| natm.4 (116735) | natm.4 (117011) |
|---|---|
| 1.\" $FreeBSD: head/share/man/man4/natm.4 116735 2003-06-23 14:46:12Z harti $ | 1.\" $FreeBSD: head/share/man/man4/natm.4 117011 2003-06-28 23:53:39Z ru $ |
| 2.\" 3.Dd December 29, 1997 4.Dt NATM 4 5.Os 6.Sh NAME 7.Nm natm 8.Nd Native Mode ATM protocol layer 9.Sh DESCRIPTION --- 4 unchanged lines hidden (view full) --- 14which provides socket level access to AAL0 and AAL5 virtual circuits. 15To enable this protocol layer, add 16.Dl options NATM 17to your kernel configuration file and re-make the kernel (don't forget 18to do 19.Dq make clean ) . 20.Sh NATM API 21The NATM layer uses a | 2.\" 3.Dd December 29, 1997 4.Dt NATM 4 5.Os 6.Sh NAME 7.Nm natm 8.Nd Native Mode ATM protocol layer 9.Sh DESCRIPTION --- 4 unchanged lines hidden (view full) --- 14which provides socket level access to AAL0 and AAL5 virtual circuits. 15To enable this protocol layer, add 16.Dl options NATM 17to your kernel configuration file and re-make the kernel (don't forget 18to do 19.Dq make clean ) . 20.Sh NATM API 21The NATM layer uses a |
| 22.Dv struct sockaddr_natm | 22.Vt struct sockaddr_natm |
| 23to specify a virtual circuit: 24.Bd -literal -offset indent 25struct sockaddr_natm { 26 u_int8_t snatm_len; /* length */ 27 u_int8_t snatm_family; /* AF_NATM */ 28 char snatm_if[IFNAMSIZ]; /* interface name */ 29 u_int16_t snatm_vci; /* vci */ 30 u_int8_t snatm_vpi; /* vpi */ --- 16 unchanged lines hidden (view full) --- 47 snatm.snatm_vpi = 0; 48 r = connect(s, (struct sockaddr *)&snatm, sizeof(snatm)); 49 if (r < 0) { perror("connect"); exit(1); } 50 /* s now connected to ATM! */ 51.Ed 52.Pp 53The 54.Fn socket | 23to specify a virtual circuit: 24.Bd -literal -offset indent 25struct sockaddr_natm { 26 u_int8_t snatm_len; /* length */ 27 u_int8_t snatm_family; /* AF_NATM */ 28 char snatm_if[IFNAMSIZ]; /* interface name */ 29 u_int16_t snatm_vci; /* vci */ 30 u_int8_t snatm_vpi; /* vpi */ --- 16 unchanged lines hidden (view full) --- 47 snatm.snatm_vpi = 0; 48 r = connect(s, (struct sockaddr *)&snatm, sizeof(snatm)); 49 if (r < 0) { perror("connect"); exit(1); } 50 /* s now connected to ATM! */ 51.Ed 52.Pp 53The 54.Fn socket |
| 55call simply creates an unconnected NATM socket. The | 55call simply creates an unconnected NATM socket. 56The |
| 56.Fn connect 57call associates an unconnected NATM socket with a 58virtual circuit and tells the driver to enable that virtual circuit | 57.Fn connect 58call associates an unconnected NATM socket with a 59virtual circuit and tells the driver to enable that virtual circuit |
| 59for receiving data. After the | 60for receiving data. 61After the |
| 60.Fn connect 61call one can 62.Fn read 63or 64.Fn write 65to the socket to perform ATM I/O. 66.Sh Internal NATM operation 67Internally, the NATM protocol layer keeps a list of all active virtual 68circuits on the system in 69.Dv natm_pcbs . 70This includes circuits currently being used for IP to prevent NATM and 71IP from clashing over virtual circuit usage. 72.Pp 73When a virtual circuit is enabled for receiving data, the NATM 74protocol layer passes the address of the protocol control block down 75to the driver as a receive 76.Dq handle . 77When inbound data arrives, the driver passes the data back with the | 62.Fn connect 63call one can 64.Fn read 65or 66.Fn write 67to the socket to perform ATM I/O. 68.Sh Internal NATM operation 69Internally, the NATM protocol layer keeps a list of all active virtual 70circuits on the system in 71.Dv natm_pcbs . 72This includes circuits currently being used for IP to prevent NATM and 73IP from clashing over virtual circuit usage. 74.Pp 75When a virtual circuit is enabled for receiving data, the NATM 76protocol layer passes the address of the protocol control block down 77to the driver as a receive 78.Dq handle . 79When inbound data arrives, the driver passes the data back with the |
| 78appropriate receive handle. The NATM layer uses this to avoid the 79overhead of a protocol control block lookup. This allows us to take | 80appropriate receive handle. 81The NATM layer uses this to avoid the 82overhead of a protocol control block lookup. 83This allows us to take |
| 80advantage of the fact that ATM has already demultiplexed the data for 81us. 82.Sh CAVEAT 83The NATM protocol support is subject to change as | 84advantage of the fact that ATM has already demultiplexed the data for 85us. 86.Sh CAVEAT 87The NATM protocol support is subject to change as |
| 84the ATM protocols develop. Users should not depend 85on details of the current implementation, but rather | 88the ATM protocols develop. 89Users should not depend on details of the current implementation, but rather |
| 86the services exported. 87.Sh SEE ALSO 88.Xr en 4 , | 90the services exported. 91.Sh SEE ALSO 92.Xr en 4 , |
| 89.Xr hatm 4 , | |
| 90.Xr fatm 4 , | 93.Xr fatm 4 , |
| 94.Xr hatm 4 , |
|
| 91.Xr natmip 4 92.Sh AUTHORS 93.An Chuck Cranor 94of Washington University implemented the NATM protocol layer 95along with the EN ATM driver in 1996 for 96.Nx . | 95.Xr natmip 4 96.Sh AUTHORS 97.An Chuck Cranor 98of Washington University implemented the NATM protocol layer 99along with the EN ATM driver in 1996 for 100.Nx . |