[net] Change meaning of SO_RCVBUF to set connect/accept buffer size

elks/include/linuxmt/net.h

@@ -5,7 +5,7 @@
 #include <linuxmt/socket.h>
 
 /* Number of protocols */
-#define NPROTO 3
+#define NPROTO 2
 
 #define SOCK_INODE(S)	((S)->inode)
 
@@ -27,14 +27,14 @@ struct socket {
     struct inode *inode;
     struct file *file;
 
-#if defined(CONFIG_UNIX)
+#ifdef CONFIG_UNIX
     struct socket *conn;
     struct socket *iconn;
     struct socket *next;
     void *data;
 #endif
 
-#if defined(CONFIG_INET)
+#ifdef CONFIG_INET
     sem_t sem;			/* one operation at a time per socket */
     int avail_data;		/* data available for reading from ktcp */
     int retval;			/* event return value from ktcp */
@@ -72,6 +72,7 @@ struct proto_ops {
 #define SF_RST_ON_CLOSE	(1 << 4) /* inet */
 #define SF_REUSE_ADDR	(1 << 5) /* inet */
 #define SF_CONNECT	(1 << 6) /* inet */
+#define SF_NOBUF        (1 << 7) /* inet */
 
 struct net_proto {
     const char *name;		/* Protocol name */

elks/include/linuxmt/socket.h

@@ -3,43 +3,39 @@
 
 #include <linuxmt/types.h>
 
-#define MAX_SOCK_ADDR 110  /* Sufficient size for AF_UNIX */
-
 struct sockaddr {
     unsigned short sa_family;
-    char sa_data [MAX_SOCK_ADDR];
+    char sa_data[20];       /* sufficient size for AF_UNIX sockaddr_un in un.h */
 };
 
-/* for setsockopt(2) */
-#define SOL_SOCKET	1
+/* setsockopt parameters */
+#define SOL_SOCKET      1
 
 /* careful: option names are close to internal SF_ options in net.h*/
-#define SO_REUSEADDR	2
-#define SO_RCVBUF	8		/* set TCP CB receive buffer size*/
-#define SO_LINGER	13		/* only implemented for l_linger = 0*/
+#define SO_REUSEADDR    2
+#define SO_RCVBUF       8               /* set TCP CB receive buffer size*/
+#define SO_LINGER       13              /* only implemented for l_linger = 0*/
 
 /* non-standard options */
-#define SO_LISTEN_BUFSIZ	128	/* suggested buffer size for listen to save mem*/
+#define SO_NOBUFFER     14              /* don't allocate rcv buffer (e.g. for listen) */
 
 struct linger {
         int             l_onoff;        /* Linger active                */
         int             l_linger;       /* How long to linger for       */
 };
 
-#define AF_INET	0
-#define AF_UNIX	1
+#define AF_INET 0
+#define AF_UNIX 1
 
-#define PF_INET	AF_INET
-#define PF_UNIX	AF_UNIX
+#define PF_INET AF_INET
+#define PF_UNIX AF_UNIX
 
 #define AF_LOCAL AF_UNIX
 #define PF_LOCAL PF_UNIX
 
-#define SOCK_STREAM     1	/* stream (connection) socket   */
-#define SOCK_DGRAM      2	/* datagram (conn.less) socket  */
-#define SOCK_RAW        3	/* raw socket                   */
-#define SOCK_RDM        4	/* reliably-delivered message   */
-#define SOCK_SEQPACKET  5	/* sequential packet socket     */
+#define SOCK_STREAM     1       /* stream (connection) socket   */
+#define SOCK_DGRAM      2       /* datagram (conn.less) socket  */
+#define SOCK_RAW        3       /* raw socket                   */
 
 #ifdef __KERNEL__
 struct proto_ops;

elks/include/linuxmt/tcpdev.h

@@ -8,8 +8,6 @@
 #include <linuxmt/in.h>
 #include <linuxmt/net.h>
 
-#define TCP_DEVICE_NAME	"tcpdev"
-
 /* should be equal to PTYOUTQ_SIZE and telnetd buffer size*/
 #define	TDB_WRITE_MAX		512	/* max data in tdb_write packet to ktcp*/
 
@@ -30,7 +28,7 @@
 struct tdb_release {
     unsigned char cmd;
     struct socket *sock;
-    int reset;
+    int reset;                      /* SO_LINGER -> SF_RST_ON_CLOSE */
 };
 
 struct tdb_accept {
@@ -49,7 +47,8 @@ struct tdb_listen {
 struct tdb_bind {
     unsigned char cmd;
     struct socket *sock;
-    int reuse_addr;
+    int reuse_addr;                 /* SO_REUSEADDR -> SF_REUSE_ADDR */
+    int no_buffer;                  /* SO_NOBUFFER -> SF_NOBUF */
     int rcv_bufsiz;
     struct sockaddr_in addr;
 };

elks/net/ipv4/af_inet.c

@@ -161,6 +161,7 @@ static int inet_bind(register struct socket *sock, struct sockaddr *addr,
     cmd->cmd = TDC_BIND;
     cmd->sock = sock;
     cmd->reuse_addr = sock->flags & SF_REUSE_ADDR;
+    cmd->no_buffer = sock->flags & SF_NOBUF;
     cmd->rcv_bufsiz = sock->rcv_bufsiz;
     memcpy_fromfs(&cmd->addr, addr, sockaddr_len);
 

elks/net/socket.c

@@ -47,9 +47,6 @@ static struct proto_ops *find_protocol_family(int family)
 
 static int check_addr_to_kernel(void *uaddr, size_t ulen)
 {
-    if (ulen > MAX_SOCK_ADDR)
-	return -EINVAL;
-
     if (ulen == 0)
 	return 0;
 
@@ -577,6 +574,11 @@ int sys_setsockopt(int fd, int level, int option_name, void *option_value,
 	flags = SF_REUSE_ADDR;
 	break;
 
+    case SO_NOBUFFER:
+	setoption = 1;
+	flags = SF_NOBUF;
+	break;
+
     default:
 	return -EINVAL;
     }

elkscmd/audio/audiorcv.c

@@ -308,9 +308,8 @@ int main(int argc, char **argv)
         perror("SO_REUSEADDR");
 
     /* set small listen buffer to save ktcp memory */
-    val = SO_LISTEN_BUFSIZ;
-    if (setsockopt(listen_sock, SOL_SOCKET, SO_RCVBUF, &val, sizeof(int)) < 0)
-        perror("SO_RCVBUF");
+    if (setsockopt(listen_sock, SOL_SOCKET, SO_NOBUFFER, NULL, 0) < 0)
+        perror("SO_NOBUFFER");
 
     memset(&localadr, 0, sizeof(localadr));
     localadr.sin_family = AF_INET;

elkscmd/inet/ftp.c

@@ -820,9 +820,8 @@ int do_active(int cmdfd) {
 	if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) < 0)
 		perror("SO_REUSEADDR");
 
-	i = SO_LISTEN_BUFSIZ;
-	if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &i, sizeof(i)) < 0) 
-		perror("SO_RCVBUF");
+	if (setsockopt(fd, SOL_SOCKET, SO_NOBUFFER, NULL, 0) < 0)
+		perror("SO_NOBUFFER");
 
 	bzero(&myaddr, sizeof(myaddr));
 	myaddr.sin_family = AF_INET;

elkscmd/inet/ftpd.c

@@ -494,12 +494,16 @@ int do_pasv(int *datafd, int epsv) {
 		perror("PASV socket");
 		return -1;
 	}
-
 	if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i)) < 0)
 		perror("PASV SO_REUSEADDR");
-	i = SO_LISTEN_BUFSIZ;
-	if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &i, sizeof(i)) < 0)
-                perror("PASV SO_RCVBUF");
+	if (setsockopt(fd, SOL_SOCKET, SO_NOBUFFER, NULL, 0) < 0)
+		perror("PASV SO_NOBUFFER");
+#if 1
+    /* test using 2/3 of normal 4390 byte buffer (=MTU-40 = 1460*2) */
+    int size = 2920;
+	if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &size, sizeof(size)) < 0)
+		perror("SO_RCVBUF");
+#endif
 
 	pasv.sin_family = AF_INET;
 	pasv.sin_addr.s_addr = htonl(INADDR_ANY);
@@ -700,9 +704,8 @@ int main(int argc, char **argv) {
 		perror("SO_REUSEADDR");
 
 	/* set small listen buffer to save ktcp memory */
-	ret = SO_LISTEN_BUFSIZ;
-	if (setsockopt(listenfd, SOL_SOCKET, SO_RCVBUF, &ret, sizeof(int)) < 0)
-		perror("SO_RCVBUF");
+	if (setsockopt(listenfd, SOL_SOCKET, SO_NOBUFFER, NULL, 0) < 0)
+		perror("SO_NOBUFFER");
 
 	servaddr.sin_family      = AF_INET;
 	servaddr.sin_addr.s_addr = htonl(INADDR_ANY);

elkscmd/inet/httpd.c

@@ -160,9 +160,8 @@ int main(int argc, char **argv)
         errmsg("http: SO_REUSEADDR");
 
     /* set small listen buffer to save ktcp memory */
-    ret = SO_LISTEN_BUFSIZ;
-    if (setsockopt(listen_sock, SOL_SOCKET, SO_RCVBUF, &ret, sizeof(int)) < 0)
-        errmsg("httpd: SO_RCVBUF");
+    if (setsockopt(listen_sock, SOL_SOCKET, SO_NOBUFFER, NULL, 0) < 0)
+        errmsg("httpd: SO_NOBUFFER");
 
     localadr.sin_family = AF_INET;
     localadr.sin_port = htons(DEF_PORT);

elkscmd/inet/telnetd.c

@@ -201,9 +201,8 @@ main(int argc, char **argv)
         perror("SO_REUSEADDR");
 
     /* set small listen buffer to save ktcp memory */
-    ret = SO_LISTEN_BUFSIZ;
-    if (setsockopt(sockfd, SOL_SOCKET, SO_RCVBUF, &ret, sizeof(int)) < 0)
-        perror("SO_RCVBUF");
+    if (setsockopt(sockfd, SOL_SOCKET, SO_NOBUFFER, NULL, 0) < 0)
+        perror("SO_NOBUFFER");
 
     memset(&addr_in, 0, sizeof(addr_in));
     addr_in.sin_family = AF_INET;

elkscmd/ktcp/tcp.c

@@ -189,8 +189,8 @@ static void tcp_listen(struct iptcp_s *iptcp, struct tcpcb_s *lcb)
     if (h->flags & TF_ACK)
 	debug_tcp("tcp: ACK in listen not implemented\n");
 
-    /* duplicate control block but with normal sized input buffer, SO_RCVBUF ignored for now */
-    n = tcpcb_clone(lcb, CB_NORMAL_BUFSIZ);    /* copy lcb into linked list*/
+    /* duplicate CB  with normal or SO_RCVBUF sized buffer */
+    n = tcpcb_clone(lcb, lcb->acc_size? lcb->acc_size: CB_NORMAL_BUFSIZ);
     if (!n)
 	return;		     /* no memory for new connection*/
     cb = &n->tcpcb;

elkscmd/ktcp/tcp.h

@@ -166,6 +166,7 @@ struct tcpcb_s {
 	__u16	buf_tail;
 	__u16	buf_used;		/* # valid bytes in buffer */
 	__u16	buf_size;		/* total buffer size */
+	__u16	acc_size;		/* accept CB buffer size from SO_RCVBUF */
 	__u8	buf_base[];
 };
 

elkscmd/ktcp/tcp_output.c

@@ -474,10 +474,14 @@ void tcp_output(struct tcpcb_s *cb)
     header_len = sizeof(tcphdr_t);
     if (cb->flags & TF_SYN) {
 	__u8 *options = th->options;
+	unsigned int mss = MTU - 40;
 
+	/* advertise segment we can actually accept */
+	if (cb->buf_size && mss > cb->buf_size)
+	    mss = cb->buf_size;
 	options[0] = TCP_OPT_MSS;
 	options[1] = TCP_OPT_MSS_LEN;		/* total options length (4)*/
-	*(__u16 *)(options + 2) = htons(MTU - 40);
+	*(__u16 *)(options + 2) = htons(mss);
 	header_len += TCP_OPT_MSS_LEN;
     }
 

elkscmd/ktcp/tcpdev.c

@@ -67,7 +67,7 @@ static void tcpdev_bind(void)
 {
     struct tdb_bind *db = (struct tdb_bind *)sbuf; /* read from sbuf*/
     struct tcpcb_list_s *n;
-    int size;
+    int size = 0;
     __u16 port;
     struct tdb_bind_ret bind_ret;
 
@@ -76,8 +76,12 @@ static void tcpdev_bind(void)
 	return;
     }
 
-    /* SO_RCVBUF currently only sets listen or connect buffer size, NOT accept size!*/
-    size = db->rcv_bufsiz? db->rcv_bufsiz: CB_NORMAL_BUFSIZ;
+    /*
+     * Use SO_NOBUFFER on listen sockets to save ktcp heap.
+     * Use SO_RCVBUF set connect or accept CB buffer size.
+     */
+    if (!db->no_buffer)
+	size = db->rcv_bufsiz? db->rcv_bufsiz: CB_NORMAL_BUFSIZ;
     n = tcpcb_new(size);
     if (n == NULL) {
 	retval_to_sock(db->sock,-ENOMEM);
@@ -117,6 +121,7 @@ static void tcpdev_bind(void)
     }
 
     n->tcpcb.sock = db->sock;
+    n->tcpcb.acc_size = db->rcv_bufsiz;
     if (db->addr.sin_addr.s_addr == htonl(0x7f000001))
         n->tcpcb.localaddr = db->addr.sin_addr.s_addr;
     else