Interface names may be renamed by udev (systemd-udev) after creation
before the interface is up. Interfaces may also be renamed when
the interface is down due to a bluetoothd restart.
Use the interface index, that does not change on renaming, where possible.
Also do some retries when the creation of an interface fails.
---
profiles/network/bnep.c | 317 ++++++++++++++++++++++++++++++++++++++++--------
1 file changed, 265 insertions(+), 52 deletions(-)
diff --git a/profiles/network/bnep.c b/profiles/network/bnep.c
index 9bf0b18..b66f3c2 100644
--- a/profiles/network/bnep.c
+++ b/profiles/network/bnep.c
@@ -29,6 +29,7 @@
#include <errno.h>
#include <unistd.h>
#include <stdlib.h>
+#include <sched.h>
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
@@ -50,7 +51,7 @@
#include "bnep.h"
#define CON_SETUP_RETRIES 3
-#define CON_SETUP_TO 9
+#define CON_SETUP_TO 9
static int ctl;
@@ -65,6 +66,7 @@ struct bnep {
uint16_t dst;
bdaddr_t dst_addr;
char iface[16];
+ unsigned int ifindex;
guint attempts;
guint setup_to;
guint watch;
@@ -98,25 +100,110 @@ int bnep_cleanup(void)
return 0;
}
+/**
+ * private: for local use only.
+ *
+ * bnep_indextoname() - Return interface name corresponding to interface index.
+ * @ifindex interface index.
+ * @iface interface name, output only, will be filled with '<unknown>' in case of error.
+ *
+ * The name is placed in the buffer pointed to by ifname.
+ * The buffer must allow for the storage of at least IF_NAMESIZE bytes.
+ *
+ * On success 0 is returned. On error errno as a negative value is returned.
+ */
+static int bnep_indextoname(unsigned int ifindex, char *iface)
+{
+ int err;
+
+ err = 0;
+ if (if_indextoname(ifindex, iface) == 0) {
+ err = -errno;
+ strncpy(iface, "<unknown>", 10);
+ }
+ return err;
+}
+
+/**
+ * private: for local use only.
+ *
+ * bnep_nametoindext() - Return interface index corresponding to interface name.
+ * @iface interface name
+ * @ifindex interface index, output only, will be filled with 0 in case of error.
+ *
+ * The interface index is placed in the variable pointed to by ifindex.
+ *
+ * In case the interface is temporarily unavailable do a retry.
+ *
+ * On success 0 is returned. On error errno as a negative value is returned.
+ */
+static int bnep_nametoindex(const char *iface, unsigned int *ifindex)
+{
+ int retry;
+ int err;
+
+ retry = 0;
+ while (retry < 2) {
+ *ifindex = if_nametoindex(iface);
+ if (*ifindex != 0) {
+ err = 0;
+ DBG("got interface index %d for interface %s retry %d",
+ *ifindex, iface, retry);
+ } else {
+ err = -errno;
+ DBG("failed to get interface index for interface %s retry %d: %s (%d)",
+ iface, retry, strerror(-err), -err);
+ }
+ if (err != -EAGAIN)
+ break;
+ /* EAGAIN - Resource temporarily unavailable */
+ retry++;
+ sched_yield();
+ }
+ return err;
+}
+
static int bnep_conndel(const bdaddr_t *dst)
{
+ int err;
struct bnep_conndel_req req;
+ char addr[20];
+ ba2str(dst, &addr[0]);
memset(&req, 0, sizeof(req));
baswap((bdaddr_t *)&req.dst, dst);
req.flags = 0;
- if (ioctl(ctl, BNEPCONNDEL, &req) < 0) {
- int err = -errno;
- error("bnep: Failed to kill connection: %s (%d)",
- strerror(-err), -err);
+ err = ioctl(ctl, BNEPCONNDEL, &req);
+ if (err < 0) {
+ err = -errno;
+ error("bnep: Failed to kill connection %s: %s (%d)",
+ addr, strerror(-err), -err);
return err;
}
+ DBG("deleted device %s, %d", addr, err);
+
return 0;
}
-static int bnep_connadd(int sk, uint16_t role, char *dev)
+/**
+ * private: for local use only.
+ *
+ * bnep_connadd() - Add bluetooth ethernet connection.
+ * @sk bluez control socket.
+ * @role
+ * @dev device name, template for new interface name (e.g. "bnep%d") or name.
+ * @dst bluetooth address, only needed for retries.
+ * @ifindex interface index, ouput only - new interface index
+ *
+ * In case the interface can not be accessed by the device name (e.g. due to udev rename) do a retry.
+ *
+ * On success 0 is returned. On error errno as a negative value is returned.
+ */
+static int bnep_connadd(int sk, uint16_t role, char *dev, const bdaddr_t *dst, unsigned int *ifindex)
{
struct bnep_connadd_req req;
+ int err;
+ int retry;
memset(&req, 0, sizeof(req));
strncpy(req.device, dev, 16);
@@ -125,15 +212,42 @@ static int bnep_connadd(int sk, uint16_t role, char *dev)
req.sock = sk;
req.role = role;
req.flags = (1 << BNEP_SETUP_RESPONSE);
- if (ioctl(ctl, BNEPCONNADD, &req) < 0) {
- int err = -errno;
- error("bnep: Failed to add device %s: %s(%d)",
- dev, strerror(-err), -err);
- return err;
+
+ retry = 0;
+
+ while (retry < 2) {
+ err = ioctl(ctl, BNEPCONNADD, &req);
+ if (err < 0) {
+ err = -errno;
+ DBG("failed to add device %s retry %d: %s(%d)",
+ req.device, retry, strerror(-err), -err);
+ break;
+ }
+ /*
+ * There is a potential race condition between udev renaming the interface
+ * after being created by BNEPCONNADD and bnep_nametoindex providing
+ * the interface index.
+ */
+ err = bnep_nametoindex(&req.device[0], ifindex);
+ if (!err) {
+ DBG("added device %s with interface index %d retry %d ",
+ req.device, retry, *ifindex);
+ break;
+ }
+
+ /* Prepare retry */
+ bnep_conndel(dst);
+ retry++;
+ DBG("failed to add device %s retry %d", req.device, retry);
+ sched_yield();
+ }
+
+ if (err) {
+ error("bnep: Failed to add device %s with interface index %d: %s(%d)",
+ req.device, *ifindex, strerror(-err), -err);
}
- strncpy(dev, req.device, 16);
- return 0;
+ return err;
}
static uint32_t bnep_getsuppfeat(void)
@@ -148,51 +262,108 @@ static uint32_t bnep_getsuppfeat(void)
return feat;
}
-static int bnep_if_up(const char *devname)
+/**
+ * private: for local use only.
+ *
+ * bnep_if_up() - Bring interface up.
+ * @ifindex interface index
+ *
+ * In case the interface can not be accessed (e.g. due to udev rename) do a retry.
+ *
+ * On success 0 is returned. On error errno as a negative value is returned.
+ */
+static int bnep_if_up(unsigned int ifindex)
{
struct ifreq ifr;
- int sk, err = 0;
+ int sk, err;
+ int retry;
sk = socket(AF_INET, SOCK_DGRAM, 0);
memset(&ifr, 0, sizeof(ifr));
- strncpy(ifr.ifr_name, devname, IF_NAMESIZE - 1);
-
ifr.ifr_flags |= IFF_UP;
ifr.ifr_flags |= IFF_MULTICAST;
- if (ioctl(sk, SIOCSIFFLAGS, (void *) &ifr) < 0) {
+ retry = 0;
+ while (retry < 2) {
+ err = bnep_indextoname(ifindex, ifr.ifr_name);
+ if (err)
+ break;
+ /*
+ * There is a potential race condition between udev renaming the interface
+ * after the name is retrieved by bnep_nametoindex and the usage of the
+ * interface name by ioctl.
+ */
+ if (ioctl(sk, SIOCSIFFLAGS, (void *) &ifr) == 0)
+ break;
err = -errno;
- error("bnep: Could not bring up %s: %s(%d)",
- devname, strerror(-err), -err);
+ DBG("could not bring up interface %s with index %d: %s(%d) retry %d",
+ ifr.ifr_name, ifindex, strerror(-err), -err, retry);
+
+ /* Prepare retry */
+ retry++;
+ sched_yield();
}
close(sk);
+ if (err) {
+ error("bnep: Could not bring up interface %s with index %d: %s(%d)",
+ ifr.ifr_name, ifindex, strerror(-err), -err);
+ }
+
return err;
}
-static int bnep_if_down(const char *devname)
+/**
+ * private: for local use only.
+ *
+ * bnep_if_down() - Bring interface down.
+ * @ifindex interface index
+ *
+ * In case the interface can not be accessed (e.g. due to udev rename) do a retry.
+ *
+ * On success 0 is returned. On error errno as a negative value is returned.
+ */
+static int bnep_if_down(unsigned int ifindex)
{
struct ifreq ifr;
- int sk, err = 0;
+ int sk, err;
+ int retry;
sk = socket(AF_INET, SOCK_DGRAM, 0);
memset(&ifr, 0, sizeof(ifr));
- strncpy(ifr.ifr_name, devname, IF_NAMESIZE - 1);
-
ifr.ifr_flags &= ~IFF_UP;
- /* Bring down the interface */
- if (ioctl(sk, SIOCSIFFLAGS, (void *) &ifr) < 0) {
+ retry = 0;
+ while (retry < 2) {
+ err = bnep_indextoname(ifindex, ifr.ifr_name);
+ if (err)
+ break;
+ /*
+ * There is a potential race condition between udev renaming the interface
+ * after the name is retrieved by bnep_nametoindex and the usage of the
+ * interface name by ioctl.
+ */
+ if (ioctl(sk, SIOCSIFFLAGS, (void *) &ifr) == 0)
+ break;
err = -errno;
- error("bnep: Could not bring down %s: %s(%d)",
- devname, strerror(-err), -err);
+ DBG("could not bring down interface %s with index %d: %s(%d) retry %d",
+ ifr.ifr_name, ifindex, strerror(-err), -err, retry);
+
+ /* Prepare retry */
+ retry++;
+ sched_yield();
}
close(sk);
+ if (err) {
+ error("bnep: Could not bring down interface %s with index %d: %s(%d)",
+ ifr.ifr_name, ifindex, strerror(-err), -err);
+ }
+
return err;
}
@@ -270,14 +441,19 @@ static gboolean bnep_setup_cb(GIOChannel *chan, GIOCondition cond,
setsockopt(sk, SOL_SOCKET, SO_RCVTIMEO, &timeo, sizeof(timeo));
sk = g_io_channel_unix_get_fd(session->io);
- if (bnep_connadd(sk, session->src, session->iface) < 0)
+ if (bnep_connadd(sk, session->src, session->iface, &session->dst_addr, &session->ifindex) < 0)
goto failed;
- if (bnep_if_up(session->iface) < 0) {
+ if (bnep_if_up(session->ifindex) < 0) {
bnep_conndel(&session->dst_addr);
goto failed;
}
+ /* Update interface name to current one only after interface is up.
+ * Only at that time the name should be stable (no udev rename).
+ */
+ bnep_indextoname(session->ifindex, session->iface);
+
session->watch = g_io_add_watch(session->io,
G_IO_ERR | G_IO_HUP | G_IO_NVAL,
(GIOFunc) bnep_watchdog_cb, session);
@@ -305,7 +481,7 @@ static int bnep_setup_conn_req(struct bnep *session)
req = (void *) pkt;
req->type = BNEP_CONTROL;
req->ctrl = BNEP_SETUP_CONN_REQ;
- req->uuid_size = 2; /* 16bit UUID */
+ req->uuid_size = 2; /* 16bit UUID */
s = (void *) req->service;
s->src = htons(session->src);
s->dst = htons(session->dst);
@@ -354,6 +530,7 @@ struct bnep *bnep_new(int sk, uint16_t local_role, uint16_t remote_role,
session->dst = remote_role;
strncpy(session->iface, iface, 16);
session->iface[15] = '\0';
+ session->ifindex = 0;
g_io_channel_set_close_on_unref(session->io, TRUE);
session->watch = g_io_add_watch(session->io,
@@ -430,20 +607,26 @@ void bnep_disconnect(struct bnep *session)
session->io = NULL;
}
- bnep_if_down(session->iface);
+ bnep_if_down(session->ifindex);
bnep_conndel(&session->dst_addr);
}
-static int bnep_add_to_bridge(const char *devname, const char *bridge)
+static int bnep_add_to_bridge(unsigned int ifindex, const char *bridge)
{
- int ifindex;
struct ifreq ifr;
int sk, err = 0;
+ char devname[IF_NAMESIZE];
- if (!devname || !bridge)
+ DBG("add interface index %d to bridge %s", ifindex, bridge);
+ if (!ifindex || !bridge)
return -EINVAL;
- ifindex = if_nametoindex(devname);
+ err = bnep_indextoname(ifindex, &devname[0]);
+ if (err) {
+ error("bnep: Can't add interface %s with index %d to the bridge %s: %s(%d)",
+ devname, ifindex, bridge, strerror(-err), -err);
+ return -EINVAL;
+ }
sk = socket(AF_INET, SOCK_STREAM, 0);
if (sk < 0)
@@ -451,7 +634,8 @@ static int bnep_add_to_bridge(const char *devname, const char *bridge)
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, bridge, IFNAMSIZ - 1);
- ifr.ifr_ifindex = ifindex;
+ ifr.ifr_ifindex = (int)ifindex;
+
if (ioctl(sk, SIOCBRADDIF, &ifr) < 0) {
err = -errno;
@@ -466,16 +650,21 @@ static int bnep_add_to_bridge(const char *devname, const char *bridge)
return err;
}
-static int bnep_del_from_bridge(const char *devname, const char *bridge)
+static int bnep_del_from_bridge(unsigned int ifindex, const char *bridge)
{
- int ifindex;
struct ifreq ifr;
int sk, err = 0;
+ char devname[IF_NAMESIZE];
- if (!devname || !bridge)
+ if (!ifindex || !bridge)
return -EINVAL;
- ifindex = if_nametoindex(devname);
+ err = bnep_indextoname(ifindex, &devname[0]);
+ if (err) {
+ error("bnep: Can't delete interface %s with index %d from the bridge %s: %s(%d)",
+ devname, ifindex, bridge, strerror(-err), -err);
+ return -EINVAL;
+ }
sk = socket(AF_INET, SOCK_STREAM, 0);
if (sk < 0)
@@ -483,7 +672,7 @@ static int bnep_del_from_bridge(const char *devname, const char *bridge)
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, bridge, IFNAMSIZ - 1);
- ifr.ifr_ifindex = ifindex;
+ ifr.ifr_ifindex = (int)ifindex;
if (ioctl(sk, SIOCBRDELIF, &ifr) < 0) {
err = -errno;
@@ -606,6 +795,7 @@ static int bnep_server_add_legacy(int sk, uint16_t dst, char *bridge,
char *iface, const bdaddr_t *addr,
uint8_t *setup_data, int len)
{
+ unsigned int ifindex;
int err, n;
uint16_t rsp;
@@ -616,27 +806,32 @@ static int bnep_server_add_legacy(int sk, uint16_t dst, char *bridge,
goto reply;
}
- err = bnep_connadd(sk, dst, iface);
+ err = bnep_connadd(sk, dst, iface, addr, &ifindex);
if (err < 0) {
rsp = BNEP_CONN_NOT_ALLOWED;
goto reply;
}
- err = bnep_add_to_bridge(iface, bridge);
+ err = bnep_add_to_bridge(ifindex, bridge);
if (err < 0) {
bnep_conndel(addr);
rsp = BNEP_CONN_NOT_ALLOWED;
goto reply;
}
- err = bnep_if_up(iface);
+ err = bnep_if_up(ifindex);
if (err < 0) {
- bnep_del_from_bridge(iface, bridge);
+ bnep_del_from_bridge(ifindex, bridge);
bnep_conndel(addr);
rsp = BNEP_CONN_NOT_ALLOWED;
goto reply;
}
+ /* Update interface name to current one only after interface is up.
+ * Only at that time the name should be stable (no udev rename).
+ */
+ bnep_indextoname(ifindex, iface);
+
rsp = BNEP_SUCCESS;
reply:
@@ -652,6 +847,7 @@ reply:
int bnep_server_add(int sk, char *bridge, char *iface, const bdaddr_t *addr,
uint8_t *setup_data, int len)
{
+ unsigned int ifindex;
int err;
uint32_t feat;
uint16_t rsp, dst;
@@ -691,24 +887,29 @@ int bnep_server_add(int sk, char *bridge, char *iface, const bdaddr_t *addr,
return bnep_server_add_legacy(sk, dst, bridge, iface, addr,
setup_data, len);
- err = bnep_connadd(sk, dst, iface);
+ err = bnep_connadd(sk, dst, iface, addr, &ifindex);
if (err < 0) {
rsp = BNEP_CONN_NOT_ALLOWED;
goto failed;
}
- err = bnep_add_to_bridge(iface, bridge);
+ err = bnep_add_to_bridge(ifindex, bridge);
if (err < 0)
goto failed_conn;
- err = bnep_if_up(iface);
+ err = bnep_if_up(ifindex);
if (err < 0)
goto failed_bridge;
+ /* Update interface name to current one only after interface is up.
+ * Only at that time the name should be stable (no udev rename).
+ */
+ bnep_indextoname(ifindex, iface);
+
return 0;
failed_bridge:
- bnep_del_from_bridge(iface, bridge);
+ bnep_del_from_bridge(ifindex, bridge);
failed_conn:
bnep_conndel(addr);
@@ -727,10 +928,22 @@ failed:
void bnep_server_delete(char *bridge, char *iface, const bdaddr_t *addr)
{
+ int err;
+ unsigned int ifindex;
+
if (!bridge || !iface || !addr)
return;
- bnep_del_from_bridge(iface, bridge);
- bnep_if_down(iface);
+ err = bnep_nametoindex(iface, &ifindex);
+ if (err) {
+ error("bnep: Failed to delete device %s - interface not available/ renamed: %s(%d)",
+ iface, strerror(-err), -err);
+ goto failed;
+ }
+
+ bnep_del_from_bridge(ifindex, bridge);
+ bnep_if_down(ifindex);
+failed:
bnep_conndel(addr);
}
+
--
2.7.4
--
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