-
Notifications
You must be signed in to change notification settings - Fork 0
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
yaml --- r: 59055 b: refs/heads/master c: 50b65cc h: refs/heads/master i: 59053: 68b1f82 59051: c7cb853 59047: cdac015 59039: 88f643a v: v3
- Loading branch information
David S. Miller
committed
Jul 12, 2007
1 parent
f4773aa
commit 61d6e82
Showing
1,308 changed files
with
49,663 additions
and
102,674 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -1,2 +1,2 @@ | ||
| --- | ||
| refs/heads/master: 5b7f990927fe87ad3bec762a33c0e72bcbf6841e | ||
| refs/heads/master: 50b65cc6fa3a69bdfbc8b3342d8ca6ddbbf5ec88 |
16 changes: 16 additions & 0 deletions
16
trunk/Documentation/ABI/removed/raw1394_legacy_isochronous
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,16 @@ | ||
| What: legacy isochronous ABI of raw1394 (1st generation iso ABI) | ||
| Date: June 2007 (scheduled), removed in kernel v2.6.23 | ||
| Contact: linux1394-devel@lists.sourceforge.net | ||
| Description: | ||
| The two request types RAW1394_REQ_ISO_SEND, RAW1394_REQ_ISO_LISTEN have | ||
| been deprecated for quite some time. They are very inefficient as they | ||
| come with high interrupt load and several layers of callbacks for each | ||
| packet. Because of these deficiencies, the video1394 and dv1394 drivers | ||
| and the 3rd-generation isochronous ABI in raw1394 (rawiso) were created. | ||
|
|
||
| Users: | ||
| libraw1394 users via the long deprecated API raw1394_iso_write, | ||
| raw1394_start_iso_write, raw1394_start_iso_rcv, raw1394_stop_iso_rcv | ||
|
|
||
| libdc1394, which optionally uses these old libraw1394 calls | ||
| alternatively to the more efficient video1394 ABI |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,169 @@ | ||
| This brief document describes how to use the kernel's PPPoL2TP driver | ||
| to provide L2TP functionality. L2TP is a protocol that tunnels one or | ||
| more PPP sessions over a UDP tunnel. It is commonly used for VPNs | ||
| (L2TP/IPSec) and by ISPs to tunnel subscriber PPP sessions over an IP | ||
| network infrastructure. | ||
|
|
||
| Design | ||
| ====== | ||
|
|
||
| The PPPoL2TP driver, drivers/net/pppol2tp.c, provides a mechanism by | ||
| which PPP frames carried through an L2TP session are passed through | ||
| the kernel's PPP subsystem. The standard PPP daemon, pppd, handles all | ||
| PPP interaction with the peer. PPP network interfaces are created for | ||
| each local PPP endpoint. | ||
|
|
||
| The L2TP protocol http://www.faqs.org/rfcs/rfc2661.html defines L2TP | ||
| control and data frames. L2TP control frames carry messages between | ||
| L2TP clients/servers and are used to setup / teardown tunnels and | ||
| sessions. An L2TP client or server is implemented in userspace and | ||
| will use a regular UDP socket per tunnel. L2TP data frames carry PPP | ||
| frames, which may be PPP control or PPP data. The kernel's PPP | ||
| subsystem arranges for PPP control frames to be delivered to pppd, | ||
| while data frames are forwarded as usual. | ||
|
|
||
| Each tunnel and session within a tunnel is assigned a unique tunnel_id | ||
| and session_id. These ids are carried in the L2TP header of every | ||
| control and data packet. The pppol2tp driver uses them to lookup | ||
| internal tunnel and/or session contexts. Zero tunnel / session ids are | ||
| treated specially - zero ids are never assigned to tunnels or sessions | ||
| in the network. In the driver, the tunnel context keeps a pointer to | ||
| the tunnel UDP socket. The session context keeps a pointer to the | ||
| PPPoL2TP socket, as well as other data that lets the driver interface | ||
| to the kernel PPP subsystem. | ||
|
|
||
| Note that the pppol2tp kernel driver handles only L2TP data frames; | ||
| L2TP control frames are simply passed up to userspace in the UDP | ||
| tunnel socket. The kernel handles all datapath aspects of the | ||
| protocol, including data packet resequencing (if enabled). | ||
|
|
||
| There are a number of requirements on the userspace L2TP daemon in | ||
| order to use the pppol2tp driver. | ||
|
|
||
| 1. Use a UDP socket per tunnel. | ||
|
|
||
| 2. Create a single PPPoL2TP socket per tunnel bound to a special null | ||
| session id. This is used only for communicating with the driver but | ||
| must remain open while the tunnel is active. Opening this tunnel | ||
| management socket causes the driver to mark the tunnel socket as an | ||
| L2TP UDP encapsulation socket and flags it for use by the | ||
| referenced tunnel id. This hooks up the UDP receive path via | ||
| udp_encap_rcv() in net/ipv4/udp.c. PPP data frames are never passed | ||
| in this special PPPoX socket. | ||
|
|
||
| 3. Create a PPPoL2TP socket per L2TP session. This is typically done | ||
| by starting pppd with the pppol2tp plugin and appropriate | ||
| arguments. A PPPoL2TP tunnel management socket (Step 2) must be | ||
| created before the first PPPoL2TP session socket is created. | ||
|
|
||
| When creating PPPoL2TP sockets, the application provides information | ||
| to the driver about the socket in a socket connect() call. Source and | ||
| destination tunnel and session ids are provided, as well as the file | ||
| descriptor of a UDP socket. See struct pppol2tp_addr in | ||
| include/linux/if_ppp.h. Note that zero tunnel / session ids are | ||
| treated specially. When creating the per-tunnel PPPoL2TP management | ||
| socket in Step 2 above, zero source and destination session ids are | ||
| specified, which tells the driver to prepare the supplied UDP file | ||
| descriptor for use as an L2TP tunnel socket. | ||
|
|
||
| Userspace may control behavior of the tunnel or session using | ||
| setsockopt and ioctl on the PPPoX socket. The following socket | ||
| options are supported:- | ||
|
|
||
| DEBUG - bitmask of debug message categories. See below. | ||
| SENDSEQ - 0 => don't send packets with sequence numbers | ||
| 1 => send packets with sequence numbers | ||
| RECVSEQ - 0 => receive packet sequence numbers are optional | ||
| 1 => drop receive packets without sequence numbers | ||
| LNSMODE - 0 => act as LAC. | ||
| 1 => act as LNS. | ||
| REORDERTO - reorder timeout (in millisecs). If 0, don't try to reorder. | ||
|
|
||
| Only the DEBUG option is supported by the special tunnel management | ||
| PPPoX socket. | ||
|
|
||
| In addition to the standard PPP ioctls, a PPPIOCGL2TPSTATS is provided | ||
| to retrieve tunnel and session statistics from the kernel using the | ||
| PPPoX socket of the appropriate tunnel or session. | ||
|
|
||
| Debugging | ||
| ========= | ||
|
|
||
| The driver supports a flexible debug scheme where kernel trace | ||
| messages may be optionally enabled per tunnel and per session. Care is | ||
| needed when debugging a live system since the messages are not | ||
| rate-limited and a busy system could be swamped. Userspace uses | ||
| setsockopt on the PPPoX socket to set a debug mask. | ||
|
|
||
| The following debug mask bits are available: | ||
|
|
||
| PPPOL2TP_MSG_DEBUG verbose debug (if compiled in) | ||
| PPPOL2TP_MSG_CONTROL userspace - kernel interface | ||
| PPPOL2TP_MSG_SEQ sequence numbers handling | ||
| PPPOL2TP_MSG_DATA data packets | ||
|
|
||
| Sample Userspace Code | ||
| ===================== | ||
|
|
||
| 1. Create tunnel management PPPoX socket | ||
|
|
||
| kernel_fd = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP); | ||
| if (kernel_fd >= 0) { | ||
| struct sockaddr_pppol2tp sax; | ||
| struct sockaddr_in const *peer_addr; | ||
|
|
||
| peer_addr = l2tp_tunnel_get_peer_addr(tunnel); | ||
| memset(&sax, 0, sizeof(sax)); | ||
| sax.sa_family = AF_PPPOX; | ||
| sax.sa_protocol = PX_PROTO_OL2TP; | ||
| sax.pppol2tp.fd = udp_fd; /* fd of tunnel UDP socket */ | ||
| sax.pppol2tp.addr.sin_addr.s_addr = peer_addr->sin_addr.s_addr; | ||
| sax.pppol2tp.addr.sin_port = peer_addr->sin_port; | ||
| sax.pppol2tp.addr.sin_family = AF_INET; | ||
| sax.pppol2tp.s_tunnel = tunnel_id; | ||
| sax.pppol2tp.s_session = 0; /* special case: mgmt socket */ | ||
| sax.pppol2tp.d_tunnel = 0; | ||
| sax.pppol2tp.d_session = 0; /* special case: mgmt socket */ | ||
|
|
||
| if(connect(kernel_fd, (struct sockaddr *)&sax, sizeof(sax) ) < 0 ) { | ||
| perror("connect failed"); | ||
| result = -errno; | ||
| goto err; | ||
| } | ||
| } | ||
|
|
||
| 2. Create session PPPoX data socket | ||
|
|
||
| struct sockaddr_pppol2tp sax; | ||
| int fd; | ||
|
|
||
| /* Note, the target socket must be bound already, else it will not be ready */ | ||
| sax.sa_family = AF_PPPOX; | ||
| sax.sa_protocol = PX_PROTO_OL2TP; | ||
| sax.pppol2tp.fd = tunnel_fd; | ||
| sax.pppol2tp.addr.sin_addr.s_addr = addr->sin_addr.s_addr; | ||
| sax.pppol2tp.addr.sin_port = addr->sin_port; | ||
| sax.pppol2tp.addr.sin_family = AF_INET; | ||
| sax.pppol2tp.s_tunnel = tunnel_id; | ||
| sax.pppol2tp.s_session = session_id; | ||
| sax.pppol2tp.d_tunnel = peer_tunnel_id; | ||
| sax.pppol2tp.d_session = peer_session_id; | ||
|
|
||
| /* session_fd is the fd of the session's PPPoL2TP socket. | ||
| * tunnel_fd is the fd of the tunnel UDP socket. | ||
| */ | ||
| fd = connect(session_fd, (struct sockaddr *)&sax, sizeof(sax)); | ||
| if (fd < 0 ) { | ||
| return -errno; | ||
| } | ||
| return 0; | ||
|
|
||
| Miscellanous | ||
| ============ | ||
|
|
||
| The PPPoL2TP driver was developed as part of the OpenL2TP project by | ||
| Katalix Systems Ltd. OpenL2TP is a full-featured L2TP client / server, | ||
| designed from the ground up to have the L2TP datapath in the | ||
| kernel. The project also implemented the pppol2tp plugin for pppd | ||
| which allows pppd to use the kernel driver. Details can be found at | ||
| http://openl2tp.sourceforge.net. |
Oops, something went wrong.