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dbeacon_posix.cpp
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dbeacon_posix.cpp
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/*
* Copyright 2005-2010, Hugo Santos <hugo@fivebits.net>
* Distributed under the terms of the MIT License.
*/
#include "dbeacon.h"
#include "msocket.h"
#include "address.h"
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <sys/uio.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/times.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <cstdlib>
#ifndef CMSG_LEN
#define CMSG_LEN(size) (sizeof(struct cmsghdr) + (size))
#endif
#ifndef CMSG_SPACE
#define CMSG_SPACE(size) (sizeof(struct cmsghdr) + (size))
#endif
#if defined(SOLARIS) || defined(__NetBSD__)
#define TTLType uint8_t
#else
#define TTLType int
#endif
int _McastListenNewAPI(int sock, const address &grpaddr);
int _McastListenOldAPI(int sock, const address &grpaddr);
static int (*_McastListen)(int, const address &) = _McastListenOldAPI;
#ifndef MCAST_JOIN_GROUP
#define MCAST_JOIN_GROUP 42
#endif
#ifndef MCAST_JOIN_SOURCE_GROUP
#define MCAST_JOIN_SOURCE_GROUP 46
#define MCAST_LEAVE_SOURCE_GROUP 47
#endif
#ifndef MCAST_FILTER
#define MCAST_FILTER 48
#endif
// Since some GLIBCs include this definitions, and others don't (i'm not even
// talking about BSDs) we instead define them localy to avoid definition colisions
struct _loc_group_req {
uint32_t gr_interface;
struct sockaddr_storage gr_group;
};
struct _loc_group_source_req {
uint32_t gsr_interface;
struct sockaddr_storage gsr_group;
struct sockaddr_storage gsr_source;
};
struct _loc_group_filter {
uint32_t gf_interface;
struct sockaddr_storage gf_group;
uint32_t gf_fmode;
uint32_t gf_numsrc;
struct sockaddr_storage gf_slist[1];
};
static bool set_address(sockaddr_storage &t, const address &addr) {
if (addr.family() == AF_INET)
memcpy(&t, addr.v4(), addr.addrlen());
else if (addr.family() == AF_INET6)
memcpy(&t, addr.v6(), addr.addrlen());
else
return false;
return true;
}
void MulticastStartup() {
int sock = socket(AF_INET, SOCK_DGRAM, 0);
if (sock > 0) {
_loc_group_filter flt;
memset(&flt, 0, sizeof(flt));
socklen_t fltlen = sizeof(flt);
// Check if OS supports MCAST_FILTER
if (getsockopt(sock, IPPROTO_IP, MCAST_FILTER, &flt, &fltlen) == 0
&& errno != ENOPROTOOPT) {
if (verbose)
info("Using new Multicast Filter API");
_McastListen = _McastListenNewAPI;
}
close(sock);
}
}
int _McastListenNewAPI(int sock, const address &grpaddr) {
_loc_group_req grp;
memset(&grp, 0, sizeof(grp));
grp.gr_interface = mcastInterface;
set_address(grp.gr_group, grpaddr);
return setsockopt(sock, grpaddr.optlevel(), MCAST_JOIN_GROUP, &grp, sizeof(grp));
}
int _McastListenOldAPI(int sock, const address &grpaddr) {
if (grpaddr.family() == AF_INET6) {
ipv6_mreq mreq;
mreq.ipv6mr_interface = mcastInterface;
mreq.ipv6mr_multiaddr = grpaddr.v6()->sin6_addr;
return setsockopt(sock, IPPROTO_IPV6, IPV6_JOIN_GROUP, &mreq, sizeof(mreq));
} else {
ip_mreq mreq;
memset(&mreq, 0, sizeof(mreq));
// Specifying the interface doesn't work, there's ip_mreqn in linux..
// but what about other OSs? -hugo
mreq.imr_multiaddr = grpaddr.v4()->sin_addr;
return setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq));
}
}
int MulticastListen(int sock, const address &grpaddr) {
return (*_McastListen)(sock, grpaddr);
}
static int SSMJoinLeave(int sock, int type, const address &grpaddr, const address &srcaddr) {
_loc_group_source_req req;
memset(&req, 0, sizeof(req));
req.gsr_interface = mcastInterface;
set_address(req.gsr_group, grpaddr);
set_address(req.gsr_source, srcaddr);
return setsockopt(sock, srcaddr.optlevel(), type, &req, sizeof(req));
}
int SSMJoin(int sock, const address &grpaddr, const address &srcaddr) {
return SSMJoinLeave(sock, MCAST_JOIN_SOURCE_GROUP, grpaddr, srcaddr);
}
int SSMLeave(int sock, const address &grpaddr, const address &srcaddr) {
return SSMJoinLeave(sock, MCAST_LEAVE_SOURCE_GROUP, grpaddr, srcaddr);
}
int SetupSocket(const address &addr, bool shouldbind, bool ssm) {
int af_family = addr.family();
int level = addr.optlevel();
int sock = socket(af_family, SOCK_DGRAM, 0);
if (sock < 0) {
perror("Failed to create multicast socket");
return -1;
}
int on = 1;
if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) != 0) {
perror("setsockopt");
return -1;
}
if (shouldbind) {
if (bind(sock, addr.saddr(), addr.addrlen()) != 0) {
perror("Failed to bind multicast socket");
return -1;
}
}
#ifdef SO_TIMESTAMP
if (setsockopt(sock, SOL_SOCKET, SO_TIMESTAMP, &on, sizeof(on)) != 0) {
perror("setsockopt(SO_TIMESTAMP)");
return -1;
}
#endif
int type = level == IPPROTO_IPV6 ?
#ifdef IPV6_RECVHOPLIMIT
IPV6_RECVHOPLIMIT
#else
IPV6_HOPLIMIT
#endif
:
#ifdef IP_RECVTTL
IP_RECVTTL;
#else
IP_TTL;
#endif
if (setsockopt(sock, level, type, &on, sizeof(on)) != 0) {
perror("receiving hop limit/ttl setsockopt()");
return -1;
}
if (!SetHops(sock, addr, defaultTTL)) {
perror("SetHops");
return -1;
}
if (!ssm && addr.is_multicast()) {
if (MulticastListen(sock, addr) != 0) {
perror("Failed to join multicast group");
return -1;
}
}
return sock;
}
bool SetHops(int sock, const address &addr, int ttl) {
if (addr.optlevel() == IPPROTO_IPV6) {
if (setsockopt(sock, addr.optlevel(), IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) != 0) {
return false;
}
} else {
TTLType _ttl = ttl;
if (setsockopt(sock, addr.optlevel(), IP_MULTICAST_TTL, &_ttl, sizeof(_ttl)) != 0) {
return false;
}
}
return true;
}
bool RequireToAddress(int sock, const address &addr) {
#ifdef IPV6_PKTINFO
if (addr.family() == AF_INET6) {
int on = 1;
return setsockopt(sock, IPPROTO_IPV6, IPV6_PKTINFO, &on, sizeof(on)) == 0;
}
#endif
return true;
}
int RecvMsg(int sock, address &from, address &to, uint8_t *buffer, int buflen, int &ttl, uint64_t &ts) {
int len;
struct msghdr msg;
struct iovec iov;
uint8_t ctlbuf[64];
from.set_family(beaconUnicastAddr.family());
msg.msg_name = (char *)from.saddr();
msg.msg_namelen = from.addrlen();
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = (char *)ctlbuf;
msg.msg_controllen = sizeof(ctlbuf);
msg.msg_flags = 0;
iov.iov_base = (char *)buffer;
iov.iov_len = buflen;
len = recvmsg(sock, &msg, 0);
if (len < 0)
return len;
ts = 0;
ttl = 127;
to = beaconUnicastAddr;
if (msg.msg_controllen > 0) {
for (cmsghdr *hdr = CMSG_FIRSTHDR(&msg); hdr; hdr = CMSG_NXTHDR(&msg, hdr)) {
if (hdr->cmsg_level == IPPROTO_IPV6 && hdr->cmsg_type == IPV6_HOPLIMIT) {
ttl = *(uint8_t *)CMSG_DATA(hdr);
#ifdef IPV6_PKTINFO
} else if (hdr->cmsg_level == IPPROTO_IPV6 && hdr->cmsg_type == IPV6_PKTINFO) {
if (hdr->cmsg_len == CMSG_LEN(sizeof(in6_pktinfo))) {
in6_pktinfo *pktinfo = (in6_pktinfo *)CMSG_DATA(hdr);
to.set_family(AF_INET6);
to.v6()->sin6_addr = pktinfo->ipi6_addr;
}
#endif
#ifdef IP_RECVTTL
} else if (hdr->cmsg_level == IPPROTO_IP && hdr->cmsg_type == IP_RECVTTL) {
ttl = *(uint8_t *)CMSG_DATA(hdr);
#endif
} else if (hdr->cmsg_level == IPPROTO_IP && hdr->cmsg_type == IP_TTL) {
ttl = *(uint8_t *)CMSG_DATA(hdr);
#ifdef SO_TIMESTAMP
} else if (hdr->cmsg_level == SOL_SOCKET && hdr->cmsg_type == SO_TIMESTAMP) {
timeval *tv = (timeval *)CMSG_DATA(hdr);
ts = tv->tv_sec;
ts *= 1000;
ts += tv->tv_usec / 1000;
#endif
}
}
}
if (!ts) {
ts = get_time_of_day();
}
return len;
}
int SendTo(int sock, const uint8_t *buffer, int len, const address &from, const address &to) {
#ifdef IPV6_PKTINFO
if (from.family() == AF_INET6) {
uint8_t ctlbuf[CMSG_SPACE(sizeof(in6_pktinfo))];
cmsghdr *chdr = (cmsghdr *)ctlbuf;
chdr->cmsg_len = CMSG_LEN(sizeof(in6_pktinfo));
chdr->cmsg_level = IPPROTO_IPV6;
chdr->cmsg_type = IPV6_PKTINFO;
in6_pktinfo *info = (in6_pktinfo *)CMSG_DATA(chdr);
info->ipi6_addr = from.v6()->sin6_addr;
info->ipi6_ifindex = 0;
msghdr msg;
iovec iov;
msg.msg_name = (char *)to.saddr();
msg.msg_namelen = to.addrlen();
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = (char *)ctlbuf;
msg.msg_controllen = sizeof(ctlbuf);
msg.msg_flags = 0;
iov.iov_base = (char *)buffer;
iov.iov_len = len;
return sendmsg(sock, &msg, 0);
}
#endif
return sendto(sock, buffer, len, 0, to.saddr(), to.addrlen());
}
address::address() {
memset(&stor, 0, sizeof(stor));
}
address::address(int family) {
memset(&stor, 0, sizeof(stor));
stor.ss_family = family;
}
address::address(const address &original)
: stor(original.stor) {
}
sockaddr_in *address::v4() { return (sockaddr_in *)&stor; }
sockaddr_in6 *address::v6() { return (sockaddr_in6 *)&stor; }
const sockaddr_in *address::v4() const { return (const sockaddr_in *)&stor; }
const sockaddr_in6 *address::v6() const { return (const sockaddr_in6 *)&stor; }
sockaddr *address::saddr() { return (sockaddr *)&stor; }
const sockaddr *address::saddr() const { return (const sockaddr *)&stor; }
int address::family() const {
return stor.ss_family;
}
bool address::set_family(int family) {
if (family != AF_INET && family != AF_INET6)
return false;
stor.ss_family = family;
return true;
}
int address::optlevel() const {
return stor.ss_family == AF_INET6 ? IPPROTO_IPV6 : IPPROTO_IP;
}
int address::addrlen() const {
return stor.ss_family == AF_INET6 ? sizeof(sockaddr_in6) : sizeof(sockaddr_in);
}
bool address::parse(const char *str, bool multicast, bool addport) {
char tmp[128];
strncpy(tmp, str, sizeof(tmp));
char *port = strchr(tmp, '/');
if (port) {
*port = 0;
port ++;
} else if (addport) {
port = (char *)defaultPort;
}
int cres;
addrinfo hint, *rres, *res;
memset(&hint, 0, sizeof(hint));
hint.ai_family = forceFamily;
hint.ai_socktype = SOCK_DGRAM;
if ((cres = getaddrinfo(*tmp ? tmp : 0, port, &hint, &rres)) != 0) {
info("getaddrinfo failed: %s", gai_strerror(cres));
return false;
}
for (res = rres; res; res = res->ai_next) {
set(res->ai_addr);
if (multicast) {
if (is_multicast())
break;
} else if (!is_unspecified())
break;
}
freeaddrinfo(rres);
if (!res) {
info("Failed to resolve %s", tmp);
return false;
}
return true;
}
bool address::set_addr(const char *addr) {
if (stor.ss_family == AF_INET) {
if (inet_pton(AF_INET, addr, &v4()->sin_addr) <= 0)
return false;
} else if (stor.ss_family == AF_INET6) {
if (inet_pton(AF_INET6, addr, &v6()->sin6_addr) <= 0)
return false;
} else {
return false;
}
return true;
}
bool address::set_port(int port) {
if (stor.ss_family == AF_INET) {
v4()->sin_port = htons(port);
} else if (stor.ss_family == AF_INET6) {
v6()->sin6_port = htons(port);
} else {
return false;
}
return true;
}
bool address::is_multicast() const {
if (stor.ss_family == AF_INET6)
return IN6_IS_ADDR_MULTICAST(&v6()->sin6_addr);
else if (stor.ss_family == AF_INET)
return IN_CLASSD(htonl(v4()->sin_addr.s_addr));
return false;
}
bool address::is_unspecified() const {
if (stor.ss_family == AF_INET6)
return IN6_IS_ADDR_UNSPECIFIED(&v6()->sin6_addr);
else if (stor.ss_family == AF_INET)
return v4()->sin_addr.s_addr == 0;
return true;
}
int address::port() const {
if (stor.ss_family == AF_INET6)
return ntohs(v6()->sin6_port);
else if (stor.ss_family == AF_INET)
return ntohs(v4()->sin_port);
return -1;
}
char *address::to_string(char *str, size_t len, bool printport) const {
uint16_t port;
if (stor.ss_family == AF_INET6) {
inet_ntop(AF_INET6, &v6()->sin6_addr, str, len);
port = ntohs(v6()->sin6_port);
} else if (stor.ss_family == AF_INET) {
inet_ntop(AF_INET, &v4()->sin_addr, str, len);
port = ntohs(v4()->sin_port);
} else {
return NULL;
}
if (printport)
snprintf(str + strlen(str), len - strlen(str), "/%u", port);
return str;
}
std::string address::to_string(bool printport) const {
char tmp[128];
return std::string(to_string(tmp, sizeof(tmp), printport));
}
int address::fromsocket(int sock)
{
socklen_t addrlen = this->addrlen();
return getsockname(sock, this->saddr(), &addrlen);
}
bool address::is_equal(const address &a) const {
if (stor.ss_family != a.stor.ss_family)
return false;
if (stor.ss_family == AF_INET6)
return memcmp(&v6()->sin6_addr, &a.v6()->sin6_addr, sizeof(in6_addr)) == 0;
else if (stor.ss_family == AF_INET)
return v4()->sin_addr.s_addr == a.v4()->sin_addr.s_addr;
return false;
}
int address::compare(const address &a) const {
return memcmp(&stor, &a.stor, sizeof(stor));
}
void address::set(const sockaddr *sa) {
stor.ss_family = sa->sa_family;
if (stor.ss_family == AF_INET6) {
v6()->sin6_addr = ((const sockaddr_in6 *)sa)->sin6_addr;
v6()->sin6_port = ((const sockaddr_in6 *)sa)->sin6_port;
} else {
v4()->sin_addr = ((const sockaddr_in *)sa)->sin_addr;
v4()->sin_port = ((const sockaddr_in *)sa)->sin_port;
}
}
bool address::copy_address(const address &source) {
if (family() != source.family())
return false;
if (stor.ss_family == AF_INET6)
v6()->sin6_addr = source.v6()->sin6_addr;
else
v4()->sin_addr = source.v4()->sin_addr;
return true;
}
uint64_t get_timestamp() {
struct tms tmp;
uint64_t v = times(&tmp);
return (v * 1000) / sysconf(_SC_CLK_TCK);
}
uint64_t get_time_of_day() {
struct timeval tv;
uint64_t timestamp;
if (gettimeofday(&tv, 0) != 0)
return 0;
timestamp = tv.tv_sec;
timestamp *= 1000;
timestamp += tv.tv_usec / 1000;
return timestamp;
}
int
dbeacon_daemonize(const char *pidfile)
{
if (chdir("/") < 0)
return -1;
int ch = fork();
if (ch < 0)
return -1;
/* exit parent */
if (ch != 0)
_exit(0);
/* child, lets prepare for daemonizing */
int null = open("/dev/null", O_RDWR);
if (null >= 0) {
dup2(null, 0);
dup2(null, 1);
dup2(null, 2);
}
umask(022);
setsid();
if (pidfile) {
FILE *f = fopen(pidfile, "w");
if (f) {
fprintf(f, "%u\n", getpid());
fclose(f);
} else {
d_log(LOG_ERR, "Failed to open PID file to write.");
}
}
return 0;
}
address get_local_address_for(const address &remote)
{
int tmpSock = socket(remote.family(), SOCK_DGRAM, 0);
if (tmpSock < 0) {
perror("Failed to create socket to discover local addr");
exit(-1);
}
if (connect(tmpSock, remote.saddr(), remote.addrlen()) != 0) {
perror("Failed to connect multicast socket");
exit(-1);
}
address result(remote.family());
if (result.fromsocket(tmpSock) < 0) {
perror("getsockname");
exit(-1);
}
close(tmpSock);
return result;
}