From: mbuhl <mbuhl@openbsd.org>
Date: Sat, 3 Sep 2022 12:33:44 +0000 (+0000)
Subject: add the sendmmsg syscall that allows sending multiple msghdrs at
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=94bc6e282f5b07d1de39ef73346b4eb06b2a5ea6;p=openbsd

add the sendmmsg syscall that allows sending multiple msghdrs at
once. libc, man page, and regress parts to come.
With input from jca@, bluhm@.
OK bluhm@
---

diff --git a/sys/kern/init_sysent.c b/sys/kern/init_sysent.c
index 59dd3aded35..7e2cc3661d1 100644
--- a/sys/kern/init_sysent.c
+++ b/sys/kern/init_sysent.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: init_sysent.c,v 1.245 2022/09/02 13:23:33 mbuhl Exp $	*/
+/*	$OpenBSD: init_sysent.c,v 1.246 2022/09/03 12:33:44 mbuhl Exp $	*/
 
 /*
  * System call switch table.
@@ -266,8 +266,8 @@ const struct sysent sysent[] = {
 	    sys___realpath },			/* 115 = __realpath */
 	{ 5, s(struct sys_recvmmsg_args), SY_NOLOCK | 0,
 	    sys_recvmmsg },			/* 116 = recvmmsg */
-	{ 0, 0, 0,
-	    sys_nosys },			/* 117 = unimplemented sendmmsg */
+	{ 4, s(struct sys_sendmmsg_args), SY_NOLOCK | 0,
+	    sys_sendmmsg },			/* 117 = sendmmsg */
 	{ 5, s(struct sys_getsockopt_args), 0,
 	    sys_getsockopt },			/* 118 = getsockopt */
 	{ 3, s(struct sys_thrkill_args), 0,
diff --git a/sys/kern/syscalls.c b/sys/kern/syscalls.c
index 9f3b973e005..2cddcb6a538 100644
--- a/sys/kern/syscalls.c
+++ b/sys/kern/syscalls.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: syscalls.c,v 1.243 2022/09/02 13:23:33 mbuhl Exp $	*/
+/*	$OpenBSD: syscalls.c,v 1.244 2022/09/03 12:33:44 mbuhl Exp $	*/
 
 /*
  * System call names.
@@ -137,7 +137,7 @@ const char *const syscallnames[] = {
 	"unveil",			/* 114 = unveil */
 	"__realpath",			/* 115 = __realpath */
 	"recvmmsg",			/* 116 = recvmmsg */
-	"#117 (unimplemented sendmmsg)",		/* 117 = unimplemented sendmmsg */
+	"sendmmsg",			/* 117 = sendmmsg */
 	"getsockopt",			/* 118 = getsockopt */
 	"thrkill",			/* 119 = thrkill */
 	"readv",			/* 120 = readv */
diff --git a/sys/kern/syscalls.master b/sys/kern/syscalls.master
index eaf34dfabfe..9d88bf30dc1 100644
--- a/sys/kern/syscalls.master
+++ b/sys/kern/syscalls.master
@@ -1,4 +1,4 @@
-;	$OpenBSD: syscalls.master,v 1.230 2022/09/02 13:18:06 mbuhl Exp $
+;	$OpenBSD: syscalls.master,v 1.231 2022/09/03 12:33:44 mbuhl Exp $
 ;	$NetBSD: syscalls.master,v 1.32 1996/04/23 10:24:21 mycroft Exp $
 
 ;	@(#)syscalls.master	8.2 (Berkeley) 1/13/94
@@ -247,7 +247,9 @@
 116	STD NOLOCK	{ int sys_recvmmsg(int s, struct mmsghdr *mmsg, \
 			    unsigned int vlen, unsigned int flags, \
 			    struct timespec *timeout); }
-117	UNIMPL		sendmmsg
+117	STD NOLOCK	{ int sys_sendmmsg(int s,  \
+			    struct mmsghdr *mmsg, unsigned int vlen, \
+			    unsigned int flags); }
 118	STD		{ int sys_getsockopt(int s, int level, int name, \
 			    void *val, socklen_t *avalsize); }
 119	STD		{ int sys_thrkill(pid_t tid, int signum, void *tcb); }
diff --git a/sys/kern/uipc_syscalls.c b/sys/kern/uipc_syscalls.c
index b68e8534048..02a36683b9f 100644
--- a/sys/kern/uipc_syscalls.c
+++ b/sys/kern/uipc_syscalls.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uipc_syscalls.c,v 1.202 2022/09/02 13:18:06 mbuhl Exp $	*/
+/*	$OpenBSD: uipc_syscalls.c,v 1.203 2022/09/03 12:33:44 mbuhl Exp $	*/
 /*	$NetBSD: uipc_syscalls.c,v 1.19 1996/02/09 19:00:48 christos Exp $	*/
 
 /*
@@ -605,6 +605,92 @@ done:
 	return (error);
 }
 
+int
+sys_sendmmsg(struct proc *p, void *v, register_t *retval)
+{
+	struct sys_sendmmsg_args /* {
+		syscallarg(int)			s;
+		syscallarg(struct mmsghdr *)	mmsg;
+		syscallarg(unsigned int)	vlen;
+		syscallarg(unsigned int)	flags;
+	} */ *uap = v;
+	struct mmsghdr mmsg, *mmsgp;
+	struct iovec aiov[UIO_SMALLIOV], *iov = aiov, *uiov;
+	size_t iovlen = UIO_SMALLIOV;
+	register_t retsnd;
+	unsigned int vlen, dgrams;
+	int error = 0;
+
+	/* Arbitrarily capped at 1024 datagrams. */
+	vlen = SCARG(uap, vlen);
+	if (vlen > 1024)
+		vlen = 1024;
+
+	mmsgp = SCARG(uap, mmsg);
+	for (dgrams = 0; dgrams < vlen; dgrams++) {
+		error = copyin(&mmsgp[dgrams], &mmsg, sizeof(mmsg));
+		if (error)
+			break;
+
+#ifdef KTRACE
+		if (KTRPOINT(p, KTR_STRUCT))
+			ktrmmsghdr(p, &mmsg);
+#endif
+
+		if (mmsg.msg_hdr.msg_iovlen > IOV_MAX) {
+			error = EMSGSIZE;
+			break;
+		}
+
+		if (mmsg.msg_hdr.msg_iovlen > iovlen) {
+			if (iov != aiov)
+				free(iov, M_IOV, iovlen *
+				    sizeof(struct iovec));
+
+			iovlen = mmsg.msg_hdr.msg_iovlen;
+			iov = mallocarray(iovlen, sizeof(struct iovec),
+			    M_IOV, M_WAITOK);
+		}
+
+		if (mmsg.msg_hdr.msg_iovlen > 0) {
+			error = copyin(mmsg.msg_hdr.msg_iov, iov,
+			    mmsg.msg_hdr.msg_iovlen * sizeof(struct iovec));
+			if (error)
+				break;
+		}
+
+#ifdef KTRACE
+		if (mmsg.msg_hdr.msg_iovlen && KTRPOINT(p, KTR_STRUCT))
+			ktriovec(p, iov, mmsg.msg_hdr.msg_iovlen);
+#endif
+
+		uiov = mmsg.msg_hdr.msg_iov;
+		mmsg.msg_hdr.msg_iov = iov;
+		mmsg.msg_hdr.msg_flags = 0;
+
+		error = sendit(p, SCARG(uap, s), &mmsg.msg_hdr,
+		    SCARG(uap, flags), &retsnd);
+		if (error)
+			break;
+
+		mmsg.msg_hdr.msg_iov = uiov;
+		mmsg.msg_len = retsnd;
+
+		error = copyout(&mmsg, &mmsgp[dgrams], sizeof(mmsg));
+		if (error)
+			break;
+	}
+
+	if (iov != aiov)
+		free(iov, M_IOV, sizeof(struct iovec) * iovlen);
+
+	*retval = dgrams;
+
+	if (dgrams)
+		return 0;
+	return error;
+}
+
 int
 sendit(struct proc *p, int s, struct msghdr *mp, int flags, register_t *retsize)
 {
diff --git a/sys/sys/socket.h b/sys/sys/socket.h
index 35758827b30..06def618354 100644
--- a/sys/sys/socket.h
+++ b/sys/sys/socket.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: socket.h,v 1.103 2022/09/02 13:18:07 mbuhl Exp $	*/
+/*	$OpenBSD: socket.h,v 1.104 2022/09/03 12:33:45 mbuhl Exp $	*/
 /*	$NetBSD: socket.h,v 1.14 1996/02/09 18:25:36 christos Exp $	*/
 
 /*
@@ -579,6 +579,7 @@ ssize_t	send(int, const void *, size_t, int);
 ssize_t	sendto(int, const void *,
 	    size_t, int, const struct sockaddr *, socklen_t);
 ssize_t	sendmsg(int, const struct msghdr *, int);
+int	sendmmsg(int, struct mmsghdr *, unsigned int, unsigned int);
 int	setsockopt(int, int, int, const void *, socklen_t);
 int	shutdown(int, int);
 int	sockatmark(int);
diff --git a/sys/sys/syscall.h b/sys/sys/syscall.h
index 3965289efb4..c2ad6f36256 100644
--- a/sys/sys/syscall.h
+++ b/sys/sys/syscall.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: syscall.h,v 1.242 2022/09/02 13:23:33 mbuhl Exp $	*/
+/*	$OpenBSD: syscall.h,v 1.243 2022/09/03 12:33:45 mbuhl Exp $	*/
 
 /*
  * System call numbers.
@@ -355,6 +355,9 @@
 /* syscall: "recvmmsg" ret: "int" args: "int" "struct mmsghdr *" "unsigned int" "unsigned int" "struct timespec *" */
 #define	SYS_recvmmsg	116
 
+/* syscall: "sendmmsg" ret: "int" args: "int" "struct mmsghdr *" "unsigned int" "unsigned int" */
+#define	SYS_sendmmsg	117
+
 /* syscall: "getsockopt" ret: "int" args: "int" "int" "int" "void *" "socklen_t *" */
 #define	SYS_getsockopt	118
 
diff --git a/sys/sys/syscallargs.h b/sys/sys/syscallargs.h
index c0559a0502f..5b20dce89e3 100644
--- a/sys/sys/syscallargs.h
+++ b/sys/sys/syscallargs.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: syscallargs.h,v 1.245 2022/09/02 13:23:33 mbuhl Exp $	*/
+/*	$OpenBSD: syscallargs.h,v 1.246 2022/09/03 12:33:45 mbuhl Exp $	*/
 
 /*
  * System call argument lists.
@@ -603,6 +603,13 @@ struct sys_recvmmsg_args {
 	syscallarg(struct timespec *) timeout;
 };
 
+struct sys_sendmmsg_args {
+	syscallarg(int) s;
+	syscallarg(struct mmsghdr *) mmsg;
+	syscallarg(unsigned int) vlen;
+	syscallarg(unsigned int) flags;
+};
+
 struct sys_getsockopt_args {
 	syscallarg(int) s;
 	syscallarg(int) level;
@@ -1311,6 +1318,7 @@ int	sys_sendsyslog(struct proc *, void *, register_t *);
 int	sys_unveil(struct proc *, void *, register_t *);
 int	sys___realpath(struct proc *, void *, register_t *);
 int	sys_recvmmsg(struct proc *, void *, register_t *);
+int	sys_sendmmsg(struct proc *, void *, register_t *);
 int	sys_getsockopt(struct proc *, void *, register_t *);
 int	sys_thrkill(struct proc *, void *, register_t *);
 int	sys_readv(struct proc *, void *, register_t *);