lokinet/llarp/net/net.cpp
Thomas Winget 7caa87862e standardize include format and pragma once
All #ifndef guards on headers have been removed, I think,
in favor of #pragma once

Headers are now included as `#include "filename"` if the included file
resides in the same directory as the file including it, or any
subdirectory therein.  Otherwise they are included as
`#include <project/top/dir/relative/path/filename>`

The above does not include system/os headers.
2021-03-09 19:01:41 -05:00

678 lines
17 KiB
C++

#include "net.hpp"
#include "net_if.hpp"
#include <stdexcept>
#ifdef ANDROID
#include <llarp/android/ifaddrs.h>
#endif
#ifndef _WIN32
#include <arpa/inet.h>
#ifndef ANDROID
#include <ifaddrs.h>
#endif
#endif
#include "ip.hpp"
#include "ip_range.hpp"
#include <llarp/util/logging/logger.hpp>
#include <llarp/util/str.hpp>
#ifdef ANDROID
#include <llarp/android/ifaddrs.h>
#else
#ifndef _WIN32
#include <ifaddrs.h>
#endif
#endif
#include <cstdio>
#include <list>
bool
operator==(const sockaddr& a, const sockaddr& b)
{
if (a.sa_family != b.sa_family)
return false;
switch (a.sa_family)
{
case AF_INET:
return *((const sockaddr_in*)&a) == *((const sockaddr_in*)&b);
case AF_INET6:
return *((const sockaddr_in6*)&a) == *((const sockaddr_in6*)&b);
default:
return false;
}
}
bool
operator<(const sockaddr_in6& a, const sockaddr_in6& b)
{
return a.sin6_addr < b.sin6_addr || a.sin6_port < b.sin6_port;
}
bool
operator<(const in6_addr& a, const in6_addr& b)
{
return memcmp(&a, &b, sizeof(in6_addr)) < 0;
}
bool
operator==(const in6_addr& a, const in6_addr& b)
{
return memcmp(&a, &b, sizeof(in6_addr)) == 0;
}
bool
operator==(const sockaddr_in& a, const sockaddr_in& b)
{
return a.sin_port == b.sin_port && a.sin_addr.s_addr == b.sin_addr.s_addr;
}
bool
operator==(const sockaddr_in6& a, const sockaddr_in6& b)
{
return a.sin6_port == b.sin6_port && a.sin6_addr == b.sin6_addr;
}
#ifdef _WIN32
#include <assert.h>
#include <errno.h>
#include <iphlpapi.h>
#include <strsafe.h>
// current strategy: mingw 32-bit builds call an inlined version of the function
// microsoft c++ and mingw 64-bit builds call the normal function
#define DEFAULT_BUFFER_SIZE 15000
// in any case, we still need to implement some form of
// getifaddrs(3) with compatible semantics on NT...
// daemon.ini section [bind] will have something like
// [bind]
// Ethernet=1090
// inside, since that's what we use in windows to refer to
// network interfaces
struct llarp_nt_ifaddrs_t
{
struct llarp_nt_ifaddrs_t* ifa_next; /* Pointer to the next structure. */
char* ifa_name; /* Name of this network interface. */
unsigned int ifa_flags; /* Flags as from SIOCGIFFLAGS ioctl. */
struct sockaddr* ifa_addr; /* Network address of this interface. */
struct sockaddr* ifa_netmask; /* Netmask of this interface. */
};
// internal struct
struct _llarp_nt_ifaddrs_t
{
struct llarp_nt_ifaddrs_t _ifa;
char _name[256];
struct sockaddr_storage _addr;
struct sockaddr_storage _netmask;
};
static inline void*
_llarp_nt_heap_alloc(const size_t n_bytes)
{
/* Does not appear very safe with re-entrant calls on XP */
return HeapAlloc(GetProcessHeap(), HEAP_GENERATE_EXCEPTIONS, n_bytes);
}
static inline void
_llarp_nt_heap_free(void* mem)
{
HeapFree(GetProcessHeap(), 0, mem);
}
#define llarp_nt_new0(struct_type, n_structs) \
((struct_type*)malloc((size_t)sizeof(struct_type) * (size_t)(n_structs)))
int
llarp_nt_sockaddr_pton(const char* src, struct sockaddr* dst)
{
struct addrinfo hints;
struct addrinfo* result = nullptr;
memset(&hints, 0, sizeof(struct addrinfo));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_DGRAM;
hints.ai_protocol = IPPROTO_TCP;
hints.ai_flags = AI_NUMERICHOST;
const int status = getaddrinfo(src, nullptr, &hints, &result);
if (!status)
{
memcpy(dst, result->ai_addr, result->ai_addrlen);
freeaddrinfo(result);
return 1;
}
return 0;
}
/* NB: IP_ADAPTER_INFO size varies size due to sizeof (time_t), the API assumes
* 4-byte datatype whilst compiler uses an 8-byte datatype. Size can be forced
* with -D_USE_32BIT_TIME_T with side effects to everything else.
*
* Only supports IPv4 addressing similar to SIOCGIFCONF socket option.
*
* Interfaces that are not "operationally up" will return the address 0.0.0.0,
* this includes adapters with static IP addresses but with disconnected cable.
* This is documented under the GetIpAddrTable API. Interface status can only
* be determined by the address, a separate flag is introduced with the
* GetAdapterAddresses API.
*
* The IPv4 loopback interface is not included.
*
* Available in Windows 2000 and Wine 1.0.
*/
static bool
_llarp_nt_getadaptersinfo(struct llarp_nt_ifaddrs_t** ifap)
{
DWORD dwRet;
ULONG ulOutBufLen = DEFAULT_BUFFER_SIZE;
PIP_ADAPTER_INFO pAdapterInfo = nullptr;
PIP_ADAPTER_INFO pAdapter = nullptr;
/* loop to handle interfaces coming online causing a buffer overflow
* between first call to list buffer length and second call to enumerate.
*/
for (unsigned i = 3; i; i--)
{
#ifdef DEBUG
fprintf(stderr, "IP_ADAPTER_INFO buffer length %lu bytes.\n", ulOutBufLen);
#endif
pAdapterInfo = (IP_ADAPTER_INFO*)_llarp_nt_heap_alloc(ulOutBufLen);
dwRet = GetAdaptersInfo(pAdapterInfo, &ulOutBufLen);
if (ERROR_BUFFER_OVERFLOW == dwRet)
{
_llarp_nt_heap_free(pAdapterInfo);
pAdapterInfo = nullptr;
}
else
{
break;
}
}
switch (dwRet)
{
case ERROR_SUCCESS: /* NO_ERROR */
break;
case ERROR_BUFFER_OVERFLOW:
errno = ENOBUFS;
if (pAdapterInfo)
_llarp_nt_heap_free(pAdapterInfo);
return false;
default:
errno = dwRet;
#ifdef DEBUG
fprintf(stderr, "system call failed: %lu\n", GetLastError());
#endif
if (pAdapterInfo)
_llarp_nt_heap_free(pAdapterInfo);
return false;
}
/* count valid adapters */
int n = 0, k = 0;
for (pAdapter = pAdapterInfo; pAdapter; pAdapter = pAdapter->Next)
{
for (IP_ADDR_STRING* pIPAddr = &pAdapter->IpAddressList; pIPAddr; pIPAddr = pIPAddr->Next)
{
/* skip null adapters */
if (strlen(pIPAddr->IpAddress.String) == 0)
continue;
++n;
}
}
#ifdef DEBUG
fprintf(stderr, "GetAdaptersInfo() discovered %d interfaces.\n", n);
#endif
/* contiguous block for adapter list */
struct _llarp_nt_ifaddrs_t* ifa = llarp_nt_new0(struct _llarp_nt_ifaddrs_t, n);
struct _llarp_nt_ifaddrs_t* ift = ifa;
int val = 0;
/* now populate list */
for (pAdapter = pAdapterInfo; pAdapter; pAdapter = pAdapter->Next)
{
for (IP_ADDR_STRING* pIPAddr = &pAdapter->IpAddressList; pIPAddr; pIPAddr = pIPAddr->Next)
{
/* skip null adapters */
if (strlen(pIPAddr->IpAddress.String) == 0)
continue;
/* address */
ift->_ifa.ifa_addr = (struct sockaddr*)&ift->_addr;
val = llarp_nt_sockaddr_pton(pIPAddr->IpAddress.String, ift->_ifa.ifa_addr);
assert(1 == val);
/* name */
#ifdef DEBUG
fprintf(stderr, "name:%s IPv4 index:%lu\n", pAdapter->AdapterName, pAdapter->Index);
#endif
ift->_ifa.ifa_name = ift->_name;
StringCchCopyN(ift->_ifa.ifa_name, 128, pAdapter->AdapterName, 128);
/* flags: assume up, broadcast and multicast */
ift->_ifa.ifa_flags = IFF_UP | IFF_BROADCAST | IFF_MULTICAST;
if (pAdapter->Type == MIB_IF_TYPE_LOOPBACK)
ift->_ifa.ifa_flags |= IFF_LOOPBACK;
/* netmask */
ift->_ifa.ifa_netmask = (sockaddr*)&ift->_netmask;
val = llarp_nt_sockaddr_pton(pIPAddr->IpMask.String, ift->_ifa.ifa_netmask);
assert(1 == val);
/* next */
if (k++ < (n - 1))
{
ift->_ifa.ifa_next = (struct llarp_nt_ifaddrs_t*)(ift + 1);
ift = (struct _llarp_nt_ifaddrs_t*)(ift->_ifa.ifa_next);
}
else
{
ift->_ifa.ifa_next = nullptr;
}
}
}
if (pAdapterInfo)
_llarp_nt_heap_free(pAdapterInfo);
*ifap = (struct llarp_nt_ifaddrs_t*)ifa;
return true;
}
// an implementation of if_nametoindex(3) based on GetAdapterIndex(2)
// with a fallback to GetAdaptersAddresses(2) commented out for now
// unless it becomes evident that the first codepath fails in certain
// edge cases?
static unsigned
_llarp_nt_nametoindex(const char* ifname)
{
ULONG ifIndex;
DWORD dwRet;
char szAdapterName[256];
if (!ifname)
return 0;
StringCchCopyN(szAdapterName, sizeof(szAdapterName), ifname, 256);
dwRet = GetAdapterIndex((LPWSTR)szAdapterName, &ifIndex);
if (!dwRet)
return ifIndex;
else
return 0;
}
// the emulated getifaddrs(3) itself.
static bool
llarp_nt_getifaddrs(struct llarp_nt_ifaddrs_t** ifap)
{
assert(nullptr != ifap);
#ifdef DEBUG
fprintf(stderr, "llarp_nt_getifaddrs (ifap:%p error:%p)\n", (void*)ifap, (void*)errno);
#endif
return _llarp_nt_getadaptersinfo(ifap);
}
static void
llarp_nt_freeifaddrs(struct llarp_nt_ifaddrs_t* ifa)
{
if (!ifa)
return;
free(ifa);
}
// emulated if_nametoindex(3)
static unsigned
llarp_nt_if_nametoindex(const char* ifname)
{
if (!ifname)
return 0;
return _llarp_nt_nametoindex(ifname);
}
// fix up names for win32
#define ifaddrs llarp_nt_ifaddrs_t
#define getifaddrs llarp_nt_getifaddrs
#define freeifaddrs llarp_nt_freeifaddrs
#define if_nametoindex llarp_nt_if_nametoindex
#endif
// jeff's original code
bool
llarp_getifaddr(const char* ifname, int af, struct sockaddr* addr)
{
ifaddrs* ifa = nullptr;
bool found = false;
socklen_t sl = sizeof(sockaddr_in6);
if (af == AF_INET)
sl = sizeof(sockaddr_in);
#ifndef _WIN32
if (getifaddrs(&ifa) == -1)
#else
if (!strcmp(ifname, "lo") || !strcmp(ifname, "lo0"))
{
if (addr)
{
sockaddr_in* lo = (sockaddr_in*)addr;
lo->sin_family = af;
lo->sin_port = 0;
inet_pton(af, "127.0.0.1", &lo->sin_addr);
}
return true;
}
if (!getifaddrs(&ifa))
#endif
return false;
ifaddrs* i = ifa;
while (i)
{
if (i->ifa_addr)
{
// llarp::LogInfo(__FILE__, "scanning ", i->ifa_name, " af: ",
// std::to_string(i->ifa_addr->sa_family));
if (std::string_view{i->ifa_name} == std::string_view{ifname} && i->ifa_addr->sa_family == af)
{
// can't do this here
// llarp::Addr a(*i->ifa_addr);
// if(!a.isPrivate())
//{
// llarp::LogInfo(__FILE__, "found ", ifname, " af: ", af);
if (addr)
{
memcpy(addr, i->ifa_addr, sl);
if (af == AF_INET6)
{
// set scope id
auto* ip6addr = (sockaddr_in6*)addr;
ip6addr->sin6_scope_id = if_nametoindex(ifname);
ip6addr->sin6_flowinfo = 0;
}
}
found = true;
break;
}
//}
}
i = i->ifa_next;
}
if (ifa)
freeifaddrs(ifa);
return found;
}
namespace llarp
{
static void
IterAllNetworkInterfaces(std::function<void(ifaddrs* const)> visit)
{
ifaddrs* ifa = nullptr;
#ifndef _WIN32
if (getifaddrs(&ifa) == -1)
#else
if (!getifaddrs(&ifa))
#endif
return;
ifaddrs* i = ifa;
while (i)
{
visit(i);
i = i->ifa_next;
}
if (ifa)
freeifaddrs(ifa);
}
namespace net
{
std::string
LoopbackInterfaceName()
{
const auto loopback = IPRange::FromIPv4(127, 0, 0, 0, 8);
std::string ifname;
IterAllNetworkInterfaces([&ifname, loopback](ifaddrs* const i) {
if (i->ifa_addr and i->ifa_addr->sa_family == AF_INET)
{
llarp::nuint32_t addr{((sockaddr_in*)i->ifa_addr)->sin_addr.s_addr};
if (loopback.Contains(xntohl(addr)))
{
ifname = i->ifa_name;
}
}
});
if (ifname.empty())
{
throw std::runtime_error(
"we have no ipv4 loopback interface for some ungodly reason, yeah idk fam");
}
return ifname;
}
} // namespace net
bool
GetBestNetIF(std::string& ifname, int af)
{
bool found = false;
IterAllNetworkInterfaces([&](ifaddrs* i) {
if (found)
return;
if (i->ifa_addr)
{
if (i->ifa_addr->sa_family == af)
{
llarp::SockAddr a(*i->ifa_addr);
llarp::IpAddress ip(a);
if (!ip.isBogon())
{
ifname = i->ifa_name;
found = true;
}
}
}
});
return found;
}
// TODO: ipv6?
std::optional<IPRange>
FindFreeRange()
{
std::list<IPRange> currentRanges;
IterAllNetworkInterfaces([&](ifaddrs* i) {
if (i && i->ifa_addr)
{
const auto fam = i->ifa_addr->sa_family;
if (fam != AF_INET)
return;
auto* addr = (sockaddr_in*)i->ifa_addr;
auto* mask = (sockaddr_in*)i->ifa_netmask;
nuint32_t ifaddr{addr->sin_addr.s_addr};
nuint32_t ifmask{mask->sin_addr.s_addr};
#ifdef _WIN32
// do not delete, otherwise GCC will do horrible things to this lambda
LogDebug("found ", ifaddr, " with mask ", ifmask);
#endif
if (addr->sin_addr.s_addr)
// skip unconfig'd adapters (windows passes these through the unix-y
// wrapper)
currentRanges.emplace_back(
IPRange{net::ExpandV4(xntohl(ifaddr)), net::ExpandV4(xntohl(ifmask))});
}
});
auto ownsRange = [&currentRanges](IPRange range) -> bool {
for (const auto& ownRange : currentRanges)
{
if (ownRange.Contains(range))
return true;
}
return false;
};
// generate possible ranges to in order of attempts
std::list<IPRange> possibleRanges;
for (byte_t oct = 16; oct < 32; ++oct)
{
possibleRanges.emplace_back(IPRange::FromIPv4(172, oct, 0, 1, 16));
}
for (byte_t oct = 0; oct < 255; ++oct)
{
possibleRanges.emplace_back(IPRange::FromIPv4(10, oct, 0, 1, 16));
}
for (byte_t oct = 0; oct < 255; ++oct)
{
possibleRanges.emplace_back(IPRange::FromIPv4(192, 168, oct, 1, 24));
}
// for each possible range pick the first one we don't own
for (const auto& range : possibleRanges)
{
if (not ownsRange(range))
return range;
}
return std::nullopt;
}
std::optional<std::string>
FindFreeTun()
{
int num = 0;
while (num < 255)
{
std::stringstream ifname_ss;
ifname_ss << "lokitun" << num;
std::string iftestname = ifname_ss.str();
bool found = llarp_getifaddr(iftestname.c_str(), AF_INET, nullptr);
if (!found)
{
return iftestname;
}
num++;
}
return std::nullopt;
}
std::optional<SockAddr>
GetInterfaceAddr(const std::string& ifname, int af)
{
sockaddr_storage s;
sockaddr* sptr = (sockaddr*)&s;
sptr->sa_family = af;
if (!llarp_getifaddr(ifname.c_str(), af, sptr))
return std::nullopt;
return SockAddr{*sptr};
}
std::optional<huint128_t>
GetInterfaceIPv6Address(std::string ifname)
{
sockaddr_storage s;
sockaddr* sptr = (sockaddr*)&s;
sptr->sa_family = AF_INET6;
if (!llarp_getifaddr(ifname.c_str(), AF_INET6, sptr))
return std::nullopt;
llarp::SockAddr addr{*sptr};
return addr.asIPv6();
}
bool
AllInterfaces(int af, SockAddr& result)
{
if (af == AF_INET)
{
sockaddr_in addr;
addr.sin_family = AF_INET;
addr.sin_addr.s_addr = htonl(INADDR_ANY);
addr.sin_port = htons(0);
result = SockAddr{addr};
return true;
}
if (af == AF_INET6)
{
sockaddr_in6 addr6;
addr6.sin6_family = AF_INET6;
addr6.sin6_port = htons(0);
addr6.sin6_addr = IN6ADDR_ANY_INIT;
result = SockAddr{addr6};
return true;
}
return false;
}
bool
IsBogon(const in6_addr& addr)
{
#if defined(TESTNET)
(void)addr;
return false;
#else
if (!ipv6_is_mapped_ipv4(addr))
{
static in6_addr zero = {};
if (addr == zero)
return true;
return false;
}
return IsIPv4Bogon(
ipaddr_ipv4_bits(addr.s6_addr[12], addr.s6_addr[13], addr.s6_addr[14], addr.s6_addr[15]));
#endif
}
bool
IsBogon(const huint128_t ip)
{
const nuint128_t netIP{ntoh128(ip.h)};
in6_addr addr{};
std::copy_n((const uint8_t*)&netIP.n, 16, &addr.s6_addr[0]);
return IsBogon(addr);
}
bool
IsBogonRange(const in6_addr& host, const in6_addr&)
{
// TODO: implement me
return IsBogon(host);
}
#if !defined(TESTNET)
static constexpr std::array bogonRanges = {
IPRange::FromIPv4(0, 0, 0, 0, 8),
IPRange::FromIPv4(10, 0, 0, 0, 8),
IPRange::FromIPv4(21, 0, 0, 0, 8),
IPRange::FromIPv4(100, 64, 0, 0, 10),
IPRange::FromIPv4(127, 0, 0, 0, 8),
IPRange::FromIPv4(169, 254, 0, 0, 16),
IPRange::FromIPv4(172, 16, 0, 0, 12),
IPRange::FromIPv4(192, 0, 0, 0, 24),
IPRange::FromIPv4(192, 0, 2, 0, 24),
IPRange::FromIPv4(192, 88, 99, 0, 24),
IPRange::FromIPv4(192, 168, 0, 0, 16),
IPRange::FromIPv4(198, 18, 0, 0, 15),
IPRange::FromIPv4(198, 51, 100, 0, 24),
IPRange::FromIPv4(203, 0, 113, 0, 24),
IPRange::FromIPv4(224, 0, 0, 0, 4),
IPRange::FromIPv4(240, 0, 0, 0, 4)};
bool
IsIPv4Bogon(const huint32_t& addr)
{
for (const auto& bogon : bogonRanges)
{
if (bogon.Contains(addr))
{
return true;
}
}
return false;
}
#else
bool
IsIPv4Bogon(const huint32_t&)
{
return false;
}
#endif
} // namespace llarp