ipc: socket creation with socket()

src/include/kernel/socket.h

@@ -39,8 +39,8 @@ struct sockaddr_un {
 
 /* socket-specific I/O descriptor (see io.h) */
 typedef struct {
-    struct sockaddr socket;
-    int backlog;
+    struct sockaddr address;
+    int type, protocol, backlog;
     int inboundCount, outboundCount;
     void **inbound, **outbound;
 } SocketDescriptor;

src/ipc/sockinit.c

@@ -0,0 +1,52 @@
+/*
+ * lux - a lightweight unix-like operating system
+ * Omar Elghoul, 2024
+ * 
+ * Core Microkernel
+ */
+
+/* Socket Initialization Functions */
+/* socket(), bind(), and close() for sockets are implemented here */
+
+/* I tried my best to follow The Base Specification Issue 8 */
+
+#include <errno.h>
+#include <stdlib.h>
+#include <kernel/socket.h>
+#include <kernel/io.h>
+#include <kernel/sched.h>
+
+/* socket(): opens a communication socket
+ * params: t - calling thread, NULL for kernel threads
+ * params: domain - socket domain/family
+ * params: type - type of socket (connection, datagram, etc)
+ * params: protocol - protocol implementing "type" on "domain", zero for default
+ * returns: positive socket descriptor on success, negative error code on fail
+ */
+
+int socket(Thread *t, int domain, int type, int protocol) {
+    Process *p;
+    if(t) p = getProcess(t->pid);
+    else p = getProcess(getPid());
+
+    if(!p) return -ESRCH;
+    if(p->iodCount == MAX_IO_DESCRIPTORS) return -EMFILE;
+
+    IODescriptor *iod = NULL;       // open I/O descriptor
+    int sd = openIO(p, (void **) &iod);
+    if(sd < 0 || !iod) return sd;
+
+    iod->type = IO_SOCKET;
+    iod->data = calloc(1, sizeof(SocketDescriptor));
+    if(!iod->data) {
+        closeIO(p, iod);
+    }
+
+    // set up the socket family for now
+    SocketDescriptor *sock = (SocketDescriptor *)iod->data;
+    sock->address.sa_family = domain;
+    sock->type = type;
+    sock->protocol = protocol;
+
+    return sd;
+}