libxdp: Assign default values for fields in xsk_umem_opts

Use 0 as default(or unset) value for fd when creating umem,
also, set fields to their default values if passed in by 0.

Signed-off-by: Muyang Tian <[email protected]>

Author: tacslon

lib/libxdp/xsk.c

@@ -316,7 +316,7 @@ struct xsk_umem *xsk_umem__create_opts(void *umem_area,
 		err = -EINVAL;
 		goto err;
 	}
-	fd = OPTS_GET(opts, fd, -1);
+	fd = OPTS_GET(opts, fd, 0);
 	size = OPTS_GET(opts, size, 0);
 
 	if (!size && !xsk_page_aligned(umem_area)) {
@@ -330,7 +330,7 @@ struct xsk_umem *xsk_umem__create_opts(void *umem_area,
 		goto err;
 	}
 
-	umem->fd = fd < 0 ? socket(AF_XDP, SOCK_RAW, 0) : fd;
+	umem->fd = fd > 0 ? fd : socket(AF_XDP, SOCK_RAW, 0);
 	if (umem->fd < 0) {
 		err = -errno;
 		goto out_umem_alloc;
@@ -379,26 +379,37 @@ int xsk_umem__create_with_fd(struct xsk_umem **umem_ptr, int fd,
 			     struct xsk_ring_cons *comp,
 			     const struct xsk_umem_config *usr_config)
 {
+	__u32 fill_size, comp_size, frame_size, frame_headroom, flags;
 	struct xsk_umem *umem;
 
 	if(!umem_ptr)
 		return -EFAULT;
 
+	if(!usr_config) {
+		fill_size = XSK_RING_PROD__DEFAULT_NUM_DESCS;
+		comp_size = XSK_RING_CONS__DEFAULT_NUM_DESCS;
+		frame_size = XSK_UMEM__DEFAULT_FRAME_SIZE;
+		frame_headroom = XSK_UMEM__DEFAULT_FRAME_HEADROOM;
+		flags = XSK_UMEM__DEFAULT_FLAGS;
+	} else {
+		/* Set the following fields to their default values if they are passed in as 0 */
+		fill_size = usr_config->fill_size ? usr_config->fill_size : XSK_RING_PROD__DEFAULT_NUM_DESCS;
+		comp_size = usr_config->comp_size ? usr_config->comp_size : XSK_RING_CONS__DEFAULT_NUM_DESCS;
+		frame_size = usr_config->frame_size ? usr_config->frame_size : XSK_UMEM__DEFAULT_FRAME_SIZE;
+		/* The following fields are 0 by default, just keep them as what they are passed in */
+		frame_headroom = usr_config->frame_headroom;
+		flags = usr_config->flags;
+	}
+
 	DECLARE_LIBXDP_OPTS(xsk_umem_opts, opts,
 		.fd = fd,
 		.size = size,
-		.fill_size = usr_config ? usr_config->fill_size
-			 : XSK_RING_PROD__DEFAULT_NUM_DESCS,
-		.comp_size = usr_config ? usr_config->comp_size
-			 : XSK_RING_CONS__DEFAULT_NUM_DESCS,
-		.frame_size = usr_config ? usr_config->frame_size
-			 : XSK_UMEM__DEFAULT_FRAME_SIZE,
-		.frame_headroom = usr_config ? usr_config->frame_headroom
-			 : XSK_UMEM__DEFAULT_FRAME_HEADROOM,
-		.flags = usr_config ? usr_config->flags
-			 : XSK_UMEM__DEFAULT_FLAGS,
+		.fill_size = fill_size,
+		.comp_size = comp_size,
+		.frame_size = frame_size,
+		.frame_headroom = frame_headroom,
+		.flags = flags,
 	);
-
 	umem = xsk_umem__create_opts(umem_area, fill, comp, &opts);
 	if(!umem)
 		return errno;
@@ -412,7 +423,7 @@ int xsk_umem__create(struct xsk_umem **umem_ptr, void *umem_area,
 		     struct xsk_ring_cons *comp,
 		     const struct xsk_umem_config *usr_config)
 {
-	return xsk_umem__create_with_fd(umem_ptr, -1, umem_area, size,
+	return xsk_umem__create_with_fd(umem_ptr, 0, umem_area, size,
 					fill, comp, usr_config);
 }