net/iovec: add copy iterators for iovec[]

kernel/drivers/net/stack/include/rtnet_iovec.h

@@ -25,6 +25,8 @@
 
 #include <linux/uio.h>
 
+struct user_msghdr;
+struct rtdm_fd;
 
 /***
  *  rt_iovec_len
@@ -44,7 +46,13 @@ static inline size_t rt_iovec_len(const struct iovec *iov, int iovlen)
 extern void rt_memcpy_tokerneliovec(struct iovec *iov, unsigned char *kdata, int len);
 extern void rt_memcpy_fromkerneliovec(unsigned char *kdata, struct iovec *iov, int len);
 
+ssize_t rtnet_write_to_iov(struct rtdm_fd *fd,
+			   struct iovec *iov, int iovlen,
+			   const void *data, size_t len);
 
+ssize_t rtnet_read_from_iov(struct rtdm_fd *fd,
+			    struct iovec *iov, int iovlen,
+			    void *data, size_t len);
 #endif  /* __KERNEL__ */
 
 #endif  /* __RTNET_IOVEC_H_ */

kernel/drivers/net/stack/iovec.c

@@ -25,8 +25,9 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/string.h>
-
+#include <rtdm/driver.h>
 #include <rtnet_iovec.h>
+#include <rtnet_socket.h>
 
 
 /***
@@ -49,6 +50,7 @@ void rt_memcpy_tokerneliovec(struct iovec *iov, unsigned char *kdata, int len)
         iov++;
     }
 }
+EXPORT_SYMBOL_GPL(rt_memcpy_tokerneliovec);
 
 
 /***
@@ -71,7 +73,78 @@ void rt_memcpy_fromkerneliovec(unsigned char *kdata, struct iovec *iov,int len)
         iov++;
     }
 }
+EXPORT_SYMBOL_GPL(rt_memcpy_fromkerneliovec);
 
+ssize_t rtnet_write_to_iov(struct rtdm_fd *fd,
+			   struct iovec *iov, int iovlen,
+			   const void *data, size_t len)
+{
+	ssize_t ret = 0;
+	size_t nbytes;
+	int n;
 
-EXPORT_SYMBOL_GPL(rt_memcpy_tokerneliovec);
-EXPORT_SYMBOL_GPL(rt_memcpy_fromkerneliovec);
+	for (n = 0; len > 0 && n < iovlen; n++, iov++) {
+		if (iov->iov_len == 0)
+			continue;
+
+		nbytes = iov->iov_len;
+		if (nbytes > len)
+			nbytes = len;
+
+		ret = rtnet_put_arg(fd, iov->iov_base, data, nbytes);
+		if (ret)
+			break;
+	
+		len -= nbytes;
+		data += nbytes;
+		iov->iov_len -= nbytes;
+		iov->iov_base += nbytes;
+		ret += nbytes;
+		if (ret < 0) {
+			ret = -EINVAL;
+			break;
+		}
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(rtnet_write_to_iov);
+
+ssize_t rtnet_read_from_iov(struct rtdm_fd *fd,
+			    struct iovec *iov, int iovlen,
+			    void *data, size_t len)
+{
+	ssize_t ret = 0;
+	size_t nbytes;
+	int n;
+
+	for (n = 0; len > 0 && n < iovlen; n++, iov++) {
+		if (iov->iov_len == 0)
+			continue;
+
+		nbytes = iov->iov_len;
+		if (nbytes > len)
+			nbytes = len;
+
+		if (!rtdm_fd_is_user(fd))
+			memcpy(data, iov->iov_base, nbytes);
+		else {
+			ret = rtdm_copy_from_user(fd, data, iov->iov_base, nbytes);
+			if (ret)
+				break;
+		}
+	
+		len -= nbytes;
+		data += nbytes;
+		iov->iov_len -= nbytes;
+		iov->iov_base += nbytes;
+		ret += nbytes;
+		if (ret < 0) {
+			ret = -EINVAL;
+			break;
+		}
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(rtnet_read_from_iov);