/*

Copyright (c) 2015 Martin Sustrik

Permission is hereby granted, free of charge, to any person obtaining a copy

of this software and associated documentation files (the "Software"),

to deal in the Software without restriction, including without limitation

the rights to use, copy, modify, merge, publish, distribute, sublicense,

and/or sell copies of the Software, and to permit persons to whom

the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included

in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS

IN THE SOFTWARE.

*/

#if defined __linux__

#define _GNU_SOURCE

#include <netdb.h>

#include <sys/eventfd.h>

#endif

#include <arpa/inet.h>

#include <errno.h>

#include <netinet/in.h>

#include <string.h>

#include <sys/types.h>

#include <sys/socket.h>

#if !defined __sun

#include <ifaddrs.h>

#endif

#include <unistd.h>

#include "ip.h"

#include "libmill.h"

#include "utils.h"

MILL_CT_ASSERT(sizeof(ipaddr) >= sizeof(struct sockaddr_in));

MILL_CT_ASSERT(sizeof(ipaddr) >= sizeof(struct sockaddr_in6));

static ipaddr mill_ipany(int port, int mode)

{

ipaddr addr;

if(mill_slow(port < 0 || port > 0xffff)) {

((struct sockaddr*)&addr)->sa_family = AF_UNSPEC;

errno = EINVAL;

return addr;

}

if (mode == 0 || mode == IPADDR_IPV4 || mode == IPADDR_PREF_IPV4) {

struct sockaddr_in *ipv4 = (struct sockaddr_in*)&addr;

ipv4->sin_family = AF_INET;

ipv4->sin_addr.s_addr = htonl(INADDR_ANY);

ipv4->sin_port = htons((uint16_t)port);

}

else {

struct sockaddr_in6 *ipv6 = (struct sockaddr_in6*)&addr;

ipv6->sin6_family = AF_INET6;

memcpy(&ipv6->sin6_addr, &in6addr_any, sizeof(in6addr_any));

ipv6->sin6_port = htons((uint16_t)port);

}

errno = 0;

return addr;

}

/* Convert literal IPv4 address to a binary one. */

static ipaddr mill_ipv4_literal(const char *addr, int port) {

ipaddr raddr;

struct sockaddr_in *ipv4 = (struct sockaddr_in*)&raddr;

int rc = inet_pton(AF_INET, addr, &ipv4->sin_addr);

mill_assert(rc >= 0);

if(rc == 1) {

ipv4->sin_family = AF_INET;

ipv4->sin_port = htons((uint16_t)port);

errno = 0;

return raddr;

}

ipv4->sin_family = AF_UNSPEC;

errno = EINVAL;

return raddr;

}

/* Convert literal IPv6 address to a binary one. */

static ipaddr mill_ipv6_literal(const char *addr, int port) {

ipaddr raddr;

struct sockaddr_in6 *ipv6 = (struct sockaddr_in6*)&raddr;

int rc = inet_pton(AF_INET6, addr, &ipv6->sin6_addr);

mill_assert(rc >= 0);

if(rc == 1) {

ipv6->sin6_family = AF_INET6;

ipv6->sin6_port = htons((uint16_t)port);

errno = 0;

return raddr;

}

ipv6->sin6_family = AF_UNSPEC;

errno = EINVAL;

return raddr;

}

/* Convert literal IPv4 or IPv6 address to a binary one. */

static ipaddr mill_ipliteral(const char *addr, int port, int mode) {

ipaddr raddr;

struct sockaddr *sa = (struct sockaddr*)&raddr;

if(mill_slow(!addr || port < 0 || port > 0xffff)) {

sa->sa_family = AF_UNSPEC;

errno = EINVAL;

return raddr;

}

switch(mode) {

case IPADDR_IPV4:

return mill_ipv4_literal(addr, port);

case IPADDR_IPV6:

return mill_ipv6_literal(addr, port);

case 0:

case IPADDR_PREF_IPV4:

raddr = mill_ipv4_literal(addr, port);

if(errno == 0)

return raddr;

return mill_ipv6_literal(addr, port);

case IPADDR_PREF_IPV6:

raddr = mill_ipv6_literal(addr, port);

if(errno == 0)

return raddr;

return mill_ipv4_literal(addr, port);

default:

mill_assert(0);

}

}

int mill_ipfamily(ipaddr addr) {

return ((struct sockaddr*)&addr)->sa_family;

}

int mill_iplen(ipaddr addr) {

return mill_ipfamily(addr) == AF_INET ?

sizeof(struct sockaddr_in) : sizeof(struct sockaddr_in6);

}

int mill_ipport(ipaddr addr) {

return ntohs(mill_ipfamily(addr) == AF_INET ?

((struct sockaddr_in*)&addr)->sin_port :

((struct sockaddr_in6*)&addr)->sin6_port);

}

ipaddr iplocal(const char *name, int port, int mode) {

if(!name)

return mill_ipany(port, mode);

ipaddr addr = mill_ipliteral(name, port, mode);

#if defined __sun

return addr;

#else

if(errno == 0)

return addr;

/* Address is not a literal. It must be an interface name then. */

struct ifaddrs *ifaces = NULL;

int rc = getifaddrs (&ifaces);

mill_assert (rc == 0);

mill_assert (ifaces);

/* Find first IPv4 and first IPv6 address. */

struct ifaddrs *ipv4 = NULL;

struct ifaddrs *ipv6 = NULL;

struct ifaddrs *it;

for(it = ifaces; it != NULL; it = it->ifa_next) {

if(!it->ifa_addr)

continue;

if(strcmp(it->ifa_name, name) != 0)

continue;

switch(it->ifa_addr->sa_family) {

case AF_INET:

mill_assert(!ipv4);

ipv4 = it;

break;

case AF_INET6:

mill_assert(!ipv6);

ipv6 = it;

break;

}

if(ipv4 && ipv6)

break;

}

/* Choose the correct address family based on mode. */

switch(mode) {

case IPADDR_IPV4:

ipv6 = NULL;

break;

case IPADDR_IPV6:

ipv4 = NULL;

break;

case 0:

case IPADDR_PREF_IPV4:

if(ipv4)

ipv6 = NULL;

break;

case IPADDR_PREF_IPV6:

if(ipv6)

ipv4 = NULL;

break;

default:

mill_assert(0);

}

if(ipv4) {

struct sockaddr_in *inaddr = (struct sockaddr_in*)&addr;

memcpy(inaddr, ipv4->ifa_addr, sizeof (struct sockaddr_in));

inaddr->sin_port = htons(port);

freeifaddrs(ifaces);

errno = 0;

return addr;

}

if(ipv6) {

struct sockaddr_in6 *inaddr = (struct sockaddr_in6*)&addr;

memcpy(inaddr, ipv6->ifa_addr, sizeof (struct sockaddr_in6));

inaddr->sin6_port = htons(port);

freeifaddrs(ifaces);

errno = 0;

return addr;

}

freeifaddrs(ifaces);

((struct sockaddr*)&addr)->sa_family = AF_UNSPEC;

errno = ENODEV;

return addr;

#endif

}

#if defined __linux__

static void mill_getaddrinfo_a_done(union sigval sval) {

uint64_t i = 1;

ssize_t sz = write(sval.sival_int, &i, sizeof(i));

mill_assert(sz == sizeof(i));

}

#endif

ipaddr ipremote(const char *name, int port, int mode, int64_t deadline) {

ipaddr addr = mill_ipliteral(name, port, mode);

#if !defined __linux__

return addr;

#else

if(errno == 0)

return addr;

/* Let's do asynchronous DNS query here. */

int efd = eventfd(0, 0);

if(mill_slow(efd < 0))

return addr;

struct addrinfo request;

memset(&request, 0, sizeof(request));

request.ai_family = AF_UNSPEC;

request.ai_socktype = SOCK_STREAM;

struct gaicb gcb;

memset(&gcb, 0, sizeof(gcb));

gcb.ar_name = name;

gcb.ar_service = NULL;

gcb.ar_request = &request;

gcb.ar_result = NULL;

struct sigevent sev;

memset(&sev, 0, sizeof(sev));

/* The event will be delivered using a new thread rather than by a signal

running of one of the coroutines' stack and possibly breaking it. */

sev.sigev_notify = SIGEV_THREAD;

sev.sigev_notify_function = mill_getaddrinfo_a_done;

sev.sigev_value.sival_int = efd;

struct gaicb *pgcb = &gcb;

int rc = getaddrinfo_a(GAI_NOWAIT, &pgcb, 1, &sev);

if(mill_slow(rc != 0)) {

if(rc == EAI_AGAIN || rc == EAI_MEMORY) {

close(efd);

errno = ENOMEM;

return addr;

}

mill_assert(0);

}

rc = fdwait(efd, FDW_IN, deadline);

if(rc == 0) {

gai_cancel(&gcb);

rc = fdwait(efd, FDW_IN, -1);

}

mill_assert(rc == FDW_IN);

close(efd);

rc = gai_error(&gcb);

if(rc != 0) {

errno = EINVAL;

return addr;

}

struct addrinfo *ipv4 = NULL;

struct addrinfo *ipv6 = NULL;

struct addrinfo *it = gcb.ar_result;

while(it) {

if(!ipv4 && it->ai_family == AF_INET)

ipv4 = it;

if(!ipv6 && it->ai_family == AF_INET6)

ipv6 = it;

if(ipv4 && ipv6)

break;

it = it->ai_next;

}

switch(mode) {

case IPADDR_IPV4:

ipv6 = NULL;

break;

case IPADDR_IPV6:

ipv4 = NULL;

break;

case 0:

case IPADDR_PREF_IPV4:

if(ipv4)

ipv6 = NULL;

break;

case IPADDR_PREF_IPV6:

if(ipv6)

ipv4 = NULL;

break;

default:

mill_assert(0);

}

if(ipv4) {

struct sockaddr_in *inaddr = (struct sockaddr_in*)&addr;

memcpy(inaddr, ipv4->ai_addr, sizeof (struct sockaddr_in));

inaddr->sin_port = htons(port);

}

if(ipv6) {

struct sockaddr_in6 *inaddr = (struct sockaddr_in6*)&addr;

memcpy(inaddr, ipv6->ai_addr, sizeof (struct sockaddr_in6));

inaddr->sin6_port = htons(port);

}

freeaddrinfo(gcb.ar_result);

errno = 0;

return addr;

#endif

}