C Unix域套接字传递文件描述符-sendmsg:未连接传输终结点
我一直在阅读博客和这里的各种问题,因此试图了解如何使用Unix域套接字传递文件描述符。但是,我不断收到sendmsg错误-“传输端点未连接” 如果有人能帮助我理解我做错了什么,我将不胜感激 服务器:C Unix域套接字传递文件描述符-sendmsg:未连接传输终结点,c,linux,sockets,unix,C,Linux,Sockets,Unix,我一直在阅读博客和这里的各种问题,因此试图了解如何使用Unix域套接字传递文件描述符。但是,我不断收到sendmsg错误-“传输端点未连接” 如果有人能帮助我理解我做错了什么,我将不胜感激 服务器: #include <stdio.h> #include <sys/socket.h> #include <sys/un.h> #include <stdlib.h> #include <unistd.h> #include <QDeb
#include <stdio.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <stdlib.h>
#include <unistd.h>
#include <QDebug>
char *socket_path = "/.socket";
ssize_t sock_fd_write(int sock, void *buf, ssize_t buflen, int fd)
{
ssize_t size;
struct msghdr msg;
struct iovec iov;
union {
struct cmsghdr cmsghdr;
char control[CMSG_SPACE(sizeof (int))];
} cmsgu;
struct cmsghdr *cmsg;
iov.iov_base = buf;
iov.iov_len = buflen;
msg.msg_name = NULL;
msg.msg_namelen = 0;
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
if (fd != -1) {
msg.msg_control = cmsgu.control;
msg.msg_controllen = sizeof(cmsgu.control);
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_len = CMSG_LEN(sizeof (int));
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
printf ("passing fd %d\n", fd);
*((int *) CMSG_DATA(cmsg)) = fd;
} else {
msg.msg_control = NULL;
msg.msg_controllen = 0;
printf ("not passing fd\n");
}
printf ("sendmsg: %d\n", sock);
size = sendmsg(sock, &msg, 0);
if (size < 0)
perror ("sendmsg");
return size;
}
int main(int argc, char *argv[]) {
struct sockaddr_un addr;
char buf[100];
int fd,cl,rc;
if ( (fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
perror("socket error");
exit(-1);
}
qDebug() << "Created Socket";
memset(&addr, 0, sizeof(addr));
addr.sun_family = AF_UNIX;
strncpy(addr.sun_path, socket_path, sizeof(addr.sun_path)-1);
unlink(socket_path);
int reuse = 1;
int err = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &reuse, sizeof(reuse));
if (0 == err) {
err = bind(fd, (struct sockaddr*)&addr, sizeof(addr));
if ( err == -1 ) {
perror("bind error");
exit(-1);
}
}
qDebug() << "Bound socket: " << fd;
if (listen(fd, 5) == -1) {
perror("listen error");
exit(-1);
}
qDebug() << "Listening";
while (1) {
qDebug() << "About to accept";
if ( (cl = accept(fd, NULL, NULL)) == -1) {
perror("accept error");
qDebug() << "Accept error";
continue;
}
while ( (rc=read(cl,buf,sizeof(buf))) > 0) {
printf("read %u bytes: %.*s\n", rc, rc, buf);
qDebug() << "sock_fd_write: " << fd;
ssize_t size;
size = sock_fd_write(fd, (void*)"1", 1, 1);
printf ("wrote %d\n", size);
}
if (rc == -1) {
perror("read");
exit(-1);
}
else if (rc == 0) {
printf("EOF\n");
close(cl);
}
}
return 0;
}
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char*socket_path=“/.socket”;
ssize_t sock_fd_write(int sock,void*buf,ssize_t buflen,int fd)
{
大小;
结构msghdr msg;
结构iovec iov;
联合{
结构cmsghdr-cmsghdr;
字符控制[CMSG_空间(sizeof(int))];
}cmsgu;
结构cmsghdr*cmsg;
iov.iov_base=buf;
iov.iov_len=buflen;
msg.msg_name=NULL;
msg.msg_namelen=0;
msg.msg_iov=&iov;
msg.msg_iovlen=1;
如果(fd!=-1){
msg.msg_control=cmsgu.control;
msg.msg_controllen=sizeof(cmsgu.control);
cmsg=cmsg_FIRSTHDR(&msg);
cmsg->cmsg_len=cmsg_len(sizeof(int));
cmsg->cmsg\U电平=SOL\U插座;
cmsg->cmsg\U类型=SCM\U权限;
printf(“通过fd%d\n”,fd);
*((int*)CMSG_DATA(CMSG))=fd;
}否则{
msg.msg_control=NULL;
msg.msg_controllen=0;
printf(“未通过fd\n”);
}
printf(“sendmsg:%d\n”,sock);
大小=sendmsg(sock和msg,0);
如果(尺寸<0)
perror(“sendmsg”);
返回大小;
}
int main(int argc,char*argv[]){
结构sockaddr_un addr;
char-buf[100];
int fd、cl、rc;
if((fd=socket(AF_UNIX,SOCK_STREAM,0))=-1){
perror(“套接字错误”);
出口(-1);
}
qDebug()我需要使用accept套接字“cl”而不是listen套接字“fd”。sock\u fd\u write(fd,(void*)“1”,1,1)
。看起来您正在向listen
套接字(fd
)而不是accept
套接字(cl
)写入。谢谢-请回答下面的问题,我将接受答案并投票表决。
#include <sys/socket.h>
#include <sys/un.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <QDebug>
char *socket_path = "/.socket";
ssize_t sock_fd_read(int sock, void *buf, ssize_t bufsize, int *fd) {
ssize_t size;
if (fd) {
struct msghdr msg;
struct iovec iov;
union {
struct cmsghdr cmsghdr;
char control[CMSG_SPACE(sizeof (int))];
} cmsgu;
struct cmsghdr *cmsg;
iov.iov_base = buf;
iov.iov_len = bufsize;
msg.msg_name = NULL;
msg.msg_namelen = 0;
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = cmsgu.control;
msg.msg_controllen = sizeof(cmsgu.control);
size = recvmsg (sock, &msg, 0);
if (size < 0) {
perror ("recvmsg");
exit(1);
}
cmsg = CMSG_FIRSTHDR(&msg);
if (cmsg && cmsg->cmsg_len == CMSG_LEN(sizeof(int))) {
if (cmsg->cmsg_level != SOL_SOCKET) {
fprintf (stderr, "invalid cmsg_level %d\n",
cmsg->cmsg_level);
exit(1);
}
if (cmsg->cmsg_type != SCM_RIGHTS) {
fprintf (stderr, "invalid cmsg_type %d\n",
cmsg->cmsg_type);
exit(1);
}
*fd = *((int *) CMSG_DATA(cmsg));
printf ("received fd %d\n", *fd);
} else
*fd = -1;
} else {
size = read (sock, buf, bufsize);
if (size < 0) {
perror("read");
exit(1);
}
}
return size;
}
int main(int argc, char *argv[]) {
struct sockaddr_un addr;
char buf[100];
int fd,rc;
if ( (fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
perror("socket error");
exit(-1);
}
qDebug() << "Socket connected";
memset(&addr, 0, sizeof(addr));
addr.sun_family = AF_UNIX;
strncpy(addr.sun_path, socket_path, sizeof(addr.sun_path)-1);
if (connect(fd, (struct sockaddr*)&addr, sizeof(addr)) == -1) {
perror("connect error");
exit(-1);
}
qDebug() << "Socket connected";
ssize_t size;
int fdRead;
while( (rc=read(STDIN_FILENO, buf, sizeof(buf))) > 0) {
qDebug() << "About to write";
if (write(fd, buf, rc) != rc) {
if (rc > 0) {
qDebug() << "Partial write";
size = sock_fd_read(fd, buf, sizeof(buf), &fdRead);
if (size <= 0) {
break;
}
printf("read %d\n", size);
if (fd != -1) {
write(fd, "hello, world\n", 13);
close(fd);
}
}
else {
perror("write error");
exit(-1);
}
}
}
return 0;
}