tobast/congestvpn
1
0
Fork 0
Code Issues 3 Pull requests Releases Wiki Activity

C rewrite: phase out exceptions

Browse source
This commit is contained in:
Théophile Bastian 2020-07-22 19:09:27 +02:00
parent 7c1e5562f2
commit ecc996f3f0
12 changed files with 67 additions and 149 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

34
TunDevice.cpp
View file

@ -18,8 +18,8 @@ TunDevice::TunDevice(const std::string& dev)
int fd;
if( (fd = open("/dev/net/tun", O_RDWR)) < 0 ) {
throw TunDevice::InitializationError(
"Cannot open /dev/net/tun", errno, true);
perror("Tun device: cannot open /dev/net/tun: ");
exit(1);
}
memset(&ifr, 0, sizeof(ifr));
@ -31,15 +31,17 @@ TunDevice::TunDevice(const std::string& dev)
*/
ifr.ifr_flags = IFF_TUN | IFF_NO_PI;
if(!dev.empty()) {
if(dev.size() >= IFNAMSIZ - 2)
throw TunDevice::InitializationError("Device name is too long.");
if(dev.size() >= IFNAMSIZ - 2) {
fprintf(stderr, "Tun device: device name is too long.\n");
exit(1);
}
strncpy(ifr.ifr_name, dev.c_str(), IFNAMSIZ-1);
}
if(ioctl(fd, TUNSETIFF, (void *) &ifr) < 0){
close(fd);
throw TunDevice::InitializationError(
"Tunnel interface failed [TUNSETIFF]", errno, true);
perror("Tun device: tunnel interface failed [TUNSETIFF]: ");
exit(1);
}
_dev_name = ifr.ifr_name;
_fd = fd;
@ -50,16 +52,16 @@ TunDevice::TunDevice(const std::string& dev)
if(ioctl(sockfd, SIOCGIFFLAGS, (void*) &ifr) < 0) {
close(fd);
close(sockfd);
throw TunDevice::InitializationError(
"Could not get tunnel interface flags", errno, true);
perror("Tun device: could not get tunnel interface flags: ");
exit(1);
}
ifr.ifr_flags |= IFF_UP | IFF_RUNNING;
if(ioctl(sockfd, SIOCSIFFLAGS, (void*) &ifr) < 0) {
close(fd);
close(sockfd);
throw TunDevice::InitializationError(
"Could not bring tunnel interface up", errno, true);
perror("Tun device: could not bring tunnel interface up: ");
exit(1);
}
close(sockfd);
@ -102,8 +104,8 @@ size_t TunDevice::poll_packet(char* read_buffer, size_t buf_size, int timeout) {
if(poll_rc < 0) {
if(errno == EINTR) // Interrupt.
return 0;
throw TunDevice::NetError(
"Error polling from interface", errno, true);
perror("Tun device: error polling from interface: ");
exit(1);
}
else if(poll_rc == 0 || (_poll_fd.revents & POLLIN) == 0) {
// Nothing to read
@ -116,8 +118,8 @@ size_t TunDevice::poll_packet(char* read_buffer, size_t buf_size, int timeout) {
size_t TunDevice::read(char* read_buffer, size_t buf_size) {
int nread = ::read(_fd, read_buffer, buf_size);
if(nread < 0) {
throw TunDevice::NetError(
"Error reading from interface", errno, true);
perror("Tun device: error reading from interface: ");
exit(1);
}
_last_read_size = nread;
return _last_read_size;
@ -126,8 +128,8 @@ size_t TunDevice::read(char* read_buffer, size_t buf_size) {
size_t TunDevice::write(const char* data, size_t len) {
int nwritten = ::write(_fd, data, len);
if(nwritten < 0) {
throw TunDevice::NetError(
"Error writing to interface: ", errno, true);
perror("Tun device: error writing to interface: ");
exit(1);
}
return nwritten;
}

17
TunDevice.hpp
View file

@ -6,23 +6,6 @@
class TunDevice {
public:
class InitializationError : public MsgException {
public:
InitializationError(
const std::string& msg,
int code=0,
bool is_perror=false)
: MsgException(msg, code, is_perror) {}
};
class NetError : public MsgException {
public:
NetError(
const std::string& msg,
int code=0,
bool is_perror=false)
: MsgException(msg, code, is_perror) {}
};
TunDevice(const std::string& dev);
~TunDevice();

16
UdpVpn.cpp
View file

@ -24,8 +24,10 @@ UdpVpn::UdpVpn()
_tun_dev.set_mtu(VpnPacket::get_tunnelled_mtu(_vpn_mtu));
_socket = socket(AF_INET6, SOCK_DGRAM, 0);
if(_socket < 0)
throw UdpVpn::InitializationError("Cannot create socket", errno, true);
if(_socket < 0) {
perror("UdpVpn: cannot create socket: ");
exit(1);
}
}
UdpVpn::~UdpVpn() {
@ -58,8 +60,8 @@ void UdpVpn::run() {
if(rc < 0) {
if(errno == EINTR) // Interrupt.
continue;
throw UdpVpn::NetError(
"Error polling from interface", errno, true);
perror("UdpVpn: error polling from interface: ");
exit(1);
}
// ## Check periodic actions
@ -124,8 +126,10 @@ size_t UdpVpn::read_from_udp(char* buffer, size_t len,
nread = recvfrom(_socket, buffer, len, 0,
(struct sockaddr*) &peer_addr, &peer_addr_len);
if(nread < 0)
throw UdpVpn::NetError("Cannot receive datagram", errno, true);
if(nread < 0) {
perror("UdpVpn: cannot receive datagram: ");
exit(1);
}
if(nread == 0)
return 0;

17
UdpVpn.hpp
View file

@ -13,23 +13,6 @@
class UdpVpn {
public:
class InitializationError : public MsgException {
public:
InitializationError(
const std::string& msg,
int code=0,
bool is_perror=false)
: MsgException(msg, code, is_perror) {}
};
class NetError : public MsgException {
public:
NetError(
const std::string& msg,
int code=0,
bool is_perror=false)
: MsgException(msg, code, is_perror) {}
};
UdpVpn();
virtual ~UdpVpn();

3
UdpVpnServer.cpp
View file

@ -51,7 +51,8 @@ void UdpVpnServer::bind(const struct in6_addr& bind_addr6, in_port_t port) {
rc = ::bind(
_socket, (const struct sockaddr*)&_bind_addr, sizeof(_bind_addr));
if(rc < 0) {
throw UdpVpn::InitializationError("Cannot bind socket", errno, true);
perror("UdpVpn: cannot bind socket: ");
exit(1);
}
debugf("> Listening on port %d\n", port);

6
VpnPacket.cpp
View file

@ -79,8 +79,10 @@ void VpnPacket::upon_reception() {
}
uint32_t VpnPacket::next_seqno() {
if(!_peer)
throw PeerNotSet();
if(!_peer) {
fprintf(stderr, "ERROR: trying to get seqno without peer.\n");
return 0;
}
return _peer->next_seqno();
}

2
VpnPacket.hpp
View file

@ -3,7 +3,6 @@
/** A packet to be transmitted or received over the VPN socket */
#include <stdlib.h>
#include <exception>
#include "ip_header.hpp"
@ -50,7 +49,6 @@ class VpnPacketTLV;
class VpnPacket {
public:
static const size_t VPN_HEADER_BYTES;
class PeerNotSet: public std::exception {};
VpnPacket(size_t mtu, bool inbound);
~VpnPacket();

6
VpnPeer.cpp
View file

@ -69,8 +69,10 @@ size_t VpnPeer::write(const char* data, size_t len) {
nsent = sendto(_vpn->get_socket_fd(), data, len, MSG_CONFIRM,
(const struct sockaddr*) &_ext_addr, sizeof(_ext_addr));
if(nsent < 0)
throw NetError("Could not send UDP packet", errno, true);
if(nsent < 0) {
perror("Could not send UDP packet: ");
exit(1);
}
_tot_bytes_sent += nsent;

9
VpnPeer.hpp
View file

@ -68,15 +68,6 @@ class RTTLogger {
class VpnPeer {
public:
class NetError : public MsgException {
public:
NetError(
const std::string& msg,
int code=0,
bool is_perror=false)
: MsgException(msg, code, is_perror) {}
};
/// Logs the loss reports sent by the remote peer
struct LossReports {
uint32_t prev_seqno, last_seqno;

69
main.cpp
View file

@ -100,52 +100,41 @@ int main(int argc, char** argv) {
signal(SIGINT, stop_sig_handler);
signal(SIGUSR1, dump_sig_handler);
try {
if(program_options.listen && program_options.has_peer) {
if(program_options.listen && program_options.has_peer) {
fprintf(stderr,
"ERROR: Cannot be a server and a client at the same time "
"-- provide either -l or -s.\n");
return 1;
}
if(program_options.listen) {
vpn_instance = new UdpVpnServer(
program_options.bind_addr, program_options.bind_port);
} else if(program_options.has_peer) {
if(program_options.server_port == 0) {
fprintf(stderr,
"ERROR: Cannot be a server and a client at the same time "
"-- provide either -l or -s.\n");
return 1;
}
if(program_options.listen) {
vpn_instance = new UdpVpnServer(
program_options.bind_addr, program_options.bind_port);
} else if(program_options.has_peer) {
if(program_options.server_port == 0) {
fprintf(stderr,
"ERROR: A client instance must be given a server port "
"-- please provide -p.\n");
return 1;
}
struct sockaddr_in6 server_addr;
server_addr.sin6_family = AF_INET6; memcpy(&server_addr.sin6_addr, &program_options.server_addr,
sizeof(server_addr.sin6_addr));
server_addr.sin6_port = htons(program_options.server_port);
vpn_instance = new UdpVpnClient(server_addr);
} else {
fprintf(stderr,
"ERROR: Must be either a server or a client "
"-- provide either -l or -s.\n");
"ERROR: A client instance must be given a server port "
"-- please provide -p.\n");
return 1;
}
printf("Starting to listen...\n");
vpn_instance->run();
struct sockaddr_in6 server_addr;
server_addr.sin6_family = AF_INET6; memcpy(&server_addr.sin6_addr, &program_options.server_addr,
sizeof(server_addr.sin6_addr));
server_addr.sin6_port = htons(program_options.server_port);
delete vpn_instance;
printf("Shutting down.\n");
} catch(const TunDevice::InitializationError& exn) {
fprintf(stderr, "TUN INIT ERROR: %s\n", exn.what());
} catch(const TunDevice::NetError& exn) {
fprintf(stderr, "TUN NET ERROR: %s\n", exn.what());
} catch(const UdpVpn::InitializationError& exn) {
fprintf(stderr, "VPN INIT ERROR: %s\n", exn.what());
} catch(const UdpVpn::NetError& exn) {
fprintf(stderr, "VPN NET ERROR: %s\n", exn.what());
vpn_instance = new UdpVpnClient(server_addr);
} else {
fprintf(stderr,
"ERROR: Must be either a server or a client "
"-- provide either -l or -s.\n");
return 1;
}
printf("Starting to listen...\n");
vpn_instance->run();
delete vpn_instance;
printf("Shutting down.\n");
return 0;
}

17
util.cpp
View file

@ -109,20 +109,3 @@ bool equal_to<in6_addr>::operator()(
return memcmp(lhs.s6_addr, rhs.s6_addr, sizeof(lhs.s6_addr)) == 0;
}
}
MsgException::MsgException(const std::string& msg, int code, bool is_perror)
: _msg(msg), _code(code)
{
_what = _msg;
if(_code != 0) {
if(is_perror) {
_what += ": ";
_what += strerror(errno);
}
char remainder[20];
sprintf(remainder, " (code %d)", _code);
_what += remainder;
}
}

20
util.hpp
View file

@ -1,6 +1,5 @@
#pragma once
#include <exception>
#include <string>
#include <netinet/in.h>
@ -96,22 +95,3 @@ namespace std {
bool operator()(const in6_addr& lhs, const in6_addr& rhs) const;
};
}
/** MsgException -- an exception bearing a passed explanation message
*
* If `is_perror` is true, then the `strerror` corresponding message is appened
* to the message in `what()`.
*/
class MsgException : public std::exception {
public:
MsgException(const std::string& msg, int code=0, bool is_perror=false);
int errcode() const noexcept { return _code; }
const char* what() const noexcept { return _what.c_str(); };
private:
std::string _msg;
int _code;
std::string _what;
};