Mike Waychison
2010-Jun-07 23:30 UTC
[klibc] [PATCH] Add ancillary data structures and macros to sys/socket.h
It turns out that all the CMSG_* structures and macros are hidden behind
__KERNEL__ in current kernel.org kernels. Expose these macros in sys/socket.h
for the time being to make them available.
Signed-off-by: Mike Waychison <mikew at google.com>
---
usr/include/sys/socket.h | 80 ++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 80 insertions(+), 0 deletions(-)
diff --git a/usr/include/sys/socket.h b/usr/include/sys/socket.h
index c69caaf..53b7ea4 100644
--- a/usr/include/sys/socket.h
+++ b/usr/include/sys/socket.h
@@ -159,6 +159,86 @@ struct msghdr {
unsigned msg_flags;
};
+/* Ancillary data structures and cmsg macros are also hidden under __KERNEL__
*/
+#ifndef CMSG_FIRSTHDR
+/*
+ * POSIX 1003.1g - ancillary data object information
+ * Ancillary data consits of a sequence of pairs of
+ * (cmsghdr, cmsg_data[])
+ */
+
+struct cmsghdr {
+ __kernel_size_t cmsg_len; /* data byte count, including hdr */
+ int cmsg_level; /* originating protocol */
+ int cmsg_type; /* protocol-specific type */
+};
+
+/*
+ * Ancilliary data object information MACROS
+ * Table 5-14 of POSIX 1003.1g
+ */
+
+#define __CMSG_NXTHDR(ctl, len, cmsg) __cmsg_nxthdr((ctl),(len),(cmsg))
+#define CMSG_NXTHDR(mhdr, cmsg) cmsg_nxthdr((mhdr), (cmsg))
+
+#define CMSG_ALIGN(len) ( ((len)+sizeof(long)-1) & ~(sizeof(long)-1) )
+
+#define CMSG_DATA(cmsg) ((void *)((char *)(cmsg) + CMSG_ALIGN(sizeof(struct
cmsghdr))))
+#define CMSG_SPACE(len) (CMSG_ALIGN(sizeof(struct cmsghdr)) + CMSG_ALIGN(len))
+#define CMSG_LEN(len) (CMSG_ALIGN(sizeof(struct cmsghdr)) + (len))
+
+#define __CMSG_FIRSTHDR(ctl,len) ((len) >= sizeof(struct cmsghdr) ? \
+ (struct cmsghdr *)(ctl) : \
+ (struct cmsghdr *)NULL)
+#define CMSG_FIRSTHDR(msg) __CMSG_FIRSTHDR((msg)->msg_control,
(msg)->msg_controllen)
+#define CMSG_OK(mhdr, cmsg) ((cmsg)->cmsg_len >= sizeof(struct cmsghdr)
&& \
+ (cmsg)->cmsg_len <= (unsigned long) \
+ ((mhdr)->msg_controllen - \
+ ((char *)(cmsg) - (char *)(mhdr)->msg_control)))
+
+/*
+ * Get the next cmsg header
+ *
+ * PLEASE, do not touch this function. If you think, that it is
+ * incorrect, grep kernel sources and think about consequences
+ * before trying to improve it.
+ *
+ * Now it always returns valid, not truncated ancillary object
+ * HEADER. But caller still MUST check, that cmsg->cmsg_len is
+ * inside range, given by msg->msg_controllen before using
+ * ancillary object DATA. --ANK (980731)
+ */
+
+static inline struct cmsghdr * __cmsg_nxthdr(void *__ctl, __kernel_size_t
__size,
+ struct cmsghdr *__cmsg)
+{
+ struct cmsghdr * __ptr;
+
+ __ptr = (struct cmsghdr*)(((unsigned char *) __cmsg) +
CMSG_ALIGN(__cmsg->cmsg_len));
+ if ((unsigned long)((char*)(__ptr+1) - (char *) __ctl) > __size)
+ return (struct cmsghdr *)0;
+
+ return __ptr;
+}
+
+static inline struct cmsghdr * cmsg_nxthdr (struct msghdr *__msg, struct
cmsghdr *__cmsg)
+{
+ return __cmsg_nxthdr(__msg->msg_control, __msg->msg_controllen, __cmsg);
+}
+
+/* "Socket"-level control message types: */
+
+#define SCM_RIGHTS 0x01 /* rw: access rights (array of int) */
+#define SCM_CREDENTIALS 0x02 /* rw: struct ucred */
+#define SCM_SECURITY 0x03 /* rw: security label */
+
+struct ucred {
+ __u32 pid;
+ __u32 uid;
+ __u32 gid;
+};
+#endif /* CMSG_FIRSTHDR */
+
__extern int socket(int, int, int);
__extern int bind(int, struct sockaddr *, int);
--
1.7.0.1