Implement networking syscalls, ftp and wget apps (AI)

apps/libc/syscalls.h

@@ -26,6 +26,11 @@ typedef int int32_t;
 #define SYS_READDIR 10
 #define SYS_OPEN    11
 #define SYS_CLOSE   12
+#define SYS_SOCKET  13
+#define SYS_CONNECT 14
+#define SYS_SEND    15
+#define SYS_RECV    16
+#define SYS_SOCKSTATE 17
 
 static inline int32_t syscall0(int num) {
     int32_t ret;
@@ -124,6 +129,71 @@ static inline int32_t close(int32_t fd) {
     return syscall1(SYS_CLOSE, (uint32_t)fd);
 }
 
+/* ================================================================
+ * Networking system calls
+ * ================================================================ */
+
+/** Socket type constants. */
+#define SOCK_TCP 0
+#define SOCK_UDP 1
+
+/** TCP state constants (match kernel tcp.h). */
+#define TCP_STATE_CLOSED       0
+#define TCP_STATE_SYN_SENT     2
+#define TCP_STATE_ESTABLISHED  4
+#define TCP_STATE_CLOSE_WAIT   7
+
+/**
+ * Create a network socket.
+ * @param type SOCK_TCP (0) or SOCK_UDP (1).
+ * @return Socket descriptor (>= 0) or -1 on failure.
+ */
+static inline int32_t socket(uint32_t type) {
+    return syscall1(SYS_SOCKET, type);
+}
+
+/**
+ * Connect a TCP socket to a remote host.
+ * @param sockfd Socket descriptor.
+ * @param ip     Remote IP address (host byte order).
+ * @param port   Remote port (host byte order).
+ * @return 0 on success (SYN sent), -1 on failure.
+ */
+static inline int32_t connect(int32_t sockfd, uint32_t ip, uint32_t port) {
+    return syscall3(SYS_CONNECT, (uint32_t)sockfd, ip, port);
+}
+
+/**
+ * Send data on a connected socket.
+ * @param sockfd Socket descriptor.
+ * @param buf    Data buffer.
+ * @param len    Data length.
+ * @return Bytes sent, or -1 on failure.
+ */
+static inline int32_t net_send(int32_t sockfd, const void *buf, uint32_t len) {
+    return syscall3(SYS_SEND, (uint32_t)sockfd, (uint32_t)buf, len);
+}
+
+/**
+ * Receive data from a connected socket (non-blocking).
+ * @param sockfd  Socket descriptor.
+ * @param buf     Buffer.
+ * @param bufsize Buffer size.
+ * @return Bytes received, 0 if no data, -1 on error/closed.
+ */
+static inline int32_t net_recv(int32_t sockfd, void *buf, uint32_t bufsize) {
+    return syscall3(SYS_RECV, (uint32_t)sockfd, (uint32_t)buf, bufsize);
+}
+
+/**
+ * Get the state of a TCP socket.
+ * @param sockfd Socket descriptor.
+ * @return TCP state constant, or -1.
+ */
+static inline int32_t sockstate(int32_t sockfd) {
+    return syscall1(SYS_SOCKSTATE, (uint32_t)sockfd);
+}
+
 /* Basic string operations for user-space */
 static inline uint32_t strlen(const char *s) {
     uint32_t len = 0;