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diff --git a/static/netbsd/man4/ip6.4 3.html b/static/netbsd/man4/ip6.4 3.html deleted file mode 100644 index b869b739..00000000 --- a/static/netbsd/man4/ip6.4 3.html +++ /dev/null @@ -1,561 +0,0 @@ -<table class="head"> - <tr> - <td class="head-ltitle">IP6(4)</td> - <td class="head-vol">Device Drivers Manual</td> - <td class="head-rtitle">IP6(4)</td> - </tr> -</table> -<div class="manual-text"> -<section class="Sh"> -<h1 class="Sh" id="NAME"><a class="permalink" href="#NAME">NAME</a></h1> -<p class="Pp"><code class="Nm">ip6</code> — <span class="Nd">Internet - Protocol version 6 (IPv6) network layer</span></p> -</section> -<section class="Sh"> -<h1 class="Sh" id="SYNOPSIS"><a class="permalink" href="#SYNOPSIS">SYNOPSIS</a></h1> -<p class="Pp"><code class="In">#include - <<a class="In">sys/socket.h</a>></code> - <br/> - <code class="In">#include <<a class="In">netinet/in.h</a>></code></p> -<p class="Pp"><var class="Ft">int</var> - <br/> - <code class="Fn">socket</code>(<var class="Fa" style="white-space: nowrap;">AF_INET6</var>, - <var class="Fa" style="white-space: nowrap;">SOCK_RAW</var>, - <var class="Fa" style="white-space: nowrap;">proto</var>);</p> -</section> -<section class="Sh"> -<h1 class="Sh" id="DESCRIPTION"><a class="permalink" href="#DESCRIPTION">DESCRIPTION</a></h1> -<p class="Pp">The IPv6 network layer is used by the IPv6 protocol family for - transporting data. IPv6 packets contain an IPv6 header that is not provided - as part of the payload contents when passed to an application. IPv6 header - options affect the behavior of this protocol and may be used by high-level - protocols (such as the <a class="Xr">tcp(4)</a> and <a class="Xr">udp(4)</a> - protocols) as well as directly by “raw sockets”, which process - IPv6 messages at a lower-level and may be useful for developing new - protocols and special-purpose applications.</p> -<section class="Ss"> -<h2 class="Ss" id="Header"><a class="permalink" href="#Header">Header</a></h2> -<p class="Pp">All IPv6 packets begin with an IPv6 header. When data received by - the kernel are passed to the application, this header is not included in - buffer, even when raw sockets are being used. Likewise, when data are sent - to the kernel for transmit from the application, the buffer is not examined - for an IPv6 header: the kernel always constructs the header. To directly - access IPv6 headers from received packets and specify them as part of the - buffer passed to the kernel, link-level access (<a class="Xr">bpf(4)</a>, - for example) must be used instead.</p> -<p class="Pp">The header has the following definition:</p> -<div class="Bd Pp Bd-indent Li"> -<pre>struct ip6_hdr { - union { - struct ip6_hdrctl { - uint32_t ip6_un1_flow; /* 20 bits of flow ID */ - uint16_t ip6_un1_plen; /* payload length */ - uint8_t ip6_un1_nxt; /* next header */ - uint8_t ip6_un1_hlim; /* hop limit */ - } ip6_un1; - uint8_t ip6_un2_vfc; /* version and class */ - } ip6_ctlun; - struct in6_addr ip6_src; /* source address */ - struct in6_addr ip6_dst; /* destination address */ -} __packed; - -#define ip6_vfc ip6_ctlun.ip6_un2_vfc -#define ip6_flow ip6_ctlun.ip6_un1.ip6_un1_flow -#define ip6_plen ip6_ctlun.ip6_un1.ip6_un1_plen -#define ip6_nxt ip6_ctlun.ip6_un1.ip6_un1_nxt -#define ip6_hlim ip6_ctlun.ip6_un1.ip6_un1_hlim -#define ip6_hops ip6_ctlun.ip6_un1.ip6_un1_hlim</pre> -</div> -<p class="Pp">All fields are in network-byte order. Any options specified (see - <a class="Sx" href="#Options">Options</a> below) must also be specified in - network-byte order.</p> -<p class="Pp"><var class="Va">ip6_flow</var> specifies the flow ID. - <var class="Va">ip6_plen</var> specifies the payload length. - <var class="Va">ip6_nxt</var> specifies the type of the next header. - <var class="Va">ip6_hlim</var> specifies the hop limit.</p> -<p class="Pp">The top 4 bits of <var class="Va">ip6_vfc</var> specify the class - and the bottom 4 bits specify the version.</p> -<p class="Pp"><var class="Va">ip6_src</var> and <var class="Va">ip6_dst</var> - specify the source and destination addresses.</p> -<p class="Pp">The IPv6 header may be followed by any number of extension headers - that start with the following generic definition:</p> -<div class="Bd Pp Bd-indent Li"> -<pre>struct ip6_ext { - uint8_t ip6e_nxt; - uint8_t ip6e_len; -} __packed;</pre> -</div> -</section> -<section class="Ss"> -<h2 class="Ss" id="Options"><a class="permalink" href="#Options">Options</a></h2> -<p class="Pp">IPv6 allows header options on packets to manipulate the behavior - of the protocol. These options and other control requests are accessed with - the <a class="Xr">getsockopt(2)</a> and <a class="Xr">setsockopt(2)</a> - system calls at level <code class="Dv">IPPROTO_IPV6</code> and by using - ancillary data in <a class="Xr">recvmsg(2)</a> and - <a class="Xr">sendmsg(2)</a>. They can be used to access most of the fields - in the IPv6 header and extension headers.</p> -<p class="Pp">The following socket options are supported:</p> -<dl class="Bl-tag"> - <dt id="IPV6_UNICAST_HOPS"><a class="permalink" href="#IPV6_UNICAST_HOPS"><code class="Dv">IPV6_UNICAST_HOPS</code></a> - <var class="Fa">int *</var></dt> - <dd>Get or set the default hop limit header field for outgoing unicast - datagrams sent on this socket. A value of -1 resets to the default - value.</dd> - <dt id="IPV6_MULTICAST_IF"><a class="permalink" href="#IPV6_MULTICAST_IF"><code class="Dv">IPV6_MULTICAST_IF</code></a> - <var class="Fa">u_int *</var></dt> - <dd>Get or set the interface from which multicast packets will be sent. For - hosts with multiple interfaces, each multicast transmission is sent from - the primary network interface. The interface is specified as its index as - provided by <a class="Xr">if_nametoindex(3)</a>. A value of zero specifies - the default interface.</dd> - <dt id="IPV6_MULTICAST_HOPS"><a class="permalink" href="#IPV6_MULTICAST_HOPS"><code class="Dv">IPV6_MULTICAST_HOPS</code></a> - <var class="Fa">int *</var></dt> - <dd>Get or set the default hop limit header field for outgoing multicast - datagrams sent on this socket. This option controls the scope of multicast - datagram transmissions. - <p class="Pp">Datagrams with a hop limit of 1 are not forwarded beyond the - local network. Multicast datagrams with a hop limit of zero will not be - transmitted on any network but may be delivered locally if the sending - host belongs to the destination group and if multicast loopback (see - below) has not been disabled on the sending socket. Multicast datagrams - with a hop limit greater than 1 may be forwarded to the other networks - if a multicast router (such as <a class="Xr">mrouted(8)</a>) is attached - to the local network.</p> - </dd> - <dt id="IPV6_MULTICAST_LOOP"><a class="permalink" href="#IPV6_MULTICAST_LOOP"><code class="Dv">IPV6_MULTICAST_LOOP</code></a> - <var class="Fa">u_int *</var></dt> - <dd>Get or set the status of whether multicast datagrams will be looped back - for local delivery when a multicast datagram is sent to a group to which - the sending host belongs. - <p class="Pp">This option improves performance for applications that may - have no more than one instance on a single host (such as a router - daemon) by eliminating the overhead of receiving their own - transmissions. It should generally not be used by applications for which - there may be more than one instance on a single host (such as a - conferencing program) or for which the sender does not belong to the - destination group (such as a time-querying program).</p> - <p class="Pp">A multicast datagram sent with an initial hop limit greater - than 1 may be delivered to the sending host on a different interface - from that on which it was sent if the host belongs to the destination - group on that other interface. The multicast loopback control option has - no effect on such delivery.</p> - </dd> - <dt id="IPV6_JOIN_GROUP"><a class="permalink" href="#IPV6_JOIN_GROUP"><code class="Dv">IPV6_JOIN_GROUP</code></a> - <var class="Fa">struct ipv6_mreq *</var></dt> - <dd>Join a multicast group. A host must become a member of a multicast group - before it can receive datagrams sent to the group. - <div class="Bd Pp Li"> - <pre>struct ipv6_mreq { - struct in6_addr ipv6mr_multiaddr; - unsigned int ipv6mr_interface; -};</pre> - </div> - <p class="Pp"><var class="Va">ipv6mr_interface</var> may be set to zeroes to - choose the default multicast interface or to the index of a particular - multicast-capable interface if the host is multihomed. Membership is - associated with a single interface; programs running on multihomed hosts - may need to join the same group on more than one interface.</p> - <p class="Pp">If the multicast address is unspecified (i.e., all zeroes), - messages from all multicast addresses will be accepted by this group. - Note that setting to this value requires superuser privileges.</p> - </dd> - <dt id="IPV6_LEAVE_GROUP"><a class="permalink" href="#IPV6_LEAVE_GROUP"><code class="Dv">IPV6_LEAVE_GROUP</code></a> - <var class="Fa">struct ipv6_mreq *</var></dt> - <dd>Drop membership from the associated multicast group. Memberships are - automatically dropped when the socket is closed or when the process - exits.</dd> - <dt id="IPV6_IPSEC_POLICY"><a class="permalink" href="#IPV6_IPSEC_POLICY"><code class="Dv">IPV6_IPSEC_POLICY</code></a> - <var class="Fa">struct sadb_x_policy *</var></dt> - <dd>Get or set IPSec policy for sockets. For example, - <div class="Bd Pp Li"> - <pre>const char *policy = "in ipsec ah/transport//require"; -char *buf = ipsec_set_policy(policy, strlen(policy)); -setsockopt(s, IPPROTO_IPV6, IPV6_IPSEC_POLICY, buf, ipsec_get_policylen(buf));</pre> - </div> - </dd> - <dt id="IPV6_PORTALGO"><a class="permalink" href="#IPV6_PORTALGO"><code class="Dv">IPV6_PORTALGO</code></a> - <var class="Fa">int *</var></dt> - <dd>The <code class="Dv">IP_PORTALGO</code> can be used to randomize the port - selection. Valid algorithms are described in <a class="Xr">rfc6056(7)</a> - and their respective constants are in - <code class="In"><<a class="In">netinet/portalgo.h</a>></code>. For - example, - <div class="Bd Pp Li"> - <pre>int algo = PORTALGO_ALGO_RANDOM_PICK; /* see <netinet/portalgo.h> */ -setsockopt(s, IPPROTO_IPV6, IPV6_PORTALGO, &algo, sizeof(algo));</pre> - </div> - <p class="Pp">The port selection can be also viewed and controlled at a - global level for all IPV6 sockets using the following - <a class="Xr">sysctl(7)</a> variables: - <code class="Dv">net.inet6.ip6.anonportalgo.available</code> and - <code class="Dv">net.inet6.ip6.anonportalgo.selected</code>.</p> - </dd> - <dt id="IPV6_PORTRANGE"><a class="permalink" href="#IPV6_PORTRANGE"><code class="Dv">IPV6_PORTRANGE</code></a> - <var class="Fa">int *</var></dt> - <dd>Get or set the allocation policy of ephemeral ports for when the kernel - automatically binds a local address to this socket. The following values - are available: - <p class="Pp"></p> - <dl class="Bl-tag Bl-compact"> - <dt id="IPV6_PORTRANGE_DEFAULT"><a class="permalink" href="#IPV6_PORTRANGE_DEFAULT"><code class="Dv">IPV6_PORTRANGE_DEFAULT</code></a></dt> - <dd>Use the regular range of non-reserved ports (varies, see - <a class="Xr">sysctl(8)</a>).</dd> - <dt id="IPV6_PORTRANGE_HIGH"><a class="permalink" href="#IPV6_PORTRANGE_HIGH"><code class="Dv">IPV6_PORTRANGE_HIGH</code></a></dt> - <dd>Use a high range (varies, see <a class="Xr">sysctl(8)</a>).</dd> - <dt id="IPV6_PORTRANGE_LOW"><a class="permalink" href="#IPV6_PORTRANGE_LOW"><code class="Dv">IPV6_PORTRANGE_LOW</code></a></dt> - <dd>Use a low, reserved range (600-1023).</dd> - </dl> - </dd> - <dt id="IPV6_PKTINFO"><a class="permalink" href="#IPV6_PKTINFO"><code class="Dv">IPV6_PKTINFO</code></a> - <var class="Fa">int *</var></dt> - <dd>Get or set whether additional information about subsequent packets will be - provided as ancillary data along with the payload in subsequent - <a class="Xr">recvmsg(2)</a> calls. The information is stored in the - following structure in the ancillary data returned: - <div class="Bd Pp Li"> - <pre>struct in6_pktinfo { - struct in6_addr ipi6_addr; /* src/dst IPv6 address */ - unsigned int ipi6_ifindex; /* send/recv if index */ -};</pre> - </div> - </dd> - <dt id="IPV6_HOPLIMIT"><a class="permalink" href="#IPV6_HOPLIMIT"><code class="Dv">IPV6_HOPLIMIT</code></a> - <var class="Fa">int *</var></dt> - <dd>Get or set whether the hop limit header field from subsequent packets will - be provided as ancillary data along with the payload in subsequent - <a class="Xr">recvmsg(2)</a> calls. The value is stored as an - <var class="Vt">int</var> in the ancillary data returned.</dd> - <dt id="IPV6_HOPOPTS"><a class="permalink" href="#IPV6_HOPOPTS"><code class="Dv">IPV6_HOPOPTS</code></a> - <var class="Fa">int *</var></dt> - <dd>Get or set whether the hop-by-hop options from subsequent packets will be - provided as ancillary data along with the payload in subsequent - <a class="Xr">recvmsg(2)</a> calls. The option is stored in the following - structure in the ancillary data returned: - <div class="Bd Pp Li"> - <pre>struct ip6_hbh { - uint8_t ip6h_nxt; /* next header */ - uint8_t ip6h_len; /* length in units of 8 octets */ -/* followed by options */ -} __packed;</pre> - </div> - <p class="Pp" id="inet6_option_space">The - <a class="permalink" href="#inet6_option_space"><code class="Fn">inet6_option_space</code></a>() - routine and family of routines may be used to manipulate this data.</p> - <p class="Pp">This option requires superuser privileges.</p> - </dd> - <dt id="IPV6_DSTOPTS"><a class="permalink" href="#IPV6_DSTOPTS"><code class="Dv">IPV6_DSTOPTS</code></a> - <var class="Fa">int *</var></dt> - <dd>Get or set whether the destination options from subsequent packets will be - provided as ancillary data along with the payload in subsequent - <a class="Xr">recvmsg(2)</a> calls. The option is stored in the following - structure in the ancillary data returned: - <div class="Bd Pp Li"> - <pre>struct ip6_dest { - uint8_t ip6d_nxt; /* next header */ - uint8_t ip6d_len; /* length in units of 8 octets */ -/* followed by options */ -} __packed;</pre> - </div> - <p class="Pp" id="inet6_option_space~2">The - <a class="permalink" href="#inet6_option_space~2"><code class="Fn">inet6_option_space</code></a>() - routine and family of routines may be used to manipulate this data.</p> - <p class="Pp">This option requires superuser privileges.</p> - </dd> - <dt id="IPV6_RTHDR"><a class="permalink" href="#IPV6_RTHDR"><code class="Dv">IPV6_RTHDR</code></a> - <var class="Fa">int *</var></dt> - <dd>Get or set whether the routing header from subsequent packets will be - provided as ancillary data along with the payload in subsequent - <a class="Xr">recvmsg(2)</a> calls. The header is stored in the following - structure in the ancillary data returned: - <div class="Bd Pp Li"> - <pre>struct ip6_rthdr { - uint8_t ip6r_nxt; /* next header */ - uint8_t ip6r_len; /* length in units of 8 octets */ - uint8_t ip6r_type; /* routing type */ - uint8_t ip6r_segleft; /* segments left */ -/* followed by routing-type-specific data */ -} __packed;</pre> - </div> - <p class="Pp" id="inet6_option_space~3">The - <a class="permalink" href="#inet6_option_space~3"><code class="Fn">inet6_option_space</code></a>() - routine and family of routines may be used to manipulate this data.</p> - <p class="Pp">This option requires superuser privileges.</p> - </dd> - <dt id="IPV6_PKTOPTIONS"><a class="permalink" href="#IPV6_PKTOPTIONS"><code class="Dv">IPV6_PKTOPTIONS</code></a> - <var class="Fa">struct cmsghdr *</var></dt> - <dd>Get or set all header options and extension headers at one time on the - last packet sent or received on the socket. All options must fit within - the size of an mbuf (see <a class="Xr">mbuf(9)</a>). Options are specified - as a series of <var class="Vt">cmsghdr</var> structures followed by - corresponding values. <var class="Va">cmsg_level</var> is set to - <code class="Dv">IPPROTO_IPV6</code>, <var class="Va">cmsg_type</var> to - one of the other values in this list, and trailing data to the option - value. When setting options, if the length <var class="Va">optlen</var> to - <a class="Xr">setsockopt(2)</a> is zero, all header options will be reset - to their default values. Otherwise, the length should specify the size the - series of control messages consumes. - <p class="Pp">Instead of using <a class="Xr">sendmsg(2)</a> to specify - option values, the ancillary data used in these calls that correspond to - the desired header options may be directly specified as the control - message in the series of control messages provided as the argument to - <a class="Xr">setsockopt(2)</a>.</p> - </dd> - <dt id="IPV6_CHECKSUM"><a class="permalink" href="#IPV6_CHECKSUM"><code class="Dv">IPV6_CHECKSUM</code></a> - <var class="Fa">int *</var></dt> - <dd>Get or set the byte offset into a packet where the 16-bit checksum is - located. When set, this byte offset is where incoming packets will be - expected to have checksums of their data stored and where outgoing packets - will have checksums of their data computed and stored by the kernel. A - value of -1 specifies that no checksums will be checked on incoming - packets and that no checksums will be computed or stored on outgoing - packets. The offset of the checksum for ICMPv6 sockets cannot be relocated - or turned off.</dd> - <dt id="IPV6_V6ONLY"><a class="permalink" href="#IPV6_V6ONLY"><code class="Dv">IPV6_V6ONLY</code></a> - <var class="Fa">int *</var></dt> - <dd>Get or set whether only IPv6 connections can be made to this socket. For - wildcard sockets, this can restrict connections to IPv6 only.</dd> - <dt id="IPV6_FAITH"><a class="permalink" href="#IPV6_FAITH"><code class="Dv">IPV6_FAITH</code></a> - <var class="Fa">int *</var></dt> - <dd>Get or set the status of whether <a class="Xr">faith(4)</a> connections - can be made to this socket.</dd> - <dt id="IPV6_USE_MIN_MTU"><a class="permalink" href="#IPV6_USE_MIN_MTU"><code class="Dv">IPV6_USE_MIN_MTU</code></a> - <var class="Fa">int *</var></dt> - <dd>Get or set whether the minimal IPv6 maximum transmission unit (MTU) size - will be used to avoid fragmentation from occurring for subsequent outgoing - datagrams.</dd> - <dt id="IPV6_AUTH_LEVEL"><a class="permalink" href="#IPV6_AUTH_LEVEL"><code class="Dv">IPV6_AUTH_LEVEL</code></a> - <var class="Fa">int *</var></dt> - <dd>Get or set the <a class="Xr">ipsec(4)</a> authentication level.</dd> - <dt id="IPV6_ESP_TRANS_LEVEL"><a class="permalink" href="#IPV6_ESP_TRANS_LEVEL"><code class="Dv">IPV6_ESP_TRANS_LEVEL</code></a> - <var class="Fa">int *</var></dt> - <dd>Get or set the ESP transport level.</dd> - <dt id="IPV6_ESP_NETWORK_LEVEL"><a class="permalink" href="#IPV6_ESP_NETWORK_LEVEL"><code class="Dv">IPV6_ESP_NETWORK_LEVEL</code></a> - <var class="Fa">int *</var></dt> - <dd>Get or set the ESP encapsulation level.</dd> - <dt id="IPV6_IPCOMP_LEVEL"><a class="permalink" href="#IPV6_IPCOMP_LEVEL"><code class="Dv">IPV6_IPCOMP_LEVEL</code></a> - <var class="Fa">int *</var></dt> - <dd>Get or set the <a class="Xr">ipcomp(4)</a> level.</dd> - <dt id="IPV6_BINDANY"><a class="permalink" href="#IPV6_BINDANY"><code class="Dv">IPV6_BINDANY</code></a></dt> - <dd>If this option is enabled on a <code class="Dv">SOCK_STREAM</code>, - <code class="Dv">SOCK_DGRAM</code>, or a <code class="Dv">SOCK_RAW</code> - socket, one can <a class="Xr">bind(2)</a> to any address, even one not - bound to any available network interface in the system. This functionality - (in conjunction with special firewall rules) can be used for implementing - a transparent proxy. The - <code class="Dv">KAUTH_REQ_NETWORK_BIND_ANYADDR</code> privilege is needed - to set this option.</dd> -</dl> -<p class="Pp">The <code class="Dv">IPV6_PKTINFO</code>, - <code class="Dv">IPV6_HOPLIMIT</code>, <code class="Dv">IPV6_HOPOPTS</code>, - <code class="Dv">IPV6_DSTOPTS</code>, and <code class="Dv">IPV6_RTHDR</code> - options will return ancillary data along with payload contents in subsequent - <a class="Xr">recvmsg(2)</a> calls with <var class="Va">cmsg_level</var> set - to <code class="Dv">IPPROTO_IPV6</code> and <var class="Va">cmsg_type</var> - set to respective option name value (e.g., - <code class="Dv">IPV6_HOPTLIMIT</code>). These options may also be used - directly as ancillary <var class="Va">cmsg_type</var> values in - <a class="Xr">sendmsg(2)</a> to set options on the packet being transmitted - by the call. The <var class="Va">cmsg_level</var> value must be - <code class="Dv">IPPROTO_IPV6</code>. For these options, the ancillary data - object value format is the same as the value returned as explained for each - when received with <a class="Xr">recvmsg(2)</a>.</p> -<p class="Pp">Note that using <a class="Xr">sendmsg(2)</a> to specify options on - particular packets works only on UDP and raw sockets. To manipulate header - options for packets on TCP sockets, only the socket options may be used.</p> -<p class="Pp">In some cases, there are multiple APIs defined for manipulating an - IPv6 header field. A good example is the outgoing interface for multicast - datagrams, which can be set by the <code class="Dv">IPV6_MULTICAST_IF</code> - socket option, through the <code class="Dv">IPV6_PKTINFO</code> option, and - through the <var class="Va">sin6_scope_id</var> field of the socket address - passed to the <a class="Xr">sendto(2)</a> system call.</p> -<p class="Pp">Resolving these conflicts is implementation dependent. This - implementation determines the value in the following way: options specified - by using ancillary data (i.e., <a class="Xr">sendmsg(2)</a>) are considered - first, options specified by using <code class="Dv">IPV6_PKTOPTIONS</code> to - set “sticky” options are considered second, options specified - by using the individual, basic, and direct socket options (e.g., - <code class="Dv">IPV6_UNICAST_HOPS</code>) are considered third, and options - specified in the socket address supplied to <a class="Xr">sendto(2)</a> are - the last choice.</p> -</section> -<section class="Ss"> -<h2 class="Ss" id="Multicasting"><a class="permalink" href="#Multicasting">Multicasting</a></h2> -<p class="Pp">IPv6 multicasting is supported only on - <code class="Dv">AF_INET6</code> sockets of type - <code class="Dv">SOCK_DGRAM</code> and <code class="Dv">SOCK_RAW</code>, and - only on networks where the interface driver supports multicasting. Socket - options (see above) that manipulate membership of multicast groups and other - multicast options include <code class="Dv">IPV6_MULTICAST_IF</code>, - <code class="Dv">IPV6_MULTICAST_HOPS</code>, - <code class="Dv">IPV6_MULTICAST_LOOP</code>, - <code class="Dv">IPV6_LEAVE_GROUP</code>, and - <code class="Dv">IPV6_JOIN_GROUP</code>.</p> -</section> -<section class="Ss"> -<h2 class="Ss" id="Raw_Sockets"><a class="permalink" href="#Raw_Sockets">Raw - Sockets</a></h2> -<p class="Pp">Raw IPv6 sockets are connectionless and are normally used with the - <a class="Xr">sendto(2)</a> and <a class="Xr">recvfrom(2)</a> calls, - although the <a class="Xr">connect(2)</a> call may be used to fix the - destination address for future outgoing packets so that - <a class="Xr">send(2)</a> may instead be used and the - <a class="Xr">bind(2)</a> call may be used to fix the source address for - future outgoing packets instead of having the kernel choose a source - address.</p> -<p class="Pp">By using <a class="Xr">connect(2)</a> or - <a class="Xr">bind(2)</a>, raw socket input is constrained to only packets - with their source address matching the socket destination address if - <a class="Xr">connect(2)</a> was used and to packets with their destination - address matching the socket source address if <a class="Xr">bind(2)</a> was - used.</p> -<p class="Pp" id="not">If the <var class="Ar">proto</var> argument to - <a class="Xr">socket(2)</a> is zero, the default protocol - (<code class="Dv">IPPROTO_RAW</code>) is used for outgoing packets. For - incoming packets, protocols recognized by kernel are - <a class="permalink" href="#not"><b class="Sy">not</b></a> passed to the - application socket (e.g., <a class="Xr">tcp(4)</a> and - <a class="Xr">udp(4)</a>) except for some ICMPv6 messages. The ICMPv6 - messages not passed to raw sockets include echo, timestamp, and address mask - requests. If <var class="Ar">proto</var> is non-zero, only packets with this - protocol will be passed to the socket.</p> -<p class="Pp">IPv6 fragments are also not passed to application sockets until - they have been reassembled. If reception of all packets is desired, - link-level access (such as <a class="Xr">bpf(4)</a>) must be used - instead.</p> -<p class="Pp">Outgoing packets automatically have an IPv6 header prepended to - them (based on the destination address and the protocol number the socket - was created with). Incoming packets are received by an application without - the IPv6 header or any extension headers.</p> -<p class="Pp">Outgoing packets will be fragmented automatically by the kernel if - they are too large. Incoming packets will be reassembled before being sent - to the raw socket, so packet fragments or fragment headers will never be - seen on a raw socket.</p> -</section> -</section> -<section class="Sh"> -<h1 class="Sh" id="EXAMPLES"><a class="permalink" href="#EXAMPLES">EXAMPLES</a></h1> -<p class="Pp">The following determines the hop limit on the next packet - received:</p> -<div class="Bd Pp Li"> -<pre>struct iovec iov[2]; -u_char buf[BUFSIZ]; -struct cmsghdr *cm; -struct msghdr m; -int found, optval; -u_char data[2048]; - -/* Create socket. */ - -(void)memset(&m, 0, sizeof(m)); -(void)memset(&iov, 0, sizeof(iov)); - -iov[0].iov_base = data; /* buffer for packet payload */ -iov[0].iov_len = sizeof(data); /* expected packet length */ - -m.msg_name = &from; /* sockaddr_in6 of peer */ -m.msg_namelen = sizeof(from); -m.msg_iov = iov; -m.msg_iovlen = 1; -m.msg_control = buf; /* buffer for control messages */ -m.msg_controllen = sizeof(buf); - -/* - * Enable the hop limit value from received packets to be - * returned along with the payload. - */ -optval = 1; -if (setsockopt(s, IPPROTO_IPV6, IPV6_HOPLIMIT, &optval, - sizeof(optval)) == -1) - err(1, "setsockopt"); - -found = 0; -while (!found) { - if (recvmsg(s, &m, 0) == -1) - err(1, "recvmsg"); - for (cm = CMSG_FIRSTHDR(&m); cm != NULL; - cm = CMSG_NXTHDR(&m, cm)) { - if (cm->cmsg_level == IPPROTO_IPV6 && - cm->cmsg_type == IPV6_HOPLIMIT && - cm->cmsg_len == CMSG_LEN(sizeof(int))) { - found = 1; - (void)printf("hop limit: %d\n", - *(int *)CMSG_DATA(cm)); - break; - } - } -}</pre> -</div> -</section> -<section class="Sh"> -<h1 class="Sh" id="DIAGNOSTICS"><a class="permalink" href="#DIAGNOSTICS">DIAGNOSTICS</a></h1> -<p class="Pp">A socket operation may fail with one of the following errors - returned:</p> -<dl class="Bl-tag"> - <dt>[<code class="Er">EISCONN</code>]</dt> - <dd>when trying to establish a connection on a socket which already has one or - when trying to send a datagram with the destination address specified and - the socket is already connected.</dd> - <dt>[<code class="Er">ENOTCONN</code>]</dt> - <dd>when trying to send a datagram, but no destination address is specified, - and the socket hasn't been connected.</dd> - <dt>[<code class="Er">ENOBUFS</code>]</dt> - <dd>when the system runs out of memory for an internal data structure.</dd> - <dt>[<code class="Er">EADDRNOTAVAIL</code>]</dt> - <dd>when an attempt is made to create a socket with a network address for - which no network interface exists.</dd> - <dt>[<code class="Er">EACCES</code>]</dt> - <dd>when an attempt is made to create a raw IPv6 socket by a non-privileged - process.</dd> -</dl> -<p class="Pp">The following errors specific to IPv6 may occur when setting or - getting header options:</p> -<dl class="Bl-tag"> - <dt>[<code class="Er">EINVAL</code>]</dt> - <dd>An unknown socket option name was given.</dd> - <dt>[<code class="Er">EINVAL</code>]</dt> - <dd>An ancillary data object was improperly formed.</dd> -</dl> -</section> -<section class="Sh"> -<h1 class="Sh" id="SEE_ALSO"><a class="permalink" href="#SEE_ALSO">SEE - ALSO</a></h1> -<p class="Pp"><a class="Xr">getsockopt(2)</a>, <a class="Xr">recv(2)</a>, - <a class="Xr">send(2)</a>, <a class="Xr">setsockopt(2)</a>, - <a class="Xr">socket(2)</a>, <a class="Xr">CMSG_DATA(3)</a>, - <a class="Xr">if_nametoindex(3)</a>, <a class="Xr">bpf(4)</a>, - <a class="Xr">icmp6(4)</a>, <a class="Xr">inet6(4)</a>, - <a class="Xr">netintro(4)</a>, <a class="Xr">tcp(4)</a>, - <a class="Xr">udp(4)</a></p> -<p class="Pp"><cite class="Rs"><span class="RsA">W. Stevens</span> and - <span class="RsA">M. Thomas</span>, <span class="RsT">Advanced Sockets API - for IPv6</span>, <span class="RsR">RFC 2292</span>, - <span class="RsD">February 1998</span>.</cite></p> -<p class="Pp"><cite class="Rs"><span class="RsA">S. Deering</span> and - <span class="RsA">R. Hinden</span>, <span class="RsT">Internet Protocol, - Version 6 (IPv6) Specification</span>, <span class="RsR">RFC 2460</span>, - <span class="RsD">December 1998</span>.</cite></p> -<p class="Pp"><cite class="Rs"><span class="RsA">R. Gilligan</span>, - <span class="RsA">S. Thomson</span>, <span class="RsA">J. Bound</span>, and - <span class="RsA">W. Stevens</span>, <span class="RsT">Basic Socket - Interface Extensions for IPv6</span>, <span class="RsR">RFC 2553</span>, - <span class="RsD">March 1999</span>.</cite></p> -<p class="Pp"><cite class="Rs"><span class="RsA">W. Stevens</span>, - <span class="RsA">B. Fenner</span>, and <span class="RsA">A. Rudoff</span>, - <span class="RsT">UNIX Network Programming, third edition</span>.</cite></p> -</section> -<section class="Sh"> -<h1 class="Sh" id="STANDARDS"><a class="permalink" href="#STANDARDS">STANDARDS</a></h1> -<p class="Pp">Most of the socket options are defined in RFC 2292 or RFC 2553. - The <code class="Dv">IPV6_V6ONLY</code> socket option is defined in RFC - 3542. The <code class="Dv">IPV6_PORTRANGE</code> socket option and the - conflict resolution rule are not defined in the RFCs and should be - considered implementation dependent.</p> -</section> -</div> -<table class="foot"> - <tr> - <td class="foot-date">September 4, 2024</td> - <td class="foot-os">NetBSD 10.1</td> - </tr> -</table> |