;
int cmd_fd[2];
};
static VDECONN *vde_cmd_open(char *cmdstring, char *descr,int interface_version,
struct vde_open_args *open_args)
{
struct vde_cmd_conn *newconn;
if ((newconn=calloc(1,sizeof(struct vde_cmd_conn)))==NULL)
{
errno=ENOMEM;
goto abort;
}
newconn->cmdstring = strdup(cmdstring);
if ((newconn->cmd_pid = coprocsp(cmdstring, newconn->cmd_fd)) < 0)
goto free_abort;
return (VDECONN *)newconn;
free_abort:
free(newconn);
abort:
return NULL;
}
static ssize_t vde_cmd_recv(VDECONN *conn,void *buf,size_t len,int flags)
{
struct vde_cmd_conn *vde_conn = (struct vde_cmd_conn *)conn;
unsigned char header[2];
unsigned int pktlen;
ssize_t rv;
struct pollfd pollok = {vde_conn->cmd_fd[0], POLLIN, 0};
if ((rv = read(vde_conn->cmd_fd[0], header, 2)) != 2)
goto error;
pktlen = (header[0]<<8) + header[1];
if (pktlen > VDE_ETHBUFSIZE)
goto error;
if (poll(&pollok,1,0) <= 0)
goto error;
if (pktlen <= len) {
if ((rv = read(vde_conn->cmd_fd[0], buf, pktlen)) != pktlen)
goto error;
return rv;
} else {
ssize_t taillen = pktlen - len;
unsigned char tail[taillen];
struct iovec iov[2]={{buf, len}, {tail, taillen}};
if ((rv = readv(vde_conn->cmd_fd[0], iov, 2)) != pktlen)
goto error;
return len;
}
error:
if (rv < 0) {
return rv;
} else if (rv == 0) { // the command terminated
int fd[2];
int status;
pipe(fd);
dup2(fd[0], vde_conn->cmd_fd[0]);
dup2(fd[1], vde_conn->cmd_fd[1]);
waitpid(vde_conn->cmd_pid, &status, WNOHANG); /* discard exit status */
fprintf(stderr, "VDE terminated: cmd://%s\n",vde_conn->cmdstring);
return rv;
} else {
errno = EAGAIN;
return 1;
}
}
static ssize_t vde_cmd_send(VDECONN *conn,const void *buf,size_t len,int flags)
{
struct vde_cmd_conn *vde_conn = (struct vde_cmd_conn *)conn;
if (len <= VDE_ETHBUFSIZE) {
unsigned char header[2];
struct iovec iov[2]={{header,2},{(void *)buf,len}};
header[0]=len >> 8;
header[1]=len & 0xff;
return writev(vde_conn->cmd_fd[1],iov,2);
} else
return 0;
}
static int vde_cmd_datafd(VDECONN *conn)
{
struct vde_cmd_conn *vde_conn = (struct vde_cmd_conn *)conn;
return vde_conn->cmd_fd[0];
}
static int vde_cmd_ctlfd(VDECONN *conn)
{
return -1;
}
static int vde_cmd_close(VDECONN *conn)
{
struct vde_cmd_conn *vde_conn = (struct vde_cmd_conn *)conn;
int status;
close(vde_conn->cmd_fd[1]);
close(vde_conn->cmd_fd[0]);
kill(SIGTERM, vde_conn->cmd_pid);
waitpid(vde_conn->cmd_pid, &status, 0); /* discard exit status */
if (vde_conn->cmdstring)
free(vde_conn->cmdstring);
free(vde_conn);
return 0;
}
|
