How to increase net.core.rmem_max value from c code

Question

I tried to increase the value SO_RCVBUF by getsockopt(udp_fd, SOL_SOCKET, SO_RCVBUF, &rcvBufferSize, &sockOptSize) but I am not able to increase it more than rmem_

Answer 1

So please tell me how can I increase it by C Code

If the process has root rights, then let it printf the desired number to

/proc/sys/net/core/rmem_max