socket.h(3head)

1socket.h(3HEAD)                     Headers                    socket.h(3HEAD)
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NAME

6       socket.h, socket - Internet Protocol family
7

SYNOPSIS

9       #include <sys/socket.h>
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11

DESCRIPTION

13       The  <sys/socket.h>  header  defines the unsigned integral type sa_fam‐
14       ily_t through typedef.
15
16
17       The <sys/socket.h> header defines the sockaddr structure that  includes
18       the following members:
19
20         sa_family_t   sa_family     /* address family */
21         char          sa_data[]     /* socket   address (variable-length
22                                         data) */
23
24
25   libxnet Interfaces
26       The  <sys/socket.h>  header  defines  the  msghdr structure for libxnet
27       interfaces that includes the following members:
28
29         void            *msg_name         /* optional address */
30         socklen_t       msg_namelen       /* size of address */
31         struct iovec    *msg_iov          /* scatter/gather array */
32         int             msg_iovlen        /* members in msg_iov */
33         void            *msg_control      /* ancillary data, see below */
34         socklen_t       msg_controllen    /* ancillary data buffer len */
35         int             msg_flags         /* flags on received message */
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37
38
39       The <sys/socket.h> header defines the  cmsghdr  structure  for  libxnet
40       that includes the following members:
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42         socklen_t  cmsg_len      /* data byte count, including hdr */
43         int        cmsg_level    /* originating protocol */
44         int        cmsg_type     /* protocol-specific type */
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46
47
48       Ancillary  data  consists  of a sequence of pairs, each consisting of a
49       cmsghdr structure followed by a data array. The data array contains the
50       ancillary  data message, and the cmsghdr structure contains descriptive
51       information that allows an application to correctly parse the data.
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54       The values for cmsg_level will be legal values for the  level  argument
55       to  the getsockopt() and setsockopt() functions. The SCM_RIGHTS type is
56       supported for level SOL_SOCKET.
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58
59       Ancillary data is also possible at the socket level. The <sys/socket.h>
60       header  defines  the  following  macros for use as the cmsg_type values
61       when cmsg_level is SOL_SOCKET.
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63       SCM_RIGHTS    Indicates that the data array contains the access  rights
64                     to be sent or received.
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66
67       SCM_UCRED     Indicates  that  the  data array contains a ucred_t to be
68                     received. The ucred_t is the credential  of  the  sending
69                     process  at the time the message was sent. This is a Sun-
70                     specific, Evolving interface. See ucred_get(3C).
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74       The IPv4 data formats generally use the same  values  for  data  passed
75       back  in  cmsghdr  as  for setsockopt() to enable the feature. The IPv4
76       data formats are listed below with the associated payload for each.
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78       IPPROTO_IP
79       IP_RECVDSTADDR
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81           ipaddr_t, IP address
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83
84       IPPROTO_IP
85       IP_RECVOPTS
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87           variable-length IP options, up to 40 bytes
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89
90       IPPROTO_IP
91       IP_RECVIF
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93           uint_t, ifIndex number
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95
96       IPPROTO_IP
97       IP_RECVSLLA
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99           struct sockaddr_dl, link layer address
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101
102       IPPROTO_IP
103       IP_RECVTTL
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105           uint8_t
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107
108       SOL_SOCKET
109       SO_RECVUCRED
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111           ucred_t — cmsghdr.cmsg_type is SCM_UCRED, not SO_RECVUCRED
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114
115       The IPv6 data formats use different values for enabling the option  and
116       for  passing  the  value back to the application. The IPv6 data formats
117       are listed below with the associated payload for each.
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119       IPPROTO_IPV6
120       IPV6_RECVPKTINFO
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122           in_pktinfo, cmsg_type IPV6_PKTINFO
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124
125       IPPROTO_IPV6
126       IPV6_RECVTCLASS
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128           uint_t, cmsg_type IPV6_TCLASS
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130
131       IPPROTO_IPV6
132       IPV6_RECVPATHMTU
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134           ip6_mtuinfo, cmsg_type IPV6_PATHMTU
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136
137       IPPROTO_IPV6
138       IPV6_RECVHOPLIMIT
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140           uint_t, cmsg_type IPV6_HOPLIMIT
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142
143       IPPROTO_IPV6
144       IPV6_RECVHOPOPTS
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146           variable-length IPv6 options, cmsg_type IPV6_HOPOPTS
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148
149       IPPROTO_IPV6
150       IPV6_RECVDSTOPTS
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152           variable-length IPv6 options, cmsg_type IPV6_DSTOPTS
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154
155       IPPROTO_IPV6
156       IPV6_RECVRTHDR
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158           variable-length IPv6 options, cmsg_type IPV6_RTHDR
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160
161       IPPROTO_IPV6
162       IPV6_RECVRTHDRDSTOPTS
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164           variable-length IPv6 options, cmsg_type IPV6_DSTOPTS
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167
168       The <sys/socket.h> header defines the following macros to  gain  access
169       to  the  data  arrays  in  the ancillary data associated with a message
170       header:
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172       CMSG_DATA(cmsg)
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174           If the argument is a pointer to a  cmsghdr  structure,  this  macro
175           returns  an unsigned character pointer to the data array associated
176           with the cmsghdr structure.
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178
179       CMSG_NXTHDR(mhdr, cmsg)
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181           If the first argument is a pointer to a msghdr  structure  and  the
182           second  argument  is a pointer to a cmsghdr structure in the ancil‐
183           lary data, pointed to by  the  msg_control  field  of  that  msghdr
184           structure,  this macro returns a pointer to the next cmsghdr struc‐
185           ture, or a null pointer if this structure is the  last  cmsghdr  in
186           the ancillary data.
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188
189       CMSG_FIRSTHDR(mhdr)
190
191           If  the  argument  is  a  pointer to a msghdr structure, this macro
192           returns a pointer to the first cmsghdr structure in  the  ancillary
193           data  associated  with  this msghdr structure, or a null pointer if
194           there is no ancillary data associated with the msghdr structure.
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196
197       CMSG_SPACE(len)
198
199           Given the length of an ancillary data object, CMSG_SPACE()  returns
200           the space required by the object and its cmsghdr structure, includ‐
201           ing any padding needed  to  satisfy  alignment  requirements.  This
202           macro  can  be used, for example, to allocate space dynamically for
203           the ancillary data. This macro should not be used to initialize the
204           cmsg_len  member  of  a cmsghdr structure. Use the CMSG_LEN() macro
205           instead.
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207
208       CMSG_LEN(len)
209
210           Given the length of an ancillary data  object,  CMSG_LEN()  returns
211           the value to store in the cmsg_len member of the cmsghdr structure,
212           taking  into  account  any  padding  needed  to  satisfy  alignment
213           requirements.
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216
217       The  <sys/socket.h>  header  defines the linger structure that includes
218       the following members:
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220         int   l_onoff   /* indicates  whether  linger option is enabled */
221         int   l_linger  /* linger time, in seconds */
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223
224
225       The <sys/socket.h> header defines the following macros:
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227       SOCK_DGRAM        Datagram socket
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229
230       SOCK_STREAM       Byte-stream socket
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233       SOCK_SEQPACKET    Sequenced-packet socket
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237       The <sys/socket.h> header defines the following macros for use  as  the
238       level argument of setsockopt() and getsockopt().
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240       SOL_SOCKET    Options  to be accessed at the socket level, not the pro‐
241                     tocol level.
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244       SOL_ROUTE     Options to be accessed at the routing socket  level,  not
245                     the protocol level.
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249       The  <sys/socket.h>  header defines the following macros for use as the
250       option_name argument of getsockopt() or setsockopt() calls:
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252       SO_DEBUG         Debugging information is being recorded.
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255       SO_ACCEPTCONN    Socket is accepting connections.
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258       SO_BROADCAST     Transmission of broadcast messages is supported.
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261       SO_REUSEADDR     Reuse of local addresses is supported.
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264       SO_KEEPALIVE     Connections are kept alive with periodic messages.
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267       SO_LINGER        Socket lingers on close.
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270       SO_OOBINLINE     Out-of-band data is transmitted in line.
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273       SO_SNDBUF        Send buffer size.
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276       SO_RCVBUF        Receive buffer size.
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279       SO_ERROR         Socket error status.
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282       SO_TYPE          Socket type.
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285       SO_RECVUCRED     Request the reception  of  user  credential  ancillary
286                        data.  This is a Sun-specific, Evolving interface. See
287                        ucred_get(3C).
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290       SO_MAC_EXEMPT    Mandatory Access Control (MAC) exemption for unlabeled
291                        peers.  This option is available only if the system is
292                        configured with Trusted Extensions.
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295       SO_ALLZONES      Bypass zone boundaries (privileged).
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298
299       The <sys/socket.h> header defines the following macros for use  as  the
300       valid  values  for  the msg_flags field in the msghdr structure, or the
301       flags parameter in recvfrom(), recvmsg(), sendto(), or sendmsg() calls:
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303       MSG_CTRUNC     Control data truncated.
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306       MSG_EOR        Terminates a record (if supported by the protocol).
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309       MSG_OOB        Out-of-band data.
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312       MSG_PEEK       Leave received data in queue.
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315       MSG_TRUNC      Normal data truncated.
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318       MSG_WAITALL    Wait for complete message.
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321
322       The <sys/socket.h> header defines the following macros:
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324       AF_UNIX    UNIX domain sockets
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326
327       AF_INET    Internet domain sockets
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330
331       The <sys/socket.h> header defines the following macros:
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333       SHUT_RD      Disables further receive operations.
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335
336       SHUT_WR      Disables further send operations.
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338
339       SHUT_RDWR    Disables further send and receive operations.
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341
342   libsocket Interfaces
343       The <sys/socket.h> header defines the msghdr  structure  for  libsocket
344       interfaces that includes the following members:
345
346         void           *msg_name        /* optional address */
347         socklen_t      msg_namelen      /* size of address */
348         struct iovec   *msg_iov         /* scatter/gather array */
349         int            msg_iovlen       /* # elements in msg_iov */
350         caddr_t        msg_accrights    /* access rights sent/received */
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354       The msg_name and msg_namelen parameters specify the destination address
355       when the socket is unconnected The msg_name can be specified as a  NULL
356       pointer if no names are desired or required. The msg_iov and msg_iovlen
357       parameters describe  the  scatter-gather  locations,  as  described  in
358       read(2).  The  msg_accrights  parameter  specifies  the buffer in which
359       access  rights  sent  along  with  the  message   are   received.   The
360       msg_accrightslen specifies the length of the buffer.
361

ATTRIBUTES

363       See attributes(5) for descriptions of the following attributes:
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368       ┌─────────────────────────────┬─────────────────────────────┐
369       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
370       ├─────────────────────────────┼─────────────────────────────┤
371       │Interface Stability          │Standard                     │
372       └─────────────────────────────┴─────────────────────────────┘
373

NAME

SYNOPSIS

DESCRIPTION

ATTRIBUTES

SEE ALSO