Commit f06885b3 authored by Anton Ivanov's avatar Anton Ivanov Committed by Richard Weinberger
Browse files

um: vector: Add dynamic tap interfaces and scripting 



Provide functionality roughly compatible with the existing qemu
ifup scripting:
* invocation of an ifup script. The interface name is passed as the
  first and only argument
* allocating tap interfaces on the fly if they are not explicitly
  specified

Signed-off-by: default avatarAnton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
parent 273fe1b6

arch/um/drivers/vector_user.c

+47 −9
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ 
#define ID_MAX 2



#define TOKEN_IFNAME "ifname"

#define TOKEN_SCRIPT "ifup"



#define TRANS_RAW "raw"

#define TRANS_RAW_LEN strlen(TRANS_RAW)
@@ -53,6 +54,9 @@ 


#define MAX_UN_LEN 107



static const char padchar[] = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";

static const char *template = "tapXXXXXX";



/* This is very ugly and brute force lookup, but it is done

 * only once at initialization so not worth doing hashes or

 * anything more intelligent
@@ -189,16 +193,21 @@ raw_fd_cleanup: 
	return err;

}





static struct vector_fds *user_init_tap_fds(struct arglist *ifspec)

{

	int fd = -1;

	int fd = -1, i;

	char *iface;

	struct vector_fds *result = NULL;

	bool dynamic = false;

	char dynamic_ifname[IFNAMSIZ];

	char *argv[] = {NULL, NULL, NULL, NULL};



	iface = uml_vector_fetch_arg(ifspec, TOKEN_IFNAME);

	if (iface == NULL) {

		printk(UM_KERN_ERR "uml_tap: failed to parse interface spec\n");

		goto tap_cleanup;

		dynamic = true;

		iface = dynamic_ifname;

		srand(getpid());

	}



	result = uml_kmalloc(sizeof(struct vector_fds), UM_GFP_KERNEL);
@@ -212,14 +221,30 @@ static struct vector_fds *user_init_tap_fds(struct arglist *ifspec) 
	result->remote_addr_size = 0;



	/* TAP */



	do {

		if (dynamic) {

			strcpy(iface, template);

			for (i = 0; i < strlen(iface); i++) {

				if (iface[i] == 'X') {

					iface[i] = padchar[rand() % strlen(padchar)];

				}

			}

		}

		fd = create_tap_fd(iface);

	if (fd < 0) {

		if ((fd < 0) && (!dynamic)) {

			printk(UM_KERN_ERR "uml_tap: failed to create tun interface\n");

			goto tap_cleanup;

		}

		result->tx_fd = fd;

		result->rx_fd = fd;

	} while (fd < 0);



	argv[0] = uml_vector_fetch_arg(ifspec, TOKEN_SCRIPT);

	if (argv[0]) {

		argv[1] = iface;

		run_helper(NULL, NULL, argv);

	}



	return result;

tap_cleanup:

	printk(UM_KERN_ERR "user_init_tap: init failed, error %d", fd);
@@ -231,6 +256,7 @@ static struct vector_fds *user_init_hybrid_fds(struct arglist *ifspec) 
{

	char *iface;

	struct vector_fds *result = NULL;

	char *argv[] = {NULL, NULL, NULL, NULL};



	iface = uml_vector_fetch_arg(ifspec, TOKEN_IFNAME);

	if (iface == NULL) {
@@ -264,6 +290,12 @@ static struct vector_fds *user_init_hybrid_fds(struct arglist *ifspec) 
			"uml_tap: failed to create paired raw socket: %i\n", result->rx_fd);

		goto hybrid_cleanup;

	}



	argv[0] = uml_vector_fetch_arg(ifspec, TOKEN_SCRIPT);

	if (argv[0]) {

		argv[1] = iface;

		run_helper(NULL, NULL, argv);

	}

	return result;

hybrid_cleanup:

	printk(UM_KERN_ERR "user_init_hybrid: init failed");
@@ -407,6 +439,7 @@ static struct vector_fds *user_init_raw_fds(struct arglist *ifspec) 
	int err = -ENOMEM;

	char *iface;

	struct vector_fds *result = NULL;

	char *argv[] = {NULL, NULL, NULL, NULL};



	iface = uml_vector_fetch_arg(ifspec, TOKEN_IFNAME);

	if (iface == NULL)
@@ -429,6 +462,11 @@ static struct vector_fds *user_init_raw_fds(struct arglist *ifspec) 
		result->remote_addr = NULL;

		result->remote_addr_size = 0;

	}

	argv[0] = uml_vector_fetch_arg(ifspec, TOKEN_SCRIPT);

	if (argv[0]) {

		argv[1] = iface;

		run_helper(NULL, NULL, argv);

	}

	return result;

raw_cleanup:

	printk(UM_KERN_ERR "user_init_raw: init failed, error %d", err);

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