Implement SO_NOSIGPIPE option for sockets. This allows one to request that

an EPIPE error return not generate SIGPIPE on sockets.

Submitted by: lioux
Inspired by: Darwin

3 files changed, 6 insertions, 2 deletions

diff --git a/sys/kern/sys_generic.c b/sys/kern/sys_generic.c
index bec5cca..1bdd913 100644
--- a/sys/kern/sys_generic.c
+++ b/sys/kern/sys_generic.c
@@ -420,7 +420,8 @@ dofilewrite(td, fp, fd, buf, nbyte, offset, flags)
 		if (auio.uio_resid != cnt && (error == ERESTART ||
 		    error == EINTR || error == EWOULDBLOCK))
 			error = 0;
-		if (error == EPIPE) {
+		/* Socket layer is responsible for issuing SIGPIPE. */
+		if (error == EPIPE && fp->f_type != DTYPE_SOCKET) {
 			PROC_LOCK(td->td_proc);
 			psignal(td->td_proc, SIGPIPE);
 			PROC_UNLOCK(td->td_proc);
diff --git a/sys/kern/uipc_socket.c b/sys/kern/uipc_socket.c
index 6458ce0..2b9e0be 100644
--- a/sys/kern/uipc_socket.c
+++ b/sys/kern/uipc_socket.c
@@ -1179,6 +1179,7 @@ sosetopt(so, sopt)
 		case SO_REUSEPORT:
 		case SO_OOBINLINE:
 		case SO_TIMESTAMP:
+		case SO_NOSIGPIPE:
 			error = sooptcopyin(sopt, &optval, sizeof optval,
 					    sizeof optval);
 			if (error)
@@ -1362,6 +1363,7 @@ sogetopt(so, sopt)
 		case SO_BROADCAST:
 		case SO_OOBINLINE:
 		case SO_TIMESTAMP:
+		case SO_NOSIGPIPE:
 			optval = so->so_options & sopt->sopt_name;
 integer:
 			error = sooptcopyout(sopt, &optval, sizeof optval);
diff --git a/sys/kern/uipc_syscalls.c b/sys/kern/uipc_syscalls.c
index b44e644..60e5719 100644
--- a/sys/kern/uipc_syscalls.c
+++ b/sys/kern/uipc_syscalls.c
@@ -649,7 +649,8 @@ sendit(td, s, mp, flags)
 		if (auio.uio_resid != len && (error == ERESTART ||
 		    error == EINTR || error == EWOULDBLOCK))
 			error = 0;
-		if (error == EPIPE) {
+		/* Generation of SIGPIPE can be controlled per socket */
+		if (error == EPIPE && !(so->so_options & SO_NOSIGPIPE)) {
 			PROC_LOCK(td->td_proc);
 			psignal(td->td_proc, SIGPIPE);
 			PROC_UNLOCK(td->td_proc);