Re: [PATCH v4 04/25] ibtrs: core: lib functions shared between client and server modules

[Bart Van Assche <bvanassche@acm.org>]

On 6/20/19 8:03 AM, Jack Wang wrote:
> +static int ibtrs_str_gid_to_sockaddr(const char *addr, size_t len,
> +				     short port, struct sockaddr_storage *dst)
> +{
> +	struct sockaddr_ib *dst_ib = (struct sockaddr_ib *)dst;
> +	int ret;
> +
> +	/*
> +	 * We can use some of the I6 functions since GID is a valid
> +	 * IPv6 address format
> +	 */
> +	ret = in6_pton(addr, len, dst_ib->sib_addr.sib_raw, '\0', NULL);
> +	if (ret == 0)
> +		return -EINVAL;
> +
> +	dst_ib->sib_family = AF_IB;
> +	/*
> +	 * Use the same TCP server port number as the IB service ID
> +	 * on the IB port space range
> +	 */
> +	dst_ib->sib_sid = cpu_to_be64(RDMA_IB_IP_PS_IB | port);
> +	dst_ib->sib_sid_mask = cpu_to_be64(0xffffffffffffffffULL);
> +	dst_ib->sib_pkey = cpu_to_be16(0xffff);
> +
> +	return 0;
> +}
> +
> +/**
> + * ibtrs_str_to_sockaddr() - Convert ibtrs address string to sockaddr
> + * @addr	String representation of an addr (IPv4, IPv6 or IB GID):
> + *              - "ip:192.168.1.1"
> + *              - "ip:fe80::200:5aee:feaa:20a2"
> + *              - "gid:fe80::200:5aee:feaa:20a2"
> + * @len         String address length
> + * @port	Destination port
> + * @dst		Destination sockaddr structure
> + *
> + * Returns 0 if conversion successful. Non-zero on error.
> + */
> +static int ibtrs_str_to_sockaddr(const char *addr, size_t len,
> +				 short port, struct sockaddr_storage *dst)
> +{
> +	if (strncmp(addr, "gid:", 4) == 0) {
> +		return ibtrs_str_gid_to_sockaddr(addr + 4, len - 4, port, dst);
> +	} else if (strncmp(addr, "ip:", 3) == 0) {
> +		char port_str[8];
> +		char *cpy;
> +		int err;
> +
> +		snprintf(port_str, sizeof(port_str), "%u", port);
> +		cpy = kstrndup(addr + 3, len - 3, GFP_KERNEL);
> +		err = cpy ? inet_pton_with_scope(&init_net, AF_UNSPEC,
> +						 cpy, port_str, dst) : -ENOMEM;
> +		kfree(cpy);
> +
> +		return err;
> +	}
> +	return -EPROTONOSUPPORT;
> +}

A considerable amount of code is required to support the IB/CM. Does 
supporting the IB/CM add any value? If that code would be left out, 
would anything break? Is it really useful to support IB networks where 
no IP address has been assigned to each IB port?

Thanks,

Bart.