我正在开发一个使用 UNIX 域数据报套接字进行 IPC 的程序。一半的时间它工作正常,但另一半它返回“无效的参数”。我已经确认这不应该是由于套接字路径重用错误造成的,在套接字上设置了 SO_REUSEADDR,并且即使删除了套接字路径中的任何残留文件,也会发生错误。为什么会出现这种情况?代码如下:
服务器
/* receive data from the client and return a structure containing operation information and argument */
int handle_input(int server_socket, module *module_registry) {
input client_input; // operation and argument sent from client
struct sockaddr *client_address;
unsigned int cl_address_len;
if(recvfrom(server_socket, &client_input, sizeof(input), 0, client_address, &cl_address_len) < 0) {
fprintf(stderr, "failed to receive from datagram socket\n");
perror("guru meditation");
return 0;
}
/* parse input ... */
}
客户端
int main(int argc, char **argv) {
/* parse input ... */
/* initialize client socket and addressing information */
if((client_socket = socket(AF_UNIX, SOCK_DGRAM, 0)) < 0) {
fprintf(stderr, "failed to bind client socket\n");
exit(1);
}
/* initialize server socket addressing information */
memset(&server_addr, 0, sizeof(struct sockaddr_un));
server_addr.sun_family = AF_UNIX;
snprintf(server_addr.sun_path, sizeof server_addr.sun_path, "%s", SOCK_PATH);
if(sendto(client_socket, &client_input, sizeof(input), 0, (struct sockaddr *)&server_addr, sizeof(struct sockaddr_un))
fprintf(stderr, "failed to send message to daemon\n");
exit(1);
}
exit(0);
}
最佳答案
Half the time it works fine, but the other half it returns "Invalid argument"
这是因为 cl_address_len
需要使用地址缓冲区的大小进行初始化,但它包含一个不确定的值。
您需要进行以下更改:
struct sockaddr_un client_address;
socklen_t cl_address_len = sizeof client_address;
if(recvfrom(server_socket, &client_input, sizeof(input), 0, (struct sockaddr*)&client_address, &cl_address_len) < 0) {
关于c - 为什么 UNIX 域数据报套接字的 recvfrom() 返回无效参数?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/59778239/