cosmopolitan/tool/viz/getifaddrs.c
Justine Tunney 024be3b009
Introduce getifaddrs()
This function was invented by the BSDs (it's not in POSIX.1). It
provides a high-level interface into ioctl(SIOCGIFCONF) which is
comparatively clumsy to use. We already made the ioctls portable
across our entire support vector back in 2021, so this interface
is portable too. See o//tool/viz/getifaddrs.com for our demo app
2023-11-02 08:33:03 -07:00

116 lines
4.4 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2023 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/fmt/itoa.h"
#include "libc/runtime/runtime.h"
#include "libc/sock/ifaddrs.h"
#include "libc/sock/sock.h"
#include "libc/sock/struct/sockaddr.h"
#include "libc/sock/struct/sockaddr6.h"
#include "libc/stdio/stdio.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/af.h"
#include "libc/sysv/consts/iff.h"
/* example output:
eth0
addr: 10.10.10.237
netmask: 255.255.255.0
broadcast: 255.255.255.0
flags: IFF_UP IFF_BROADCAST IFF_MULTICAST IFF_RUNNING
lo
addr: 127.0.0.1
netmask: 255.0.0.0
flags: IFF_UP IFF_LOOPBACK IFF_RUNNING */
const char *sockaddr2str(const struct sockaddr *sa, char *buf, size_t size) {
if (sa->sa_family == AF_INET) {
return inet_ntop(AF_INET, &(((const struct sockaddr_in *)sa)->sin_addr),
buf, size);
} else if (sa->sa_family == AF_INET6) {
return inet_ntop(AF_INET6, &(((const struct sockaddr_in6 *)sa)->sin6_addr),
buf, size);
} else {
return 0;
}
}
int main(int argc, char *argv[]) {
// get network interface list
struct ifaddrs *ifaddrs;
if (getifaddrs(&ifaddrs)) {
perror("getifaddrs");
exit(1);
}
// print network interface list
for (struct ifaddrs *ifa = ifaddrs; ifa; ifa = ifa->ifa_next) {
tinyprint(1, ifa->ifa_name, "\n", NULL);
char buf[128];
if (sockaddr2str(ifa->ifa_addr, buf, sizeof(buf))) {
tinyprint(1, "addr: ", buf, "\n", NULL);
}
if (sockaddr2str(ifa->ifa_netmask, buf, sizeof(buf))) {
tinyprint(1, "netmask: ", buf, "\n", NULL);
}
if ((ifa->ifa_flags & IFF_BROADCAST) &&
sockaddr2str(ifa->ifa_netmask, buf, sizeof(buf))) {
tinyprint(1, "broadcast: ", buf, "\n", NULL);
} else if ((ifa->ifa_flags & IFF_POINTOPOINT) &&
sockaddr2str(ifa->ifa_dstaddr, buf, sizeof(buf))) {
tinyprint(1, "dstaddr: ", buf, "\n", NULL);
}
tinyprint(1, "flags:", NULL);
if (ifa->ifa_flags & IFF_UP) {
tinyprint(1, " IFF_UP", NULL);
}
if (ifa->ifa_flags & IFF_DEBUG) {
tinyprint(1, " IFF_DEBUG", NULL);
}
if (ifa->ifa_flags & IFF_LOOPBACK) {
tinyprint(1, " IFF_LOOPBACK", NULL);
}
if (ifa->ifa_flags & IFF_MULTICAST) {
tinyprint(1, " IFF_MULTICAST", NULL);
}
if (ifa->ifa_flags & IFF_ALLMULTI) {
tinyprint(1, " IFF_ALLMULTI", NULL);
}
if (ifa->ifa_flags & IFF_NOARP) {
tinyprint(1, " IFF_NOARP", NULL);
}
if (ifa->ifa_flags & IFF_PROMISC) {
tinyprint(1, " IFF_PROMISC", NULL);
}
tinyprint(1, "\n", NULL);
tinyprint(1, "\n", NULL);
}
// perform cleanup
freeifaddrs(ifaddrs);
// report success
exit(0);
}