[PATCH 1/2] vector_user: add VDE support

[Anton Ivanov]

On 30/07/2024 14:54, Renzo Davoli wrote:
> This is the actual implementation of VDE support as a vector transport.
> 
> Signed-off-by: Renzo Davoli <renzo at cs.unibo.it>
> ---
>   arch/um/drivers/vector_user.c | 83 +++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 83 insertions(+)
> 
> diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
> index b16a5e5619d3..2ea67e6fd067 100644
> --- a/arch/um/drivers/vector_user.c
> +++ b/arch/um/drivers/vector_user.c
> @@ -46,6 +46,9 @@
>   #define TRANS_FD "fd"
>   #define TRANS_FD_LEN strlen(TRANS_FD)
>   
> +#define TRANS_VDE "vde"
> +#define TRANS_VDE_LEN strlen(TRANS_VDE)
> +
>   #define VNET_HDR_FAIL "could not enable vnet headers on fd %d"
>   #define TUN_GET_F_FAIL "tapraw: TUNGETFEATURES failed: %s"
>   #define L2TPV3_BIND_FAIL "l2tpv3_open : could not bind socket err=%i"
> @@ -434,6 +437,84 @@ static struct vector_fds *user_init_fd_fds(struct arglist *ifspec)
>   	return NULL;
>   }
>   
> +/* enough char to store an int type */
> +#define ENOUGH(type) ((CHAR_BIT * sizeof(type) - 1) / 3 + 2)
> +#define ENOUGH_OCTAL(type) ((CHAR_BIT * sizeof(type) + 2) / 3)
> +/* vde_plug --descr xx --port2 xx --mod2 xx --group2 xx seqpacket://NN vnl (NULL) */
> +#define VDE_MAX_ARGC 12
> +#define VDE_SEQPACKET_HEAD "seqpacket://"
> +#define VDE_SEQPACKET_HEAD_LEN (sizeof(VDE_SEQPACKET_HEAD) - 1)
> +#define VDE_DEFAULT_DESCRIPTION "UML"
> +
> +static struct vector_fds *user_init_vde_fds(struct arglist *ifspec)
> +{
> +	char seqpacketvnl[VDE_SEQPACKET_HEAD_LEN + ENOUGH(int) + 1];
> +	char *argv[VDE_MAX_ARGC] = {"vde_plug"};
> +	int argc = 1;
> +	int rv;
> +	int sv[2];
> +	struct vector_fds *result = NULL;
> +
> +	char *vnl = uml_vector_fetch_arg(ifspec,"vnl");
> +	char *descr = uml_vector_fetch_arg(ifspec,"descr");
> +	char *port = uml_vector_fetch_arg(ifspec,"port");
> +	char *mode = uml_vector_fetch_arg(ifspec,"mode");
> +	char *group = uml_vector_fetch_arg(ifspec,"group");
> +	if (descr == NULL) descr = VDE_DEFAULT_DESCRIPTION;
> +
> +	argv[argc++] = "--descr";
> +	argv[argc++] = descr;
> +	if (port != NULL) {
> +		argv[argc++] = "--port2";
> +		argv[argc++] = port;
> +	}
> +	if (mode != NULL) {
> +		argv[argc++] = "--mod2";
> +		argv[argc++] = mode;
> +	}
> +	if (group != NULL) {
> +		argv[argc++] = "--group2";
> +		argv[argc++] = group;
> +	}
> +	argv[argc++] = seqpacketvnl;
> +	argv[argc++] = vnl;
> +	argv[argc++] = NULL;
> +
> +	rv = socketpair(AF_UNIX, SOCK_SEQPACKET, 0, sv);
> +	if (rv  < 0) {
> +		printk(UM_KERN_ERR "vde: seqpacket socketpair err %d", -errno);
> +		return NULL;
> +	}
> +	rv = os_set_exec_close(sv[0]);
> +	if (rv  < 0) {
> +		printk(UM_KERN_ERR "vde: seqpacket socketpair cloexec err %d", -errno);
> +		goto vde_cleanup_sv;
> +	}
> +	snprintf(seqpacketvnl, sizeof(seqpacketvnl), VDE_SEQPACKET_HEAD "%d", sv[1]);
> +
> +	run_helper(NULL, NULL, argv);
> +
> +	close(sv[1]);
> +
> +	result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
> +	if (result == NULL) {
> +		printk(UM_KERN_ERR "fd open: allocation failed");
> +		goto vde_cleanup;
> +	}
> +
> +	result->rx_fd = sv[0];
> +	result->tx_fd = sv[0];
> +	result->remote_addr_size = 0;
> +	result->remote_addr = NULL;
> +	return result;
> +
> +vde_cleanup_sv:
> +	close(sv[1]);
> +vde_cleanup:
> +	close(sv[0]);
> +	return NULL;
> +}
> +
>   static struct vector_fds *user_init_raw_fds(struct arglist *ifspec)
>   {
>   	int rxfd = -1, txfd = -1;
> @@ -673,6 +754,8 @@ struct vector_fds *uml_vector_user_open(
>   		return user_init_unix_fds(parsed, ID_BESS);
>   	if (strncmp(transport, TRANS_FD, TRANS_FD_LEN) == 0)
>   		return user_init_fd_fds(parsed);
> +	if (strncmp(transport, TRANS_VDE, TRANS_VDE_LEN) == 0)
> +		return user_init_vde_fds(parsed);
>   	return NULL;
>   }
>   
> 
> 
> 
> 
Acked-By: Anton Ivanov <anton.ivanov at cambridgegreys.com>

-- 
Anton R. Ivanov
https://www.kot-begemot.co.uk/