about summary refs log tree commit diff
path: root/sysdeps/unix/sysv/linux/socketbits.h
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/unix/sysv/linux/socketbits.h')
-rw-r--r--sysdeps/unix/sysv/linux/socketbits.h41
1 files changed, 41 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/socketbits.h b/sysdeps/unix/sysv/linux/socketbits.h
index 1cf44b4347..91deb6c815 100644
--- a/sysdeps/unix/sysv/linux/socketbits.h
+++ b/sysdeps/unix/sysv/linux/socketbits.h
@@ -126,6 +126,47 @@ struct msghdr
     int msg_flags;		/* Flags on received message.  */
   };
 
+/* Structure used for storage of ancillary data object information.  */
+struct cmsghdr
+  {
+    int cmsg_len;		/* Length of data in cmsg_data plus length
+				   of cmsghdr structure.  */
+    /* XXX Should be type `size_t' according to POSIX.1g.  */
+    int cmsg_level;		/* Originating protocol.  */
+    int cmsg_type;		/* Protocol specific type.  */
+    unsigned char __cmsg_data[0]; /* Ancillary data.  */
+  };
+
+/* Ancillary data object manipulation macros.  */
+#define CMSG_DATA(cmsg) ((cmsg)->__cmsg_data)
+#define CMSG_NXTHDR(mhdr, cmsg) __cmsg_nxthdr (mhdr, cmsg)
+#define CMSG_FIRSTHDR(mhdr) (mhdr) \
+  ((size_t) (mhdr)->msg_controllen >= sizeof (struct cmsghdr)			      \
+   ? (struct cmsghdr *) (mhdr)->msg_control : (struct cmsghdr *) NULL)
+
+
+#ifndef _EXTERN_INLINE
+# define _EXTERN_INLINE extern __inline
+#endif
+extern struct cmsghdr *__cmsg_nxthdr __P ((struct msghdr *__mhdr,
+					   struct cmsghdr *__cmsg));
+_EXTERN_INLINE struct cmsghdr *
+__cmsg_nxthdr (struct msghdr *__mhdr, struct cmsghdr *__cmsg)
+{
+  unsigned char *__p;
+
+  if ((size_t) __cmsg->cmsg_len < sizeof (struct cmsghdr))
+    /* The kernel header does this so there may be a reason.  */
+    return NULL;
+
+  __p = (((unsigned char *) __cmsg)
+	 + ((__cmsg->cmsg_len + sizeof (long int) - 1) & ~sizeof (long int)));
+  if (__p >= (unsigned char *) __mhdr->msg_control + __mhdr->msg_controllen)
+    /* No more entries.  */
+    return NULL;
+  return (struct cmsghdr *) __p;
+}
+
 
 /* Get socket manipulation related informations from kernel headers.  */
 #include <asm/socket.h>