iptogeo/src/server.c
2024-08-31 14:35:40 +02:00

632 lines
19 KiB
C

/*
Copyright 2016 Grégory Soutadé
This file is part of iptogeo.
iptogeo is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
iptogeo is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with iptogeo. If not, see <http://www.gnu.org/licenses/>.
*/
#define _GNU_SOURCE 1 // for POLLRDHUP && syncfs
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/select.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <netdb.h>
#include <time.h>
#include <syslog.h>
#include <signal.h>
#include <stdio.h>
#include <unistd.h>
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include <poll.h>
#include <fcntl.h>
#ifdef USE_SECCOMP
#include <seccomp.h>
#endif
#include "ip_to_geo.h"
#include "protocol.h"
#define WAIT_TIME 100
#define MAX_WAIT_TIME 500
#define MAX_LISTENING_SOCKETS 16
typedef struct {
int socket;
time_t timeout; // in µs
int nb_remaining_requests;
} socket_ctx_t;
typedef struct thread_ctx_s{
struct thread_ctx_s* prev;
struct thread_ctx_s* next;
pthread_t thread;
socket_ctx_t* sockets;
int nb_cur_sockets;
int nb_available_sockets;
int max_timeout; // in ms
int max_sockets;
int stop;
int quiet;
pthread_mutex_t mutex;
struct pollfd * pollfds;
} thread_ctx_t;
static pthread_mutex_t s_fastmutex = PTHREAD_MUTEX_INITIALIZER;
static thread_ctx_t* s_last_thread = NULL;
static int s_server_sockets[MAX_LISTENING_SOCKETS];
static int s_nb_server_sockets = 0;
static int s_stop = 0;
void sigint(int sig)
{
int i;
syslog(LOG_WARNING, "signal received, stopping threads");
s_stop = 1;
for (i=0; i<s_nb_server_sockets; i++)
shutdown(s_server_sockets[i], SHUT_RDWR);
}
static int check_request(request_t* req)
{
if (req->magic != REQ_MAGIC)
return REQ_ERR_BAD_MAGIC;
if (req->version != REQ_VERSION)
return REQ_ERR_BAD_VERSION;
if (req->ip_type != REQ_IPV4 &&
req->ip_type != REQ_IPV6)
return REQ_ERR_BAD_IP_VERSION;
if (req->ip_type != REQ_IPV4 && req->ip_type != REQ_IPV6)
return REQ_ERR_UNSUPPORTED_IP_VERSION;
if (req->req != REQ_REQ)
return REQ_ERR_BAD_REQ_FIELD;
return REQ_ERR_NO_ERR;
}
static int handle_request(thread_ctx_t* thread_ctx, int socket)
{
request_t req;
const uint8_t* geo;
int sent=0;
int ret = read(socket, &req, sizeof(req));
// Socket closed
if (ret == 0)
{
if (thread_ctx->quiet < 0)
syslog(LOG_DEBUG, "Socket %d closed", socket);
return 1;
}
if (thread_ctx->quiet < 0)
syslog(LOG_DEBUG, "New request");
if (ret != sizeof(req))
{
if (thread_ctx->quiet < 0)
syslog(LOG_DEBUG, "Invalid request size %d", ret);
return -1;
}
ret = check_request(&req);
req.req = REQ_RESP;
if (ret)
{
req.err = ret;
if (thread_ctx->quiet < 0)
syslog(LOG_DEBUG, "Request error %d", ret);
}
else
{
if (thread_ctx->quiet < 0)
{
char dst[64];
inet_ntop((req.ip_type == REQ_IPV4)?AF_INET:AF_INET6, req.ip, dst, sizeof(dst));
syslog(LOG_DEBUG, "Request for %s from socket %d", dst, socket);
}
geo = ip_to_geo(req.ip, req.ip_type);
if (!geo)
{
req.err = REQ_IP_NOT_FOUND;
if (thread_ctx->quiet < 0)
syslog(LOG_DEBUG, "Not found");
}
else
{
req.err = REQ_ERR_NO_ERR;
geo = get_country_code(geo);
if (thread_ctx->quiet < 0)
syslog(LOG_DEBUG, "Res %s", geo);
req.country_code[0] = geo[0];
req.country_code[1] = geo[1];
req.country_code[2] = 0;
req.country_code[3] = 0;
}
}
for (sent=0; sent < sizeof(req); sent += ret)
{
ret = write(socket, &((uint8_t*)&req)[sent], sizeof(req)-sent);
if (ret < 0)
return -1;
}
return 0;
}
static void delete_thread(thread_ctx_t* thread_ctx)
{
int i;
pthread_mutex_lock(&s_fastmutex);
thread_ctx->nb_available_sockets = 0;
if (thread_ctx->quiet < 0)
syslog(LOG_DEBUG, "Delete thread %p", thread_ctx);
for(i=0; i<thread_ctx->nb_cur_sockets; i++)
{
if (thread_ctx->sockets[i].timeout > 0)
{
close (thread_ctx->sockets[i].socket);
}
}
free(thread_ctx->sockets);
free(thread_ctx->pollfds);
if (thread_ctx->next)
thread_ctx->next->prev = thread_ctx->prev;
if (thread_ctx->prev)
thread_ctx->prev->next = thread_ctx->next;
if (thread_ctx == s_last_thread)
s_last_thread = thread_ctx->next;
pthread_mutex_unlock(&s_fastmutex);
free(thread_ctx);
}
static inline void close_socket(socket_ctx_t* socket)
{
socket->timeout = -1;
close(socket->socket);
}
#define POLL_ERR_MASK (POLLRDHUP|POLLERR|POLLHUP|POLLNVAL)
static void* thread_loop(void* param)
{
thread_ctx_t* ctx = (thread_ctx_t*)param;
int i, ret, nfds, nb_cur_sockets, nb_available_sockets, poll_idx;
struct timeval time1, time2, time_res;
int wait_time = WAIT_TIME;
while (!ctx->stop)
{
nfds = 0;
pthread_mutex_lock(&ctx->mutex);
nb_cur_sockets = ctx->nb_cur_sockets;
nb_available_sockets = ctx->nb_available_sockets;
pthread_mutex_unlock(&ctx->mutex);
for(i=0; i<nb_cur_sockets; i++)
{
if (ctx->sockets[i].timeout > 0)
{
ctx->pollfds[nfds].fd = ctx->sockets[i].socket;
ctx->pollfds[nfds].events = POLLIN|POLL_ERR_MASK;
nfds++;
}
}
if (!nfds)
{
/*
No more active socket for this thread
nor available slots
*/
if (!nb_available_sockets)
break;
if (wait_time < MAX_WAIT_TIME)
wait_time += WAIT_TIME;
usleep(wait_time);
continue;
}
else
wait_time = WAIT_TIME;
gettimeofday(&time1, NULL);
ret = poll(ctx->pollfds, nfds, ctx->max_timeout);
gettimeofday(&time2, NULL);
// Timeout, remove all current sockets
if (ret == 0)
{
if (ctx->quiet < 0)
syslog(LOG_DEBUG, "Timeout");
for(i=0; i<nb_cur_sockets; i++)
{
if (ctx->sockets[i].timeout > 0)
close_socket(&ctx->sockets[i]);
}
}
else if (ret < 0)
{
if (!s_stop && !ctx->stop)
syslog(LOG_WARNING, "poll has errors (%m)\n");
break;
}
else
{
timersub(&time2, &time1, &time_res);
poll_idx = -1;
for(i=0; i<nb_cur_sockets; i++)
{
if (ctx->sockets[i].timeout < 0) continue;
poll_idx++;
if (ctx->pollfds[poll_idx].fd != ctx->sockets[i].socket)
{
if (ctx->quiet < 0)
syslog(LOG_ERR, "Socket not found but present in poll fds");
continue;
}
// Error
if (ctx->pollfds[poll_idx].revents & POLL_ERR_MASK)
{
if (ctx->quiet < 0)
syslog(LOG_ERR, "Error (or closed) socket %d", ctx->sockets[i].socket);
close_socket(&ctx->sockets[i]);
}
// Someone is speaking
else if (ctx->pollfds[poll_idx].revents & POLLIN)
{
ctx->sockets[i].timeout = ctx->max_timeout*1000;
ret = handle_request(ctx, ctx->sockets[i].socket);
if (ret == 1)
{
if (ctx->quiet < 0)
syslog(LOG_DEBUG, "Client has closed socket %d",
ctx->sockets[i].socket);
close_socket(&ctx->sockets[i]);
}
// No more requests accepted
else if (!ctx->sockets[i].nb_remaining_requests--)
{
if (ctx->quiet < 0)
syslog(LOG_DEBUG, "Max requests reached for socket %d",
ctx->sockets[i].socket);
syncfs(ctx->sockets[i].socket);
close_socket(&ctx->sockets[i]);
}
}
else
{
ctx->sockets[i].timeout -= (time_res.tv_sec*1000000 + time_res.tv_usec);
if (ctx->sockets[i].timeout <= 0)
close_socket(&ctx->sockets[i]);
}
}
}
};
delete_thread(ctx);
pthread_exit(NULL);
return NULL;
}
static inline thread_ctx_t* create_thread_ctx(struct gengetopt_args_info* params)
{
thread_ctx_t* thread_ctx = malloc(sizeof(*thread_ctx));
if (params->verbose_flag)
syslog(LOG_DEBUG, "Create a new thread %p", thread_ctx);
thread_ctx->sockets = malloc(sizeof(*thread_ctx->sockets)*params->sockets_per_thread_arg);
thread_ctx->pollfds = malloc(sizeof(*thread_ctx->pollfds)*params->sockets_per_thread_arg);
thread_ctx->nb_cur_sockets = 0;
thread_ctx->nb_available_sockets = params->sockets_per_thread_arg;
thread_ctx->max_timeout = params->sockets_timeout_arg*1000;
thread_ctx->stop = 0;
thread_ctx->quiet = params->quiet_flag;
if (params->verbose_flag)
thread_ctx->quiet = -1;
thread_ctx->prev = NULL;
pthread_mutex_init(&thread_ctx->mutex, NULL);
thread_ctx->next = s_last_thread;
if (s_last_thread)
s_last_thread->prev = thread_ctx;
s_last_thread = thread_ctx;
return thread_ctx;
}
static void fill_new_socket(struct gengetopt_args_info* params, int socket)
{
thread_ctx_t* thread_ctx;
int launch_thread = 0;
pthread_mutex_lock(&s_fastmutex);
thread_ctx = s_last_thread;
if (!thread_ctx || !thread_ctx->nb_available_sockets)
{
thread_ctx = create_thread_ctx(params);
launch_thread = 1;
}
pthread_mutex_unlock(&s_fastmutex);
thread_ctx->sockets[thread_ctx->nb_cur_sockets].socket = socket;
thread_ctx->sockets[thread_ctx->nb_cur_sockets].timeout = thread_ctx->max_timeout*1000; // ms -> us
thread_ctx->sockets[thread_ctx->nb_cur_sockets].nb_remaining_requests = params->client_max_requests_arg;
pthread_mutex_lock(&thread_ctx->mutex);
thread_ctx->nb_cur_sockets++;
thread_ctx->nb_available_sockets--;
pthread_mutex_unlock(&thread_ctx->mutex);
if (launch_thread)
pthread_create(&thread_ctx->thread, NULL, thread_loop, thread_ctx);
}
int daemonize(struct gengetopt_args_info* params)
{
int ret, i;
struct sockaddr_in6 sockaddr;
socklen_t sockaddr_len;
int new_socket;
void* thread_ret;
struct addrinfo hints;
struct addrinfo *result, *rp;
char buffer[64];
int on;
struct pollfd pollfds[MAX_LISTENING_SOCKETS];
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC; /* Allow IPv4 or IPv6 */
hints.ai_socktype = SOCK_STREAM; /* Datagram socket */
hints.ai_flags = (params->bind_ip_given)?0:AI_PASSIVE; /* For wildcard IP address */
hints.ai_protocol = 0; /* Any protocol */
snprintf(buffer, sizeof(buffer), "%d", params->port_arg);
ret = getaddrinfo(params->bind_ip_arg, buffer, &hints, &result);
if (ret)
{
fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(ret));
return -1;
}
for (rp=result; rp && s_nb_server_sockets < MAX_LISTENING_SOCKETS;
rp=rp->ai_next, s_nb_server_sockets++)
{
new_socket = socket(rp->ai_family,
rp->ai_socktype,
rp->ai_protocol); // Should have both TCP & UDP
if (!new_socket)
{
if (!params->quiet_flag)
fprintf(stderr, "Unable to create socket (%m)\n");
return -1;
}
s_server_sockets[s_nb_server_sockets] = new_socket;
pollfds[s_nb_server_sockets].fd = new_socket;
pollfds[s_nb_server_sockets].events = POLLIN|POLL_ERR_MASK;
on=1; setsockopt(new_socket, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on));
if (rp->ai_family == AF_INET6)
{
on=1; setsockopt(new_socket, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on));
}
memset(&sockaddr, 0, sizeof(sockaddr));
sockaddr.sin6_family = rp->ai_family; // Should detect interface type (v4 or v6)
sockaddr.sin6_port = htons(params->port_arg);
if (params->bind_ip_given)
{
ret = inet_pton(rp->ai_family, params->bind_ip_arg, &sockaddr.sin6_addr);
if (ret)
{
if (!params->quiet_flag)
fprintf(stderr, "Error with bind address %s (%m)\n", params->bind_ip_arg);
return -1;
}
}
else
sockaddr.sin6_addr = in6addr_any;
ret = bind(new_socket, (struct sockaddr *)&sockaddr, sizeof(sockaddr));
if (ret)
{
if (!params->quiet_flag)
fprintf(stderr, "Unable to bind (%m)\n");
return -2;
}
ret = listen(new_socket, params->sockets_per_thread_arg);
if (ret)
{
if (!params->quiet_flag)
fprintf(stderr, "Unable to listen (%m)\n");
return -3;
}
}
if (rp)
fprintf(stderr, "Warning, max listening sockets reached !!\n");
if (!params->no_background_flag)
{
ret = daemon(0, 0);
if (ret)
{
if (!params->quiet_flag)
fprintf(stderr, "Daemon error (%m)\n");
return -4;
}
}
openlog("ip_to_geod", 0, LOG_DAEMON);
syslog(LOG_INFO, "ip_togeod started\n");
signal(SIGINT, sigint);
signal(SIGUSR1, sigint);
signal(SIGUSR2, sigint);
#ifdef USE_SECCOMP
scmp_filter_ctx seccomp_ctx = seccomp_init(SCMP_ACT_KILL/*SCMP_ACT_TRAP*/);
if (seccomp_ctx == NULL)
{
syslog(LOG_ERR, "unable to initialize seccomp\n");
return -5;
}
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(poll), 0);
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(read), 0);
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(write), 0);
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(close), 0);
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(shutdown), 0);
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(accept), 0);
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(syncfs), 0);
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(nanosleep), 0);
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(restart_syscall), 0); // for usleep
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(rt_sigreturn), 0); // for signal handler
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(syslog), 0);
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(sendto), 0); // For syslog
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(open), 1, SCMP_A1(SCMP_CMP_EQ , O_RDONLY|O_CLOEXEC));
// For threads
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(mmap), 0);
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(munmap), 0);
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(mprotect), 0);
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(clone), 0);
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(fstat), 0);
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(access), 0);
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(exit), 0);
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(exit_group), 0);
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(set_robust_list), 0);
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(madvise), 0);
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(munlock), 0);
seccomp_rule_add(seccomp_ctx, SCMP_ACT_ALLOW, SCMP_SYS(futex), 0);
ret = seccomp_load(seccomp_ctx);
if (ret < 0)
{
syslog(LOG_ERR, "Error seccomp load %d\n", ret);
return -6;
}
#endif
while (!s_stop)
{
ret = poll(pollfds, s_nb_server_sockets, 1000);
if (ret < 0)
{
if (!s_stop)
syslog(LOG_ERR, "main poll err %d", ret);
break;
}
if (ret == 0) continue; // timeout
for (i=0; i<s_nb_server_sockets; i++)
{
if (pollfds[i].revents & POLL_ERR_MASK)
{
if (!s_stop)
syslog(LOG_ERR, "Error with main socket %d (%m)", s_server_sockets[i]);
close (s_server_sockets[i]);
continue;
}
if (!(pollfds[i].revents & POLLIN)) continue;
sockaddr_len = sizeof(sockaddr);
new_socket = accept(s_server_sockets[i], (struct sockaddr *) &sockaddr, &sockaddr_len);
if (new_socket < 0)
{
if (!s_stop)
syslog(LOG_ERR, "accept error (%m), exiting");
goto end;
}
if (!params->quiet_flag)
{
switch(sockaddr.sin6_family)
{
case AF_INET:
inet_ntop(AF_INET, &((struct sockaddr_in *)&sockaddr)->sin_addr, buffer, sizeof(buffer));
break;
case AF_INET6:
inet_ntop(AF_INET6, &sockaddr.sin6_addr, buffer, sizeof(buffer));
break;
}
/* inet_ntop(sockaddr.sin6_family, &sockaddr.sin6_addr, buffer, sockaddr_len); */
syslog(LOG_INFO, "new connection from %s, socket %d", buffer, new_socket);
}
fill_new_socket(params, new_socket);
}
}
end:
for (i=0; i<s_nb_server_sockets; i++)
close(s_server_sockets[i]);
while (s_last_thread)
{
s_last_thread->stop = 1;
pthread_join(s_last_thread->thread, &thread_ret);
}
closelog();
#ifdef USE_SECCOMP
if (seccomp_ctx)
seccomp_release(seccomp_ctx);
#endif
return 0;
}