io_uring_recvmsg_validate - Man Page

#include <liburing.h>

struct io_uring_recvmsg_out *io_uring_recvmsg_validate(void *buf,
                                                       int buf_len,
                                                       struct msghdr *msgh);

void *io_uring_recvmsg_name(struct io_uring_recvmsg_out *o);

struct cmsghdr *io_uring_recvmsg_cmsg_firsthdr(struct io_uring_recvmsg_out *o,
                                               struct msghdr *msgh);
struct cmsghdr *io_uring_recvmsg_cmsg_nexthdr(struct io_uring_recvmsg_out *o,
                                              struct msghdr *msgh,
                                              struct cmsghdr *cmsg);

void *io_uring_recvmsg_payload(struct io_uring_recvmsg_out *o,
                               struct msghdr *msgh);
unsigned int io_uring_recvmsg_payload_length(struct io_uring_recvmsg_out *o,
                                             int buf_len,
                                             struct msghdr *msgh);

These functions are used to access data in the payload delivered by io_uring_prep_recvmsg_multishot(3).

msgh should point to the struct msghdr submitted with the request.

io_uring_recvmsg_validate(3) will validate a buffer delivered by io_uring_prep_recvmsg_multishot(3) and extract the io_uring_recvmsg_out if it is valid, returning a pointer to it or else NULL.

The structure is defined as follows:

struct io_uring_recvmsg_out {
        __u32 namelen;    /* Name byte count as would have been populated
                           * by recvmsg(2) */
        __u32 controllen; /* Control byte count */
        __u32 payloadlen; /* Payload byte count as would have been returned
                           * by recvmsg(2) */
        __u32 flags;      /* Flags result as would have been populated
                           * by recvmsg(2) */
};

*
io_uring_recvmsg_name(3)
    returns a pointer to the name in the buffer.
    *
io_uring_recvmsg_cmsg_firsthdr(3)
    returns a pointer to the first cmsg in the buffer, or NULL.
    *
io_uring_recvmsg_cmsg_nexthdr(3)
    returns a pointer to the next cmsg in the buffer, or NULL.
    *
io_uring_recvmsg_payload(3)
    returns a pointer to the payload in the buffer.
    *
io_uring_recvmsg_payload_length(3)
    Calculates the usable payload length in bytes.

io_uring_prep_recvmsg_multishot(3)

io_uring_prep_recvmsg(3).

The man pages io_uring_recvmsg_cmsg_firsthdr(3), io_uring_recvmsg_cmsg_nexthdr(3), io_uring_recvmsg_name(3), io_uring_recvmsg_out(3), io_uring_recvmsg_payload(3) and io_uring_recvmsg_payload_length(3) are aliases of io_uring_recvmsg_validate(3).