initial release of an epoll version

Change-Id: I53bf6621abdbfeb6b5d5f22c2aa632d29c48441b
Signed-off-by: SJ <sj@acts.hu>
This commit is contained in:
SJ 2016-11-06 22:16:03 +01:00
parent 2e5ddbaef5
commit 1c941a6433
5 changed files with 257 additions and 151 deletions

View File

@ -110,7 +110,7 @@ void sanitiseBase64(char *s){
}
inline void pack_4_into_3(char *s, char *s2){
inline static void pack_4_into_3(char *s, char *s2){
int j, n[4], k1, k2;
memset(s2, 0, 3);

View File

@ -376,6 +376,7 @@ struct smtp_session {
char remote_host[INET6_ADDRSTRLEN];
time_t lasttime;
int protocol_state;
int slot;
int fd;
int bad;
int buflen;

View File

@ -645,6 +645,68 @@ void *get_in_addr(struct sockaddr *sa){
}
int make_socket_non_blocking(int fd){
int flags, s;
flags = fcntl(fd, F_GETFL, 0);
if(flags == -1){
return -1;
}
flags |= O_NONBLOCK;
s = fcntl(fd, F_SETFL, flags);
if(s == -1){
return -1;
}
return 0;
}
int create_and_bind(char *listen_addr, int listen_port){
struct addrinfo hints;
struct addrinfo *result, *rp;
char port_string[8];
int rc, fd;
memset(&hints, 0, sizeof (struct addrinfo));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = AI_PASSIVE;
snprintf(port_string, sizeof(port_string)-1, "%d", listen_port);
rc = getaddrinfo(listen_addr, port_string, &hints, &result);
if(rc != 0){
syslog(LOG_PRIORITY, "getaddrinfo for '%s': %s", listen_addr, gai_strerror(rc));
return -1;
}
for(rp = result; rp != NULL; rp = rp->ai_next){
fd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
if(fd == -1)
continue;
rc = bind(fd, rp->ai_addr, rp->ai_addrlen);
if(rc == 0){
break;
}
close(fd);
}
if(rp == NULL){
syslog(LOG_PRIORITY, "cannot bind to port: %s:%d", listen_addr, listen_port);
return -1;
}
freeaddrinfo(result);
return fd;
}
int can_i_write_current_directory(){
int fd;
char filename[SMALLBUFSIZE];

View File

@ -44,6 +44,8 @@ int read_from_stdin(struct session_data *sdata);
void strtolower(char *s);
void *get_in_addr(struct sockaddr *sa);
int make_socket_non_blocking(int fd);
int create_and_bind(char *listen_addr, int listen_port);
int can_i_write_current_directory();

View File

@ -14,7 +14,7 @@
#include <pwd.h>
#include <sys/ioctl.h>
#include <signal.h>
#include <poll.h>
#include <sys/epoll.h>
#include <netinet/in.h>
#include <locale.h>
#include <errno.h>
@ -30,9 +30,9 @@
extern char *optarg;
extern int optind;
struct pollfd *poll_set=NULL;
struct epoll_event event, *events=NULL;
int timeout = 20; // checking for timeout this often [sec]
int numfds = 0;
int num_connections = 0;
int listenerfd = -1;
char *configfile = CONFIG_FILE;
@ -105,7 +105,9 @@ void handle_data(struct smtp_session *session, char *readbuf, int readlen){
}
void init_smtp_session(struct smtp_session *session, int fd_index, int sd){
void init_smtp_session(struct smtp_session *session, int slot, int sd){
session->slot = slot;
session->socket = sd;
session->buflen = 0;
session->protocol_state = SMTP_STATE_INIT;
@ -148,13 +150,12 @@ void p_clean_exit(){
if(listenerfd != -1) close(listenerfd);
for(i=1; i<numfds; i++){
close(poll_set[i].fd);
free_smtp_session(sessions[i]);
for(i=0; i<cfg.max_connections; i++){
if(sessions[i]) free_smtp_session(sessions[i]);
}
if(sessions) free(sessions);
if(poll_set) free(poll_set);
if(events) free(events);
syslog(LOG_PRIORITY, "%s has been terminated", PROGNAME);
@ -172,23 +173,37 @@ void fatal(char *s){
}
void tear_down_client(int n){
int get_session_slot(){
int i;
close(poll_set[n].fd);
poll_set[n].events = 0;
syslog(LOG_PRIORITY, "disconnected from %s", sessions[n]->remote_host);
free_smtp_session(sessions[n]);
sessions[n] = NULL;
for(i=n; i<numfds; i++){
poll_set[i] = poll_set[i+1];
sessions[i] = sessions[i+1];
for(i=0; i<cfg.max_connections; i++){
if(sessions[i] == NULL) return i;
}
numfds--;
return -1;
}
struct smtp_session *get_session_by_socket(int socket){
int i;
for(i=0; i<cfg.max_connections; i++){
if(sessions[i] && sessions[i]->socket == socket) return sessions[i];
}
return NULL;
}
void tear_down_client(int slot){
syslog(LOG_PRIORITY, "disconnected from %s", sessions[slot]->remote_host);
close(sessions[slot]->socket);
free_smtp_session(sessions[slot]);
sessions[slot] = NULL;
num_connections--;
}
@ -196,13 +211,13 @@ void check_for_client_timeout(){
time_t now;
int i;
if(numfds > 1){
if(num_connections > 0){
time(&now);
for(i=1; i<numfds; i++){
if(now - sessions[i]->lasttime >= cfg.smtp_timeout){
for(i=0; i<cfg.max_connections; i++){
if(sessions[i] && now - sessions[i]->lasttime >= cfg.smtp_timeout){
syslog(LOG_PRIORITY, "client %s timeout", sessions[i]->remote_host);
tear_down_client(i);
tear_down_client(sessions[i]->slot);
}
}
}
@ -230,99 +245,52 @@ int is_blocked_by_tcp_wrappers(int sd){
#endif
int create_listener_socket(char *listen_addr, int listen_port){
int rc, sd, yes=1;
char port_string[8];
struct addrinfo hints, *res;
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
snprintf(port_string, sizeof(port_string)-1, "%d", listen_port);
if((rc = getaddrinfo(listen_addr, port_string, &hints, &res)) != 0){
syslog(LOG_PRIORITY, "getaddrinfo for '%s': %s", listen_addr, gai_strerror(rc));
return -1;
}
if((sd = socket(res->ai_family, res->ai_socktype, res->ai_protocol)) == -1){
syslog(LOG_PRIORITY, "socket() error");
return -1;
}
if(setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int)) == -1){
syslog(LOG_PRIORITY, "setsockopt() error");
close(sd);
return -1;
}
if(ioctl(sd, FIONBIO, (char *)&yes) == -1){
syslog(LOG_PRIORITY, "ioctl() failed");
close(sd);
return -1;
}
if(bind(sd, res->ai_addr, res->ai_addrlen) == -1){
syslog(LOG_PRIORITY, "cannot bind to port: %s:%d", listen_addr, listen_port);
close(sd);
return -1;
}
freeaddrinfo(res);
if(listen(sd, cfg.backlog) == -1){
syslog(LOG_PRIORITY, "listen() error");
close(sd);
return -1;
}
return sd;
}
void start_new_session(int socket, struct sockaddr_storage client_address, int fd_index){
char smtp_banner[SMALLBUFSIZE], remote_host[INET6_ADDRSTRLEN];
int start_new_session(int socket){
char smtp_banner[SMALLBUFSIZE];
int slot;
// Uh-oh! We have enough connections to serve already
if(numfds >= cfg.max_connections){
inet_ntop(client_address.ss_family, get_in_addr((struct sockaddr*)&client_address), remote_host, sizeof(remote_host));
syslog(LOG_PRIORITY, "too many connections (%d), cannot accept %s", numfds, remote_host);
if(num_connections >= cfg.max_connections){
syslog(LOG_PRIORITY, "too many connections (%d), cannot accept socket %d", num_connections, socket);
send(socket, SMTP_RESP_421_ERR_ALL_PORTS_ARE_BUSY, strlen(SMTP_RESP_421_ERR_ALL_PORTS_ARE_BUSY), 0);
close(socket);
return;
return -1;
}
#ifdef HAVE_LIBWRAP
if(is_blocked_by_tcp_wrappers(socket) == 1){
close(socket);
return;
return -1;
}
#endif
sessions[numfds] = malloc(sizeof(struct smtp_session));
slot = get_session_slot();
if(sessions[numfds] == NULL){
syslog(LOG_PRIORITY, "malloc error()");
send(socket, SMTP_RESP_421_ERR_TMP, strlen(SMTP_RESP_421_ERR_TMP), 0);
close(socket);
return;
syslog(LOG_PRIORITY, "INFO: found slot: %d", slot);
if(slot >= 0 && sessions[slot] == NULL){
sessions[slot] = malloc(sizeof(struct smtp_session));
if(sessions[slot]){
init_smtp_session(sessions[slot], slot, socket);
snprintf(smtp_banner, sizeof(smtp_banner)-1, SMTP_RESP_220_BANNER, cfg.hostid);
send(socket, smtp_banner, strlen(smtp_banner), 0);
num_connections++;
return 0;
}
else {
syslog(LOG_PRIORITY, "ERROR: malloc() in start_new_session()");
}
}
else {
syslog(LOG_PRIORITY, "ERROR: couldn't find a slot for the connection");
}
send(socket, SMTP_RESP_421_ERR_TMP, strlen(SMTP_RESP_421_ERR_TMP), 0);
close(socket);
init_smtp_session(sessions[numfds], fd_index, socket);
snprintf(smtp_banner, sizeof(smtp_banner)-1, SMTP_RESP_220_BANNER, cfg.hostid);
send(socket, smtp_banner, strlen(smtp_banner), 0);
inet_ntop(client_address.ss_family, get_in_addr((struct sockaddr*)&client_address), sessions[numfds]->remote_host, INET6_ADDRSTRLEN);
syslog(LOG_PRIORITY, "connected from %s", sessions[numfds]->remote_host);
poll_set[numfds].fd = socket;
poll_set[numfds].events = POLLIN|POLLHUP;
numfds++;
return -1;
}
@ -352,12 +320,12 @@ void initialise_configuration(){
int main(int argc, char **argv){
int listenerfd, client_sockfd;
int i, daemonise=0;
int i, n, daemonise=0;
int client_len = sizeof(struct sockaddr_storage);
int readlen;
int bytes_to_read;
struct sockaddr_storage client_address;
char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV];
char readbuf[BIGBUFSIZE];
int efd;
while((i = getopt(argc, argv, "c:dvVh")) > 0){
switch(i){
@ -385,14 +353,28 @@ int main(int argc, char **argv){
initialise_configuration();
listenerfd = create_listener_socket(cfg.listen_addr, cfg.listen_port);
listenerfd = create_and_bind(cfg.listen_addr, cfg.listen_port);
if(listenerfd == -1){
syslog(LOG_PRIORITY, "create_listener_socket() error");
exit(1);
}
if(listen(listenerfd, cfg.backlog) == -1){
fatal("ERROR: listen()");
}
if(drop_privileges(pwd)) fatal(ERR_SETUID);
efd = epoll_create1(0);
if(efd == -1){
fatal("ERROR: epoll_create()");
}
event.data.fd = listenerfd;
event.events = EPOLLIN | EPOLLET;
if(epoll_ctl(efd, EPOLL_CTL_ADD, listenerfd, &event) == -1){
fatal("ERROR: epoll_ctl() on efd");
}
set_signal_handler(SIGINT, p_clean_exit);
set_signal_handler(SIGTERM, p_clean_exit);
set_signal_handler(SIGALRM, check_for_client_timeout);
@ -403,13 +385,9 @@ int main(int argc, char **argv){
// calloc() initialitizes the allocated memory
sessions = calloc(cfg.max_connections, sizeof(struct smtp_session));
poll_set = calloc(cfg.max_connections, sizeof(struct pollfd));
events = calloc(cfg.max_connections, sizeof(struct epoll_event));
if(!sessions || !poll_set) fatal("calloc() error");
poll_set[0].fd = listenerfd;
poll_set[0].events = POLLIN;
numfds = 1;
if(!sessions || !events) fatal("ERROR: calloc()");
SSL_library_init();
SSL_load_error_strings();
@ -423,55 +401,118 @@ int main(int argc, char **argv){
#endif
for(;;){
int fd_index;
n = epoll_wait(efd, events, cfg.max_connections, -1);
for(i=0; i<n; i++){
poll(poll_set, numfds, -1);
if((events[i].events & EPOLLERR) || (events[i].events & EPOLLHUP) || (!(events[i].events & EPOLLIN))){
syslog(LOG_PRIORITY, "ERROR: epoll error");
close(events[i].data.fd);
// we have to tear_down_client as well if not the listening socket?
continue;
}
for(fd_index = 0; fd_index < numfds; fd_index++){
if(poll_set[fd_index].revents & POLLIN){
// We have 1 or more incoming connections to process
// process new connection
else if(listenerfd == events[i].data.fd){
while(1){
if(poll_set[fd_index].fd == listenerfd){
client_sockfd = accept(listenerfd, (struct sockaddr *)&client_address, (socklen_t *)&client_len);
start_new_session(client_sockfd, client_address, fd_index);
if(client_sockfd == -1){
if((errno == EAGAIN) || (errno == EWOULDBLOCK)){
// We have processed all incoming connections
break;
}
else {
syslog(LOG_PRIORITY, "ERROR: accept()");
break;
}
}
if(getnameinfo((struct sockaddr *)&client_address, client_len, hbuf, sizeof(hbuf), sbuf, sizeof(sbuf), NI_NUMERICHOST | NI_NUMERICSERV) == 0){
syslog(LOG_PRIORITY, "connected from %s:%s on descriptor %d", hbuf, sbuf, client_sockfd);
}
if(make_socket_non_blocking(client_sockfd) == -1){
syslog(LOG_PRIORITY, "ERROR: cannot make the socket non blocking");
break;
}
event.data.fd = client_sockfd;
event.events = EPOLLIN | EPOLLET;
if(epoll_ctl(efd, EPOLL_CTL_ADD, client_sockfd, &event) == -1){
syslog(LOG_PRIORITY, "ERROR: epoll_ctl() on client_sockfd");
break;
}
start_new_session(client_sockfd);
}
// handle data from an existing connection
continue;
}
else {
ioctl(poll_set[fd_index].fd, FIONREAD, &bytes_to_read);
if(cfg.verbosity >= _LOG_DEBUG) syslog(LOG_PRIORITY, "got %d bytes to read", bytes_to_read);
// handle data from an existing connection
if(bytes_to_read == 0){
tear_down_client(fd_index);
else {
int done = 0;
ssize_t count;
// should the following work here as well?
// ioctl(events[i].data.fd, FIONREAD, &bytes_to_read);
session = get_session_by_socket(events[i].data.fd);
if(session == NULL){
syslog(LOG_PRIORITY, "ERROR: cannot find session for this socket: %d", events[i].data.fd);
close(events[i].data.fd);
continue;
}
time(&(session->lasttime));
while(1){
memset(readbuf, 0, sizeof(readbuf));
if(session->use_ssl == 1)
count = SSL_read(session->ssl, (char*)&readbuf[0], sizeof(readbuf)-1);
else
count = read(events[i].data.fd, (char*)&readbuf[0], sizeof(readbuf)-1);
if(cfg.verbosity >= _LOG_DEBUG) syslog(LOG_PRIORITY, "got %ld bytes to read", count);
if(count == -1){
/* If errno == EAGAIN, that means we have read all data. So go back to the main loop. */
if(errno != EAGAIN){
syslog(LOG_PRIORITY, "read");
done = 1;
}
break;
}
else {
session = sessions[fd_index];
time(&(session->lasttime));
// readbuf must be large enough to hold 'bytes_to_read' data
// I think there shouldn't be more than MTU size data to be
// read from the socket at a time
memset(readbuf, 0, sizeof(readbuf));
if(session->use_ssl == 1)
readlen = SSL_read(session->ssl, (char*)&readbuf[0], sizeof(readbuf)-1);
else
readlen = recv(poll_set[fd_index].fd, &readbuf[0], sizeof(readbuf)-1, 0);
if(readlen < 1) break;
readbuf[readlen] = '\0'; // we need either this or memset(readbuf, ...) above
handle_data(session, &readbuf[0], readlen);
if(session->protocol_state == SMTP_STATE_BDAT && session->bad == 1) tear_down_client(fd_index);
else if(count == 0){
/* End of file. The remote has closed the connection. */
done = 1;
break;
}
handle_data(session, &readbuf[0], count);
if(session->protocol_state == SMTP_STATE_BDAT && session->bad == 1){
tear_down_client(session->slot);
done = 0; // to prevent the repeated tear down of connection
break;
}
}
if(done){
printf("Closed connection on descriptor %d\n", events[i].data.fd);
/* Closing the descriptor will make epoll remove it from the set of descriptors which are monitored. */
//close(events[i].data.fd);
tear_down_client(session->slot);
}
}
}
}