| sctp_sendmsg.3 (0add3200d178976b95848eff050d419cf4062520) | sctp_sendmsg.3 (d8b5fd91b9011a1c21b7389e2dade6b9b1f6e425) |
|---|---|
| 1.\" Copyright (c) 1983, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. --- 22 unchanged lines hidden (view full) --- 31.\" 32.\" From: @(#)send.2 8.2 (Berkeley) 2/21/94 33.\" $FreeBSD$ 34.\" 35.Dd December 15, 2006 36.Dt SCTP_SENDMSG 3 37.Os 38.Sh NAME | 1.\" Copyright (c) 1983, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. --- 22 unchanged lines hidden (view full) --- 31.\" 32.\" From: @(#)send.2 8.2 (Berkeley) 2/21/94 33.\" $FreeBSD$ 34.\" 35.Dd December 15, 2006 36.Dt SCTP_SENDMSG 3 37.Os 38.Sh NAME |
| 39.Nm sctp_sendmsg , | 39.Nm sctp_sendmsg |
| 40.Nm sctp_sendmsgx 41.Nd send a message from an SCTP socket 42.Sh LIBRARY 43.Lb libc 44.Sh SYNOPSIS 45.In sys/types.h 46.In sys/socket.h | 40.Nm sctp_sendmsgx 41.Nd send a message from an SCTP socket 42.Sh LIBRARY 43.Lb libc 44.Sh SYNOPSIS 45.In sys/types.h 46.In sys/socket.h |
| 47.In netinet/sctp.h | 47.In sys/sctp.h |
| 48.Ft ssize_t | 48.Ft ssize_t |
| 49.Fo sctp_sendmsg 50.Fa "int s" "const void *msg" "size_t len" "const struct sockaddr *to" 51.Fa "socklen_t tolen" "uint32_t ppid" "uint32_t flags" "uint16_t stream_no" 52.Fa "uint32_t timetolive" "uint32_t context" 53.Fc | 49.Fn sctp_sendmsg "int s" "const void *msg" "size_t len" "const struct sockaddr *to" "socklen_t tolen" "uint32_t ppid" "uint32_t flags" "uint16_t stream_no" "uint32_t timetolive" "uint32_t context" |
| 54.Ft ssize_t | 50.Ft ssize_t |
| 55.Fo sctp_sendmsgx 56.Fa "int s" "const void *msg" "size_t len" "const struct sockaddr *to" 57.Fa "int addrcnt" "uint32_t ppid" "uint32_t flags" "uint16_t stream_no" 58.Fa "uint32_t timetolive" "uint32_t context" 59.Fc | 51.Fn sctp_sendmsgx "int s" "const void *msg" "size_t len" "const struct sockaddr *to" "int addrcnt" "uint32_t ppid" "uint32_t flags" "uint16_t stream_no" "uint32_t timetolive" "uint32_t context" 52 |
| 60.Sh DESCRIPTION 61The 62.Fn sctp_sendmsg | 53.Sh DESCRIPTION 54The 55.Fn sctp_sendmsg |
| 63system call | 56system calls |
| 64is used to transmit a message to another SCTP endpoint. 65The 66.Fn sctp_sendmsg | 57is used to transmit a message to another SCTP endpoint. 58The 59.Fn sctp_sendmsg |
| 67may be used at any time. 68If the socket is a one-to-many type (SOCK_SEQPACKET) | 60may be used at any time. If the socket is a one-to-many type (SOCK_SEQPACKET) |
| 69socket then an attempt to send to an address that no association exists to will | 61socket then an attempt to send to an address that no association exists to will |
| 70implicitly create a new association. 71Data sent in such an instance will result in 72the data being sent on the third leg of the SCTP four-way handshake. 73Note that if | 62implicitly create a new association. Data sent in such an instance will result in 63the data being sent on the third leg of the SCTP four-way handshake. Note that if |
| 74the socket is a one-to-one type (SOCK_STREAM) socket then an association must 75be in existance (by use of the | 64the socket is a one-to-one type (SOCK_STREAM) socket then an association must 65be in existance (by use of the |
| 76.Xr connect 2 77system call). 78Calling | 66.Fn connect 2 67system call). Calling |
| 79.Fn sctp_sendmsg 80or 81.Fn sctp_sendmsgx | 68.Fn sctp_sendmsg 69or 70.Fn sctp_sendmsgx |
| 82on a non-connected one-to-one socket will result in 83.Va errno 84being set to 85.Er ENOTCONN , 86-1 being returned, and the message not being transmitted. | 71on a non-connected one-to-one socket will result in the errno being set to 72.Er ENOTCONN 73a -1 being returned, and the message is not transmitted. |
| 87.Pp 88The address of the target is given by 89.Fa to 90with 91.Fa tolen 92specifying its size. 93The length of the message 94.Fa msg 95is given by 96.Fa len . 97If the message is too long to pass atomically through the | 74.Pp 75The address of the target is given by 76.Fa to 77with 78.Fa tolen 79specifying its size. 80The length of the message 81.Fa msg 82is given by 83.Fa len . 84If the message is too long to pass atomically through the |
| 98underlying protocol, 99.Va errno 100is set to 101.Er EMSGSIZE , 102-1 is returned, and | 85underlying protocol, the errno is set to 86.Er EMSGSIZE 87a -1 is returned, and |
| 103the message is not transmitted. 104.Pp 105No indication of failure to deliver is implicit in a | 88the message is not transmitted. 89.Pp 90No indication of failure to deliver is implicit in a |
| 106.Xr sctp_sendmsg 3 107call. | 91.Fn sctp_sendmsg 2 |
| 108Locally detected errors are indicated by a return value of -1. 109.Pp | 92Locally detected errors are indicated by a return value of -1. 93.Pp |
| 110If no space is available at the socket to hold | 94If no messages space is available at the socket to hold |
| 111the message to be transmitted, then | 95the message to be transmitted, then |
| 112.Xr sctp_sendmsg 3 | 96.Fn sctp_sendmsg 2 |
| 113normally blocks, unless the socket has been placed in 114non-blocking I/O mode. 115The | 97normally blocks, unless the socket has been placed in 98non-blocking I/O mode. 99The |
| 116.Xr select 2 | 100.Fn select 2 |
| 117system call may be used to determine when it is possible to 118send more data on one-to-one type (SOCK_STREAM) sockets. 119.Pp 120The 121.Fa ppid 122argument is an opaque 32 bit value that is passed transparently | 101system call may be used to determine when it is possible to 102send more data on one-to-one type (SOCK_STREAM) sockets. 103.Pp 104The 105.Fa ppid 106argument is an opaque 32 bit value that is passed transparently |
| 123through the stack to the peer endpoint. 124It will be available on | 107through the stack to the peer endpoint. It will be available on |
| 125reception of a message (see | 108reception of a message (see |
| 126.Xr sctp_recvmsg 3 ) . 127Note that the stack passes this value without regard to byte | 109.Fn sctp_recvmsg 2 110). Note that the stack passes this value without regard to byte |
| 128order. 129.Pp 130The 131.Fa flags 132argument may include one or more of the following: 133.Bd -literal 134#define SCTP_EOF 0x0100 /* Start a shutdown procedures */ 135#define SCTP_ABORT 0x0200 /* Send an ABORT to peer */ --- 5 unchanged lines hidden (view full) --- 141#define SCTP_PR_SCTP_TTL 0x0001 /* Time based PR-SCTP */ 142#define SCTP_PR_SCTP_BUF 0x0002 /* Buffer based PR-SCTP */ 143#define SCTP_PR_SCTP_RTX 0x0003 /* Number of retransmissions based PR-SCTP */ 144.Ed 145.Pp 146The flag 147.Dv SCTP_EOF 148is used to instruct the SCTP stack to queue this message | 111order. 112.Pp 113The 114.Fa flags 115argument may include one or more of the following: 116.Bd -literal 117#define SCTP_EOF 0x0100 /* Start a shutdown procedures */ 118#define SCTP_ABORT 0x0200 /* Send an ABORT to peer */ --- 5 unchanged lines hidden (view full) --- 124#define SCTP_PR_SCTP_TTL 0x0001 /* Time based PR-SCTP */ 125#define SCTP_PR_SCTP_BUF 0x0002 /* Buffer based PR-SCTP */ 126#define SCTP_PR_SCTP_RTX 0x0003 /* Number of retransmissions based PR-SCTP */ 127.Ed 128.Pp 129The flag 130.Dv SCTP_EOF 131is used to instruct the SCTP stack to queue this message |
| 149and then start a graceful shutdown of the association. 150All | 132and then start a graceful shutdown of the association. All |
| 151remaining data in queue will be sent after which the association | 133remaining data in queue will be sent after which the association |
| 152will be shut down. | 134will be shutdown. |
| 153.Pp 154.Dv SCTP_ABORT | 135.Pp 136.Dv SCTP_ABORT |
| 155is used to immediately terminate an association. 156An abort | 137is used to immediately terminate an association. An abort |
| 157is sent to the peer and the local TCB is destroyed. 158.Pp 159.Dv SCTP_UNORDERED 160is used to specify that the message being sent has no 161specific order and should be delivered to the peer application | 138is sent to the peer and the local TCB is destroyed. 139.Pp 140.Dv SCTP_UNORDERED 141is used to specify that the message being sent has no 142specific order and should be delivered to the peer application |
| 162as soon as possible. 163When this flag is absent messages | 143as soon as possible. When this flag is absent messages |
| 164are delivered in order within the stream they are sent, but without 165respect to order to peer streams. 166.Pp 167The flag 168.Dv SCTP_ADDR_OVER | 144are delivered in order within the stream they are sent, but without 145respect to order to peer streams. 146.Pp 147The flag 148.Dv SCTP_ADDR_OVER |
| 169is used to specify that an specific address should be used. 170Normally 171SCTP will use only one of a multi-homed peers addresses as the primary 172address to send to. 173By default, no matter what the | 149is used to specify that an specific address should be used. Normally 150SCTP will use only one of a multi-homed peers address as the primary 151address to send to. By default, no matter what the |
| 174.Fa to | 152.Fa to |
| 175argument is, this primary address is used to send data. 176By specifying | 153argument is, this primary address is used to send data. By specifying |
| 177this flag, the user is asking the stack to ignore the primary address | 154this flag, the user is asking the stack to ignore the primary address |
| 178and instead use the specified address not only as a lookup mechanism 179to find the association but also as the actual address to send to. | 155and instead use the specified address not only has a lookup mechanism 156to find the association but also has the actual address to send to. |
| 180.Pp 181For a one-to-many type (SOCK_SEQPACKET) socket the flag 182.Dv SCTP_SENDALL 183can be used as a convient way to make one send call and have 184all associations that are under the socket get a copy of the message. 185Note that this mechanism is quite efficent and makes only one actual 186copy of the data which is shared by all the associations for sending. 187.Pp | 157.Pp 158For a one-to-many type (SOCK_SEQPACKET) socket the flag 159.Dv SCTP_SENDALL 160can be used as a convient way to make one send call and have 161all associations that are under the socket get a copy of the message. 162Note that this mechanism is quite efficent and makes only one actual 163copy of the data which is shared by all the associations for sending. 164.Pp |
| 188The remaining flags are used for the partial reliability extension (RFC3758) | 165The remaining flags are used for the partial reliabilty extension (RFC3758) |
| 189and will only be effective if the peer endpoint supports this extension. | 166and will only be effective if the peer endpoint supports this extension. |
| 190This option specifies what local policy the local endpoint should use 191in skipping data. 192If none of these options are set, then data is | 167This option specify's what local policy the local endpoint should use 168in skipping data. If none of these options are set, then data is |
| 193never skipped over. 194.Pp 195.Dv SCTP_PR_SCTP_TTL | 169never skipped over. 170.Pp 171.Dv SCTP_PR_SCTP_TTL |
| 196is used to indicate that a time based lifetime is being applied 197to the data. 198The | 172Is used to indicate that a time based lifetime is being applied 173to the data. The |
| 199.Fa timetolive 200argument is then a number of milliseconds for which the data is | 174.Fa timetolive 175argument is then a number of milliseconds for which the data is |
| 201attempted to be transmitted. 202If that many milliseconds ellapse 203and the peer has not acknowledged the data, the data will be 204skipped and no longer transmitted. 205Note that this policy does 206not even assure that the data will ever be sent. 207In times of a congestion | 176attempted to be transmitted. If that many milliseconds ellapses 177and the peer has not acknowledge the data, the data will be 178skipped and no longer transmitted. Note that this policy does 179not even assure that the data will ever be sent. In times of a congestion |
| 208with large amounts of data being queued, the 209.Fa timetolive 210may expire before the first transmission is ever made. 211.Pp 212The 213.Dv SCTP_PR_SCTP_BUF 214based policy transforms the 215.Fa timetolive 216field into a total number of bytes allowed on the outbound | 180with large amounts of data being queued, the 181.Fa timetolive 182may expire before the first transmission is ever made. 183.Pp 184The 185.Dv SCTP_PR_SCTP_BUF 186based policy transforms the 187.Fa timetolive 188field into a total number of bytes allowed on the outbound |
| 217send queue. 218If that number or more bytes are in queue, then | 189send queue. If that number or more bytes are in queue, then |
| 219other buffer based sends are looked to be removed and | 190other buffer based sends are looked to be removed and |
| 220skipped. 221Note that this policy may also result in the data | 191skipped. Note that this policy may also result in the data |
| 222never being sent if no buffer based sends are in queue and 223the maximum specified by 224.Fa timetolive 225bytes is in queue. 226.Pp 227The 228.Dv SCTP_PR_SCTP_RTX 229policy transforms the 230.Fa timetolive | 192never being sent if no buffer based sends are in queue and 193the maximum specified by 194.Fa timetolive 195bytes is in queue. 196.Pp 197The 198.Dv SCTP_PR_SCTP_RTX 199policy transforms the 200.Fa timetolive |
| 231into a number of retransmissions to allow. 232This policy | 201into a number of retransmissions to allow. This policy |
| 233always assures that at a minimum one send attempt is | 202always assures that at a minimum one send attempt is |
| 234made of the data. 235After which no more than | 203made of the data. After which no more than |
| 236.Fa timetolive 237retransmissions will be made before the data is skipped. 238.Pp 239.Fa stream_no 240is the SCTP stream that you wish to send the | 204.Fa timetolive 205retransmissions will be made before the data is skipped. 206.Pp 207.Fa stream_no 208is the SCTP stream that you wish to send the |
| 241message on. 242Streams in SCTP are reliable (or partially reliable) flows of ordered 243messages. 244The | 209message on. Streams in SCTP are reliable (or partially reliable) flows of ordered 210messages. The |
| 245.Fa context | 211.Fa context |
| 246field is used only in the event the message cannot be sent. 247This is an opaque | 212field is used only in the event the message cannot be sent. This is an opaque |
| 248value that the stack retains and will give to the user when a failed send 249is given if that notification is enabled (see | 213value that the stack retains and will give to the user when a failed send 214is given if that notification is enabled (see |
| 250.Xr sctp 4 ) . 251Normally a user process can use this value to index some application | 215.Tn sctp 216). Normally a user process can use this value to index some application |
| 252specific data structure when a send cannot be fulfilled. 253.Fn sctp_sendmsgx 254is identical to 255.Fn sctp_sendmsg | 217specific data structure when a send cannot be fulfilled. 218.Fn sctp_sendmsgx 219is identical to 220.Fn sctp_sendmsg |
| 256with the exception that it takes an array of sockaddr structures in the | 221with the exception that it takes a array of sockaddr structures in the |
| 257argument 258.Fa to 259and adds the additional argument 260.Fa addrcnt | 222argument 223.Fa to 224and adds the additional argument 225.Fa addrcnt |
| 261which specifies how many addresses are in the array. 262This allows a 263caller to implicitly set up an association passing multiple addresses 264as if | 226which specifies how many addresses are in the array. This allows a 227caller to implictly setup an association passing multiple addresses 228as if an |
| 265.Fn sctp_connectx | 229.Fn sctp_connectx |
| 266had been called to set up the association. | 230had been called to setup the association. |
| 267.Sh RETURN VALUES 268The call returns the number of characters sent, or -1 269if an error occurred. 270.Sh ERRORS 271The | 231.Sh RETURN VALUES 232The call returns the number of characters sent, or -1 233if an error occurred. 234.Sh ERRORS 235The |
| 272.Fn sctp_sendmsg | 236.Fn sctp_sendmsg 2 |
| 273system call | 237system call |
| 274fails if: | 238fail if: |
| 275.Bl -tag -width Er 276.It Bq Er EBADF 277An invalid descriptor was specified. 278.It Bq Er ENOTSOCK 279The argument 280.Fa s 281is not a socket. 282.It Bq Er EFAULT --- 8 unchanged lines hidden (view full) --- 291The system was unable to allocate an internal buffer. 292The operation may succeed when buffers become available. 293.It Bq Er ENOBUFS 294The output queue for a network interface was full. 295This generally indicates that the interface has stopped sending, 296but may be caused by transient congestion. 297.It Bq Er EHOSTUNREACH 298The remote host was unreachable. | 239.Bl -tag -width Er 240.It Bq Er EBADF 241An invalid descriptor was specified. 242.It Bq Er ENOTSOCK 243The argument 244.Fa s 245is not a socket. 246.It Bq Er EFAULT --- 8 unchanged lines hidden (view full) --- 255The system was unable to allocate an internal buffer. 256The operation may succeed when buffers become available. 257.It Bq Er ENOBUFS 258The output queue for a network interface was full. 259This generally indicates that the interface has stopped sending, 260but may be caused by transient congestion. 261.It Bq Er EHOSTUNREACH 262The remote host was unreachable. |
| 299.It Bq Er ENOTCONN 300On a one-to-one style socket no association exists. | 263.It Bq Er ENOTCON 264On a one to one style socket no association exists. |
| 301.It Bq Er ECONNRESET 302An abort was received by the stack while the user was 303attempting to send data to the peer. 304.It Bq Er ENOENT | 265.It Bq Er ECONNRESET 266An abort was received by the stack while the user was 267attempting to send data to the peer. 268.It Bq Er ENOENT |
| 305On a one-to-many style socket no address is specified | 269On a one to many style socket no address is specified |
| 306so that the association cannot be located or the | 270so that the association cannot be located or the |
| 307.Dv SCTP_ABORT 308flag was specified on a non-existing association. | 271SCTP_ABORT flag was specified on a non-existing association. |
| 309.It Bq Er EPIPE 310The socket is unable to send anymore data 311.Dv ( SBS_CANTSENDMORE 312has been set on the socket). 313This typically means that the socket 314is not connected and is a one-to-one style socket. 315.El 316.Sh SEE ALSO | 272.It Bq Er EPIPE 273The socket is unable to send anymore data 274.Dv ( SBS_CANTSENDMORE 275has been set on the socket). 276This typically means that the socket 277is not connected and is a one-to-one style socket. 278.El 279.Sh SEE ALSO |
| 280.Xr sctp 4 , 281.Xr sendmsg 3 , |
|
| 317.Xr connect 2 , | 282.Xr connect 2 , |
| 283.Xr sctp_connectx 3 , |
|
| 318.Xr getsockopt 2 , 319.Xr recv 2 , 320.Xr select 2 , 321.Xr socket 2 , | 284.Xr getsockopt 2 , 285.Xr recv 2 , 286.Xr select 2 , 287.Xr socket 2 , |
| 322.Xr write 2 , 323.Xr sctp_connectx 3 , 324.Xr sendmsg 3 , 325.Xr sctp 4 | 288.Xr write 2 |
| 326.Sh BUGS | 289.Sh BUGS |
| 327Because in the one-to-many style socket | 290Because in the one-to-many style socket the |
| 328.Fn sctp_sendmsg 329or 330.Fn sctp_sendmsgx 331may have multiple associations under one endpoint, a 332select on write will only work for a one-to-one style 333socket. | 291.Fn sctp_sendmsg 292or 293.Fn sctp_sendmsgx 294may have multiple associations under one endpoint, a 295select on write will only work for a one-to-one style 296socket. |
| 297 |
|