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Diffstat (limited to 'man3/getifaddrs.3')
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diff --git a/man3/getifaddrs.3 b/man3/getifaddrs.3 deleted file mode 100644 index 3ecaf71c0..000000000 --- a/man3/getifaddrs.3 +++ /dev/null @@ -1,313 +0,0 @@ -'\" t -.\" Copyright (c) 2008 Petr Baudis <pasky@suse.cz> -.\" and copyright (c) 2009, Linux Foundation, written by Michael Kerrisk -.\" <mtk.manpages@gmail.com> -.\" -.\" SPDX-License-Identifier: Linux-man-pages-copyleft -.\" -.\" Redistribution and use in source and binary forms, with or without -.\" modification, are permitted provided that the following conditions -.\" are met: -.\" -.\" 2008-12-08 Petr Baudis <pasky@suse.cz> -.\" Rewrite the BSD manpage in the Linux man pages style and account -.\" for glibc specificities, provide an example. -.\" 2009-01-14 mtk, many edits and changes, rewrote example program. -.\" -.TH getifaddrs 3 (date) "Linux man-pages (unreleased)" -.SH NAME -getifaddrs, freeifaddrs \- get interface addresses -.SH LIBRARY -Standard C library -.RI ( libc ", " \-lc ) -.SH SYNOPSIS -.nf -.B #include <sys/types.h> -.B #include <ifaddrs.h> -.P -.BI "int getifaddrs(struct ifaddrs **" "ifap" ); -.BI "void freeifaddrs(struct ifaddrs *" "ifa" ); -.fi -.SH DESCRIPTION -The -.BR getifaddrs () -function creates a linked list of structures describing -the network interfaces of the local system, -and stores the address of the first item of the list in -.IR *ifap . -The list consists of -.I ifaddrs -structures, defined as follows: -.P -.in +4n -.EX -struct ifaddrs { - struct ifaddrs *ifa_next; /* Next item in list */ - char *ifa_name; /* Name of interface */ - unsigned int ifa_flags; /* Flags from SIOCGIFFLAGS */ - struct sockaddr *ifa_addr; /* Address of interface */ - struct sockaddr *ifa_netmask; /* Netmask of interface */ - union { - struct sockaddr *ifu_broadaddr; - /* Broadcast address of interface */ - struct sockaddr *ifu_dstaddr; - /* Point\-to\-point destination address */ - } ifa_ifu; -#define ifa_broadaddr ifa_ifu.ifu_broadaddr -#define ifa_dstaddr ifa_ifu.ifu_dstaddr - void *ifa_data; /* Address\-specific data */ -}; -.EE -.in -.P -The -.I ifa_next -field contains a pointer to the next structure on the list, -or NULL if this is the last item of the list. -.P -The -.I ifa_name -points to the null-terminated interface name. -.\" The constant -.\" .B IF NAMESIZE -.\" indicates the maximum length of this field. -.P -The -.I ifa_flags -field contains the interface flags, as returned by the -.B SIOCGIFFLAGS -.BR ioctl (2) -operation (see -.BR netdevice (7) -for a list of these flags). -.P -The -.I ifa_addr -field points to a structure containing the interface address. -(The -.I sa_family -subfield should be consulted to determine the format of the -address structure.) -This field may contain a null pointer. -.P -The -.I ifa_netmask -field points to a structure containing the netmask associated with -.IR ifa_addr , -if applicable for the address family. -This field may contain a null pointer. -.P -Depending on whether the bit -.B IFF_BROADCAST -or -.B IFF_POINTOPOINT -is set in -.I ifa_flags -(only one can be set at a time), -either -.I ifa_broadaddr -will contain the broadcast address associated with -.I ifa_addr -(if applicable for the address family) or -.I ifa_dstaddr -will contain the destination address of the point-to-point interface. -.P -The -.I ifa_data -field points to a buffer containing address-family-specific data; -this field may be NULL if there is no such data for this interface. -.P -The data returned by -.BR getifaddrs () -is dynamically allocated and should be freed using -.BR freeifaddrs () -when no longer needed. -.SH RETURN VALUE -On success, -.BR getifaddrs () -returns zero; -on error, \-1 is returned, and -.I errno -is set to indicate the error. -.SH ERRORS -.BR getifaddrs () -may fail and set -.I errno -for any of the errors specified for -.BR socket (2), -.BR bind (2), -.BR getsockname (2), -.BR recvmsg (2), -.BR sendto (2), -.BR malloc (3), -or -.BR realloc (3). -.SH ATTRIBUTES -For an explanation of the terms used in this section, see -.BR attributes (7). -.TS -allbox; -lbx lb lb -l l l. -Interface Attribute Value -T{ -.na -.nh -.BR getifaddrs (), -.BR freeifaddrs () -T} Thread safety MT-Safe -.TE -.SH STANDARDS -None. -.SH HISTORY -This function first appeared in BSDi and is -present on the BSD systems, but with slightly different -semantics documented\[em]returning one entry per interface, -not per address. -This means -.I ifa_addr -and other fields can actually be NULL if the interface has no address, -and no link-level address is returned if the interface has an IP address -assigned. -Also, the way of choosing either -.I ifa_broadaddr -or -.I ifa_dstaddr -differs on various systems. -.\" , but the BSD-derived documentation generally -.\" appears to be confused and obsolete on this point. -.\" i.e., commonly it still says one of them will be NULL, even if -.\" the ifa_ifu union is already present -.P -.BR getifaddrs () -first appeared in glibc 2.3, but before glibc 2.3.3, -the implementation supported only IPv4 addresses; -IPv6 support was added in glibc 2.3.3. -Support of address families other than IPv4 is available only -on kernels that support netlink. -.SH NOTES -The addresses returned on Linux will usually be the IPv4 and IPv6 addresses -assigned to the interface, but also one -.B AF_PACKET -address per interface containing lower-level details about the interface -and its physical layer. -In this case, the -.I ifa_data -field may contain a pointer to a -.IR "struct rtnl_link_stats" , -defined in -.I <linux/if_link.h> -(in Linux 2.4 and earlier, -.IR "struct net_device_stats" , -defined in -.IR <linux/netdevice.h> ), -which contains various interface attributes and statistics. -.SH EXAMPLES -The program below demonstrates the use of -.BR getifaddrs (), -.BR freeifaddrs (), -and -.BR getnameinfo (3). -Here is what we see when running this program on one system: -.P -.in +4n -.EX -$ \fB./a.out\fP -lo AF_PACKET (17) - tx_packets = 524; rx_packets = 524 - tx_bytes = 38788; rx_bytes = 38788 -wlp3s0 AF_PACKET (17) - tx_packets = 108391; rx_packets = 130245 - tx_bytes = 30420659; rx_bytes = 94230014 -em1 AF_PACKET (17) - tx_packets = 0; rx_packets = 0 - tx_bytes = 0; rx_bytes = 0 -lo AF_INET (2) - address: <127.0.0.1> -wlp3s0 AF_INET (2) - address: <192.168.235.137> -lo AF_INET6 (10) - address: <::1> -wlp3s0 AF_INET6 (10) - address: <fe80::7ee9:d3ff:fef5:1a91%wlp3s0> -.EE -.in -.SS Program source -\& -.EX -#define _GNU_SOURCE /* To get defns of NI_MAXSERV and NI_MAXHOST */ -#include <arpa/inet.h> -#include <sys/socket.h> -#include <netdb.h> -#include <ifaddrs.h> -#include <stdio.h> -#include <stdlib.h> -#include <unistd.h> -#include <linux/if_link.h> -\& -int main(int argc, char *argv[]) -{ - struct ifaddrs *ifaddr; - int family, s; - char host[NI_MAXHOST]; -\& - if (getifaddrs(&ifaddr) == \-1) { - perror("getifaddrs"); - exit(EXIT_FAILURE); - } -\& - /* Walk through linked list, maintaining head pointer so we - can free list later. */ -\& - for (struct ifaddrs *ifa = ifaddr; ifa != NULL; - ifa = ifa\->ifa_next) { - if (ifa\->ifa_addr == NULL) - continue; -\& - family = ifa\->ifa_addr\->sa_family; -\& - /* Display interface name and family (including symbolic - form of the latter for the common families). */ -\& - printf("%\-8s %s (%d)\en", - ifa\->ifa_name, - (family == AF_PACKET) ? "AF_PACKET" : - (family == AF_INET) ? "AF_INET" : - (family == AF_INET6) ? "AF_INET6" : "???", - family); -\& - /* For an AF_INET* interface address, display the address. */ -\& - if (family == AF_INET || family == AF_INET6) { - s = getnameinfo(ifa\->ifa_addr, - (family == AF_INET) ? sizeof(struct sockaddr_in) : - sizeof(struct sockaddr_in6), - host, NI_MAXHOST, - NULL, 0, NI_NUMERICHOST); - if (s != 0) { - printf("getnameinfo() failed: %s\en", gai_strerror(s)); - exit(EXIT_FAILURE); - } -\& - printf("\et\etaddress: <%s>\en", host); -\& - } else if (family == AF_PACKET && ifa\->ifa_data != NULL) { - struct rtnl_link_stats *stats = ifa\->ifa_data; -\& - printf("\et\ettx_packets = %10u; rx_packets = %10u\en" - "\et\ettx_bytes = %10u; rx_bytes = %10u\en", - stats\->tx_packets, stats\->rx_packets, - stats\->tx_bytes, stats\->rx_bytes); - } - } -\& - freeifaddrs(ifaddr); - exit(EXIT_SUCCESS); -} -.EE -.SH SEE ALSO -.BR bind (2), -.BR getsockname (2), -.BR socket (2), -.BR packet (7), -.BR ifconfig (8) |