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authorAnton Ivanov <anton.ivanov@cambridgegreys.com>2020-09-21 16:58:27 +0300
committerRichard Weinberger <richard@nod.at>2020-10-12 00:26:37 +0300
commitf06885b3f3e3884f98351d7b72a4fc8400911cde (patch)
tree786e92d66b1381f15982308221df79825b86e689 /arch/um
parent273fe1b676cb59d41e177980a981e27806872954 (diff)
downloadlinux-f06885b3f3e3884f98351d7b72a4fc8400911cde.tar.xz
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: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um')
-rw-r--r--arch/um/drivers/vector_user.c56
1 files changed, 47 insertions, 9 deletions
diff --git a/arch/um/drivers/vector_user.c b/arch/um/drivers/vector_user.c
index 65b6a71a132f..bae53220ce26 100644
--- a/arch/um/drivers/vector_user.c
+++ b/arch/um/drivers/vector_user.c
@@ -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) && (!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);
- fd = create_tap_fd(iface);
- if (fd < 0) {
- printk(UM_KERN_ERR "uml_tap: failed to create tun interface\n");
- goto tap_cleanup;
+ argv[0] = uml_vector_fetch_arg(ifspec, TOKEN_SCRIPT);
+ if (argv[0]) {
+ argv[1] = iface;
+ run_helper(NULL, NULL, argv);
}
- result->tx_fd = fd;
- result->rx_fd = fd;
+
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);