This adds a new API to do multishot recvmsg. This is more complicated than
multishot recv as it requires handling a well known data layout copied by
the kernel.
Signed-off-by: Dylan Yudaken <dylany@xxxxxx>
---
src/include/liburing.h | 59 +++++++++++++++++++++++++++++++++
src/include/liburing/io_uring.h | 7 ++++
2 files changed, 66 insertions(+)
diff --git a/src/include/liburing.h b/src/include/liburing.h
index d35bfa9..3f18bd2 100644
--- a/src/include/liburing.h
+++ b/src/include/liburing.h
@@ -419,6 +419,13 @@ static inline void io_uring_prep_recvmsg(struct io_uring_sqe *sqe, int fd,
sqe->msg_flags = flags;
}
+static inline void io_uring_prep_recvmsg_multishot(struct io_uring_sqe *sqe, int fd,
+ struct msghdr *msg, unsigned flags)
+{
+ io_uring_prep_recvmsg(sqe, fd, msg, flags);
+ sqe->ioprio |= IORING_RECV_MULTISHOT;
+}
+
static inline void io_uring_prep_sendmsg(struct io_uring_sqe *sqe, int fd,
const struct msghdr *msg,
unsigned flags)
@@ -685,6 +692,58 @@ static inline void io_uring_prep_recv_multishot(struct io_uring_sqe *sqe,
sqe->ioprio |= IORING_RECV_MULTISHOT;
}
+static inline struct io_uring_recvmsg_out *io_uring_recvmsg_validate(
+ void *buf, int buf_len, struct msghdr *m)
+{
+ struct io_uring_recvmsg_out *ret;
+ size_t header = m->msg_controllen + m->msg_namelen + sizeof(struct io_uring_recvmsg_out);
+
+ if (buf_len < header)
+ return NULL;
+ ret = (struct io_uring_recvmsg_out *)buf;
+ if (buf_len < header + ret->payloadlen)
+ return NULL;
+ return ret;
+}
+
+static inline void *io_uring_recvmsg_name(struct io_uring_recvmsg_out *o)
+{
+ return (void*)&o[1];
+}
+
+static inline struct cmsghdr *io_uring_recvmsg_cmsg_firsthdr(struct io_uring_recvmsg_out *o,
+ struct msghdr *m)
+{
+ if (o->controllen < sizeof(struct cmsghdr))
+ return NULL;
+ return (struct cmsghdr *)((unsigned char*)io_uring_recvmsg_name(o) + m->msg_namelen);
+}
+
+static inline void *io_uring_recvmsg_payload(struct io_uring_recvmsg_out *o,
+ struct msghdr *m)
+{
+ return (void*)((unsigned char*)io_uring_recvmsg_name(o) + m->msg_namelen + m->msg_controllen);
+}
+
+static inline struct cmsghdr *io_uring_recvmsg_cmsg_nexthdr(struct io_uring_recvmsg_out *o,
+ struct msghdr *m,
+ struct cmsghdr *cmsg)
+{
+ unsigned char *end;
+
+ if (cmsg->cmsg_len < sizeof (struct cmsghdr))
+ return NULL;
+ end = (unsigned char *)io_uring_recvmsg_payload(o, m);
+ cmsg = (struct cmsghdr *)((unsigned char *)cmsg + CMSG_ALIGN(cmsg->cmsg_len));
+
+ if ((unsigned char *)(cmsg + 1) > end)
+ return NULL;
+ if (((unsigned char *)cmsg) + CMSG_ALIGN(cmsg->cmsg_len) > end)
+ return NULL;
+
+ return cmsg;
+}
+
static inline void io_uring_prep_openat2(struct io_uring_sqe *sqe, int dfd,
const char *path, struct open_how *how)
{
diff --git a/src/include/liburing/io_uring.h b/src/include/liburing/io_uring.h
index fbf6403..5e111b4 100644
--- a/src/include/liburing/io_uring.h
+++ b/src/include/liburing/io_uring.h
@@ -573,6 +573,13 @@ struct io_uring_file_index_range {
__u64 resv;
};
+struct io_uring_recvmsg_out {
+ __u32 namelen;
+ __u32 controllen;
+ __u32 payloadlen;
+ __u32 flags;
+};
+
/*
* accept flags stored in sqe->ioprio
*/
--
2.30.2
