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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-16 00:22:29 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-16 00:22:29 +0300 |
commit | d635a69dd4981cc51f90293f5f64268620ed1565 (patch) | |
tree | 5e0a758b402ea7d624c25c3a343545dd29e80f31 /drivers/net/ppp/ppp_generic.c | |
parent | ac73e3dc8acd0a3be292755db30388c3580f5674 (diff) | |
parent | efd5a1584537698220578227e6467638307c2a0b (diff) | |
download | linux-d635a69dd4981cc51f90293f5f64268620ed1565.tar.xz |
Merge tag 'net-next-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Jakub Kicinski:
"Core:
- support "prefer busy polling" NAPI operation mode, where we defer
softirq for some time expecting applications to periodically busy
poll
- AF_XDP: improve efficiency by more batching and hindering the
adjacency cache prefetcher
- af_packet: make packet_fanout.arr size configurable up to 64K
- tcp: optimize TCP zero copy receive in presence of partial or
unaligned reads making zero copy a performance win for much smaller
messages
- XDP: add bulk APIs for returning / freeing frames
- sched: support fragmenting IP packets as they come out of conntrack
- net: allow virtual netdevs to forward UDP L4 and fraglist GSO skbs
BPF:
- BPF switch from crude rlimit-based to memcg-based memory accounting
- BPF type format information for kernel modules and related tracing
enhancements
- BPF implement task local storage for BPF LSM
- allow the FENTRY/FEXIT/RAW_TP tracing programs to use
bpf_sk_storage
Protocols:
- mptcp: improve multiple xmit streams support, memory accounting and
many smaller improvements
- TLS: support CHACHA20-POLY1305 cipher
- seg6: add support for SRv6 End.DT4/DT6 behavior
- sctp: Implement RFC 6951: UDP Encapsulation of SCTP
- ppp_generic: add ability to bridge channels directly
- bridge: Connectivity Fault Management (CFM) support as is defined
in IEEE 802.1Q section 12.14.
Drivers:
- mlx5: make use of the new auxiliary bus to organize the driver
internals
- mlx5: more accurate port TX timestamping support
- mlxsw:
- improve the efficiency of offloaded next hop updates by using
the new nexthop object API
- support blackhole nexthops
- support IEEE 802.1ad (Q-in-Q) bridging
- rtw88: major bluetooth co-existance improvements
- iwlwifi: support new 6 GHz frequency band
- ath11k: Fast Initial Link Setup (FILS)
- mt7915: dual band concurrent (DBDC) support
- net: ipa: add basic support for IPA v4.5
Refactor:
- a few pieces of in_interrupt() cleanup work from Sebastian Andrzej
Siewior
- phy: add support for shared interrupts; get rid of multiple driver
APIs and have the drivers write a full IRQ handler, slight growth
of driver code should be compensated by the simpler API which also
allows shared IRQs
- add common code for handling netdev per-cpu counters
- move TX packet re-allocation from Ethernet switch tag drivers to a
central place
- improve efficiency and rename nla_strlcpy
- number of W=1 warning cleanups as we now catch those in a patchwork
build bot
Old code removal:
- wan: delete the DLCI / SDLA drivers
- wimax: move to staging
- wifi: remove old WDS wifi bridging support"
* tag 'net-next-5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1922 commits)
net: hns3: fix expression that is currently always true
net: fix proc_fs init handling in af_packet and tls
nfc: pn533: convert comma to semicolon
af_vsock: Assign the vsock transport considering the vsock address flags
af_vsock: Set VMADDR_FLAG_TO_HOST flag on the receive path
vsock_addr: Check for supported flag values
vm_sockets: Add VMADDR_FLAG_TO_HOST vsock flag
vm_sockets: Add flags field in the vsock address data structure
net: Disable NETIF_F_HW_TLS_TX when HW_CSUM is disabled
tcp: Add logic to check for SYN w/ data in tcp_simple_retransmit
net: mscc: ocelot: install MAC addresses in .ndo_set_rx_mode from process context
nfc: s3fwrn5: Release the nfc firmware
net: vxget: clean up sparse warnings
mlxsw: spectrum_router: Use eXtended mezzanine to offload IPv4 router
mlxsw: spectrum: Set KVH XLT cache mode for Spectrum2/3
mlxsw: spectrum_router_xm: Introduce basic XM cache flushing
mlxsw: reg: Add Router LPM Cache Enable Register
mlxsw: reg: Add Router LPM Cache ML Delete Register
mlxsw: spectrum_router_xm: Implement L-value tracking for M-index
mlxsw: reg: Add XM Router M Table Register
...
Diffstat (limited to 'drivers/net/ppp/ppp_generic.c')
-rw-r--r-- | drivers/net/ppp/ppp_generic.c | 152 |
1 files changed, 149 insertions, 3 deletions
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c index 7d005896a0f9..09c27f7773f9 100644 --- a/drivers/net/ppp/ppp_generic.c +++ b/drivers/net/ppp/ppp_generic.c @@ -174,7 +174,8 @@ struct channel { struct ppp *ppp; /* ppp unit we're connected to */ struct net *chan_net; /* the net channel belongs to */ struct list_head clist; /* link in list of channels per unit */ - rwlock_t upl; /* protects `ppp' */ + rwlock_t upl; /* protects `ppp' and 'bridge' */ + struct channel __rcu *bridge; /* "bridged" ppp channel */ #ifdef CONFIG_PPP_MULTILINK u8 avail; /* flag used in multilink stuff */ u8 had_frag; /* >= 1 fragments have been sent */ @@ -606,6 +607,83 @@ static struct bpf_prog *compat_ppp_get_filter(struct sock_fprog32 __user *p) #endif #endif +/* Bridge one PPP channel to another. + * When two channels are bridged, ppp_input on one channel is redirected to + * the other's ops->start_xmit handler. + * In order to safely bridge channels we must reject channels which are already + * part of a bridge instance, or which form part of an existing unit. + * Once successfully bridged, each channel holds a reference on the other + * to prevent it being freed while the bridge is extant. + */ +static int ppp_bridge_channels(struct channel *pch, struct channel *pchb) +{ + write_lock_bh(&pch->upl); + if (pch->ppp || + rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl))) { + write_unlock_bh(&pch->upl); + return -EALREADY; + } + rcu_assign_pointer(pch->bridge, pchb); + write_unlock_bh(&pch->upl); + + write_lock_bh(&pchb->upl); + if (pchb->ppp || + rcu_dereference_protected(pchb->bridge, lockdep_is_held(&pchb->upl))) { + write_unlock_bh(&pchb->upl); + goto err_unset; + } + rcu_assign_pointer(pchb->bridge, pch); + write_unlock_bh(&pchb->upl); + + refcount_inc(&pch->file.refcnt); + refcount_inc(&pchb->file.refcnt); + + return 0; + +err_unset: + write_lock_bh(&pch->upl); + RCU_INIT_POINTER(pch->bridge, NULL); + write_unlock_bh(&pch->upl); + synchronize_rcu(); + return -EALREADY; +} + +static int ppp_unbridge_channels(struct channel *pch) +{ + struct channel *pchb, *pchbb; + + write_lock_bh(&pch->upl); + pchb = rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl)); + if (!pchb) { + write_unlock_bh(&pch->upl); + return -EINVAL; + } + RCU_INIT_POINTER(pch->bridge, NULL); + write_unlock_bh(&pch->upl); + + /* Only modify pchb if phcb->bridge points back to pch. + * If not, it implies that there has been a race unbridging (and possibly + * even rebridging) pchb. We should leave pchb alone to avoid either a + * refcount underflow, or breaking another established bridge instance. + */ + write_lock_bh(&pchb->upl); + pchbb = rcu_dereference_protected(pchb->bridge, lockdep_is_held(&pchb->upl)); + if (pchbb == pch) + RCU_INIT_POINTER(pchb->bridge, NULL); + write_unlock_bh(&pchb->upl); + + synchronize_rcu(); + + if (pchbb == pch) + if (refcount_dec_and_test(&pch->file.refcnt)) + ppp_destroy_channel(pch); + + if (refcount_dec_and_test(&pchb->file.refcnt)) + ppp_destroy_channel(pchb); + + return 0; +} + static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { struct ppp_file *pf; @@ -641,8 +719,9 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) } if (pf->kind == CHANNEL) { - struct channel *pch; + struct channel *pch, *pchb; struct ppp_channel *chan; + struct ppp_net *pn; pch = PF_TO_CHANNEL(pf); @@ -657,6 +736,31 @@ static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) err = ppp_disconnect_channel(pch); break; + case PPPIOCBRIDGECHAN: + if (get_user(unit, p)) + break; + err = -ENXIO; + pn = ppp_pernet(current->nsproxy->net_ns); + spin_lock_bh(&pn->all_channels_lock); + pchb = ppp_find_channel(pn, unit); + /* Hold a reference to prevent pchb being freed while + * we establish the bridge. + */ + if (pchb) + refcount_inc(&pchb->file.refcnt); + spin_unlock_bh(&pn->all_channels_lock); + if (!pchb) + break; + err = ppp_bridge_channels(pch, pchb); + /* Drop earlier refcount now bridge establishment is complete */ + if (refcount_dec_and_test(&pchb->file.refcnt)) + ppp_destroy_channel(pchb); + break; + + case PPPIOCUNBRIDGECHAN: + err = ppp_unbridge_channels(pch); + break; + default: down_read(&pch->chan_sem); chan = pch->chan; @@ -2089,6 +2193,40 @@ static bool ppp_decompress_proto(struct sk_buff *skb) return pskb_may_pull(skb, 2); } +/* Attempt to handle a frame via. a bridged channel, if one exists. + * If the channel is bridged, the frame is consumed by the bridge. + * If not, the caller must handle the frame by normal recv mechanisms. + * Returns true if the frame is consumed, false otherwise. + */ +static bool ppp_channel_bridge_input(struct channel *pch, struct sk_buff *skb) +{ + struct channel *pchb; + + rcu_read_lock(); + pchb = rcu_dereference(pch->bridge); + if (!pchb) + goto out_rcu; + + spin_lock(&pchb->downl); + if (!pchb->chan) { + /* channel got unregistered */ + kfree_skb(skb); + goto outl; + } + + skb_scrub_packet(skb, !net_eq(pch->chan_net, pchb->chan_net)); + if (!pchb->chan->ops->start_xmit(pchb->chan, skb)) + kfree_skb(skb); + +outl: + spin_unlock(&pchb->downl); +out_rcu: + rcu_read_unlock(); + + /* If pchb is set then we've consumed the packet */ + return !!pchb; +} + void ppp_input(struct ppp_channel *chan, struct sk_buff *skb) { @@ -2100,6 +2238,10 @@ ppp_input(struct ppp_channel *chan, struct sk_buff *skb) return; } + /* If the channel is bridged, transmit via. bridge */ + if (ppp_channel_bridge_input(pch, skb)) + return; + read_lock_bh(&pch->upl); if (!ppp_decompress_proto(skb)) { kfree_skb(skb); @@ -2796,8 +2938,11 @@ ppp_unregister_channel(struct ppp_channel *chan) list_del(&pch->list); spin_unlock_bh(&pn->all_channels_lock); + ppp_unbridge_channels(pch); + pch->file.dead = 1; wake_up_interruptible(&pch->file.rwait); + if (refcount_dec_and_test(&pch->file.refcnt)) ppp_destroy_channel(pch); } @@ -3270,7 +3415,8 @@ ppp_connect_channel(struct channel *pch, int unit) goto out; write_lock_bh(&pch->upl); ret = -EINVAL; - if (pch->ppp) + if (pch->ppp || + rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl))) goto outl; ppp_lock(ppp); |