kernel & libc: Add POSIX setsockopt syscall

This commit implements the POSIX setsockopt syscall so that user
programs may be able to configure sockets they have created.

Signed-off-by: Ian Moffett <ian@osmora.org>

4 files changed, 52 insertions, 0 deletions

diff --git a/sys/include/sys/socket.h b/sys/include/sys/socket.h
index 9224542..1a33108 100644
--- a/sys/include/sys/socket.h
+++ b/sys/include/sys/socket.h
@@ -184,6 +184,7 @@ scret_t sys_send(struct syscall_args *scargs);
 
 scret_t sys_recvmsg(struct syscall_args *scargs);
 scret_t sys_sendmsg(struct syscall_args *scargs);
+scret_t sys_setsockopt(struct syscall_args *scargs);
 #endif  /* _KERNEL */
 
 int socket(int domain, int type, int protocol);
diff --git a/sys/include/sys/syscall.h b/sys/include/sys/syscall.h
index 9798d80..f53db8f 100644
--- a/sys/include/sys/syscall.h
+++ b/sys/include/sys/syscall.h
@@ -66,6 +66,7 @@
 #define SYS_sendmsg 25
 #define SYS_recvmsg 26
 #define SYS_connect 27
+#define SYS_setsockopt 28
 
 #if defined(_KERNEL)
 /* Syscall return value and arg type */
diff --git a/sys/kern/kern_socket.c b/sys/kern/kern_socket.c
index 0b10d0c..edaf32d 100644
--- a/sys/kern/kern_socket.c
+++ b/sys/kern/kern_socket.c
@@ -953,6 +953,55 @@ sys_connect(struct syscall_args *scargs)
     return connect(sockfd, sockaddr, len);
 }
 
+/*
+ * POSIX setsockopt(3) syscall
+ *
+ * arg0: sockfd
+ * arg1: level
+ * arg2: name
+ * arg3: data
+ * arg4: len
+ */
+scret_t
+sys_setsockopt(struct syscall_args *scargs)
+{
+    int sockfd = scargs->arg0;
+    int level = scargs->arg1;
+    int name = scargs->arg2;
+    void *u_data = (void *)scargs->arg3;
+    socklen_t len = scargs->arg4;
+    void *data;
+    size_t exp_len;
+    int retval;
+
+    /* Verify that the name is correct */
+    if (name >= _SO_MAX) {
+        return -EINVAL;
+    }
+
+    /* Clamp length as needed */
+    exp_len = sockopt_lentab[name];
+    if (len > exp_len) {
+        len = exp_len;
+    }
+
+    data = dynalloc(len);
+    if (data == NULL) {
+        return -ENOMEM;
+    }
+
+    /* Grab data from userland */
+    retval = copyin(u_data, data, len);
+    if (retval < 0) {
+        dynfree(data);
+        return retval;
+    }
+
+    retval = setsockopt(sockfd, level, name, data, len);
+    dynfree(data);
+    return retval;
+}
+
 static struct vops socket_vops = {
     .read = NULL,
     .write = NULL,
diff --git a/sys/kern/kern_syscall.c b/sys/kern/kern_syscall.c
index 576b7aa..ba70b12 100644
--- a/sys/kern/kern_syscall.c
+++ b/sys/kern/kern_syscall.c
@@ -68,6 +68,7 @@ scret_t(*g_sctab[])(struct syscall_args *) = {
     sys_sendmsg, /* SYS_sendmsg */
     sys_recvmsg, /* SYS_recvmsg */
     sys_connect, /* SYS_connect */
+    sys_setsockopt,  /* SYS_setsockopt */
 };
 
 const size_t MAX_SYSCALLS = NELEM(g_sctab);