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Use checked versions of FD_* macros. Closes #2202
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@bonsaiviking
bonsaiviking committed Jan 7, 2021
1 parent 3ecec3f commit 28bfe0d
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Showing 5 changed files with 53 additions and 50 deletions.
3 changes: 3 additions & 0 deletions CHANGELOG
View file
@@ -1,5 +1,8 @@
#Nmap Changelog ($Id$); -*-text-*-

o [Ncat][GH#2202] Use safety-checked versions of FD_* macros to abort early if
number of connections exceeds FD_SETSIZE. [Pavel Zhukov]

o Nmap will now output a list of port numbers for each "ignored" state in the
"extrareasons" element in XML output. The "All X ports" and "Not shown:" lines
in normal output have been changed slightly to provide more detail. [Daniel Miller]
Expand Down
2 changes: 1 addition & 1 deletion ncat/ncat_core.c
View file
Expand Up @@ -431,7 +431,7 @@ int ncat_broadcast(fd_set *fds, const fd_list_t *fdlist, const char *msg, size_t

ret = 0;
for (i = 0; i <= fdlist->fdmax; i++) {
if (!FD_ISSET(i, fds))
if (!checked_fd_isset(i, fds))
continue;

fdn = get_fdinfo(fdlist, i);
Expand Down
78 changes: 39 additions & 39 deletions ncat/ncat_listen.c
View file
Expand Up @@ -244,10 +244,10 @@ static int ncat_listen_stream(int proto)
unblock_socket(listen_socket[num_sockets]);

/* setup select sets and max fd */
FD_SET(listen_socket[num_sockets], &master_readfds);
checked_fd_set(listen_socket[num_sockets], &master_readfds);
add_fd(&client_fdlist, listen_socket[num_sockets]);

FD_SET(listen_socket[num_sockets], &listen_fds);
checked_fd_set(listen_socket[num_sockets], &listen_fds);

num_sockets++;
}
Expand Down Expand Up @@ -296,35 +296,35 @@ static int ncat_listen_stream(int proto)
struct fdinfo *fdi = &client_fdlist.fds[i];
int cfd = fdi->fd;
/* Loop through descriptors until there's something to read */
if (!FD_ISSET(cfd, &readfds) && !FD_ISSET(cfd, &writefds))
if (!checked_fd_isset(cfd, &readfds) && !checked_fd_isset(cfd, &writefds))
continue;

if (o.debug > 1)
logdebug("fd %d is ready\n", cfd);

#ifdef HAVE_OPENSSL
/* Is this an ssl socket pending a handshake? If so handle it. */
if (o.ssl && FD_ISSET(cfd, &sslpending_fds)) {
FD_CLR(cfd, &master_readfds);
FD_CLR(cfd, &master_writefds);
if (o.ssl && checked_fd_isset(cfd, &sslpending_fds)) {
checked_fd_clr(cfd, &master_readfds);
checked_fd_clr(cfd, &master_writefds);
switch (ssl_handshake(fdi)) {
case NCAT_SSL_HANDSHAKE_COMPLETED:
/* Clear from sslpending_fds once ssl is established */
FD_CLR(cfd, &sslpending_fds);
checked_fd_clr(cfd, &sslpending_fds);
post_handle_connection(*fdi);
break;
case NCAT_SSL_HANDSHAKE_PENDING_WRITE:
FD_SET(cfd, &master_writefds);
checked_fd_set(cfd, &master_writefds);
break;
case NCAT_SSL_HANDSHAKE_PENDING_READ:
FD_SET(cfd, &master_readfds);
checked_fd_set(cfd, &master_readfds);
break;
case NCAT_SSL_HANDSHAKE_FAILED:
default:
SSL_free(fdi->ssl);
Close(fdi->fd);
FD_CLR(cfd, &sslpending_fds);
FD_CLR(cfd, &master_readfds);
checked_fd_clr(cfd, &sslpending_fds);
checked_fd_clr(cfd, &master_readfds);
rm_fd(&client_fdlist, cfd);
/* Since we removed this one, start loop over at the beginning.
* Wastes a little time, but ensures correctness.
Expand All @@ -339,7 +339,7 @@ static int ncat_listen_stream(int proto)
}
} else
#endif
if (FD_ISSET(cfd, &listen_fds)) {
if (checked_fd_isset(cfd, &listen_fds)) {
/* we have a new connection request */
handle_connection(cfd);
} else if (cfd == STDIN_FILENO) {
Expand Down Expand Up @@ -424,7 +424,7 @@ static void handle_connection(int socket_accept)
int i;
for (i = 0; i < num_listenaddrs; i++) {
Close(listen_socket[i]);
FD_CLR(listen_socket[i], &master_readfds);
checked_fd_clr(listen_socket[i], &master_readfds);
rm_fd(&client_fdlist, listen_socket[i]);
}
}
Expand Down Expand Up @@ -468,9 +468,9 @@ static void handle_connection(int socket_accept)
#ifdef HAVE_OPENSSL
if (o.ssl) {
/* Add the socket to the necessary descriptor lists. */
FD_SET(s.fd, &sslpending_fds);
FD_SET(s.fd, &master_readfds);
FD_SET(s.fd, &master_writefds);
checked_fd_set(s.fd, &sslpending_fds);
checked_fd_set(s.fd, &master_readfds);
checked_fd_set(s.fd, &master_writefds);
/* Add it to our list of fds too for maintaining maxfd. */
if (add_fdinfo(&client_fdlist, &s) < 0)
bye("add_fdinfo() failed.");
Expand Down Expand Up @@ -503,10 +503,10 @@ static void post_handle_connection(struct fdinfo sinfo)
} else {
/* Now that a client is connected, pay attention to stdin. */
if (!stdin_eof)
FD_SET(STDIN_FILENO, &master_readfds);
checked_fd_set(STDIN_FILENO, &master_readfds);
if (!o.sendonly) {
/* add to our lists */
FD_SET(sinfo.fd, &master_readfds);
checked_fd_set(sinfo.fd, &master_readfds);
/* add it to our list of fds for maintaining maxfd */
#ifdef HAVE_OPENSSL
/* Don't add it twice (see handle_connection above) */
Expand All @@ -518,7 +518,7 @@ static void post_handle_connection(struct fdinfo sinfo)
}
#endif
}
FD_SET(sinfo.fd, &master_broadcastfds);
checked_fd_set(sinfo.fd, &master_broadcastfds);
if (add_fdinfo(&broadcast_fdlist, &sinfo) < 0)
bye("add_fdinfo() failed.");

Expand All @@ -543,7 +543,7 @@ int read_stdin(void)
logdebug("EOF on stdin\n");

/* Don't close the file because that allows a socket to be fd 0. */
FD_CLR(STDIN_FILENO, &master_readfds);
checked_fd_clr(STDIN_FILENO, &master_readfds);
/* Buf mark that we've seen EOF so it doesn't get re-added to the
select list. */
stdin_eof = 1;
Expand Down Expand Up @@ -596,14 +596,14 @@ int read_socket(int recv_fd)
}
#endif
close(recv_fd);
FD_CLR(recv_fd, &master_readfds);
checked_fd_clr(recv_fd, &master_readfds);
rm_fd(&client_fdlist, recv_fd);
FD_CLR(recv_fd, &master_broadcastfds);
checked_fd_clr(recv_fd, &master_broadcastfds);
rm_fd(&broadcast_fdlist, recv_fd);

conn_inc--;
if (get_conn_count() == 0)
FD_CLR(STDIN_FILENO, &master_readfds);
checked_fd_clr(STDIN_FILENO, &master_readfds);

return n;
}
Expand Down Expand Up @@ -693,7 +693,7 @@ static int ncat_listen_dgram(int proto)
logdebug("do_listen(\"%s\"): %s\n", inet_ntop_ez(&listenaddrs[i].storage, sizeof(listenaddrs[i].storage)), socket_strerror(socket_errno()));
continue;
}
FD_SET(sockfd[num_sockets].fd, &listen_fds);
checked_fd_set(sockfd[num_sockets].fd, &listen_fds);
add_fd(&listen_fdlist, sockfd[num_sockets].fd);
sockfd[num_sockets].addr = listenaddrs[i];
num_sockets++;
Expand All @@ -713,14 +713,14 @@ static int ncat_listen_dgram(int proto)

if (fdn != -1) {
/*remove socket descriptor which is burnt */
FD_CLR(sockfd[fdn].fd, &listen_fds);
checked_fd_clr(sockfd[fdn].fd, &listen_fds);
rm_fd(&listen_fdlist, sockfd[fdn].fd);

/* Rebuild the udp socket which got burnt */
sockfd[fdn].fd = do_listen(SOCK_DGRAM, proto, &sockfd[fdn].addr);
if (sockfd[fdn].fd == -1)
bye("do_listen: %s", socket_strerror(socket_errno()));
FD_SET(sockfd[fdn].fd, &listen_fds);
checked_fd_set(sockfd[fdn].fd, &listen_fds);
add_fd(&listen_fdlist, sockfd[fdn].fd);

}
Expand Down Expand Up @@ -758,7 +758,7 @@ static int ncat_listen_dgram(int proto)
*/
for (i = 0; i <= listen_fdlist.fdmax && fds_ready > 0; i++) {
/* Loop through descriptors until there is something ready */
if (!FD_ISSET(i, &fds))
if (!checked_fd_isset(i, &fds))
continue;

/* Check each listening socket */
Expand Down Expand Up @@ -856,8 +856,8 @@ static int ncat_listen_dgram(int proto)
continue;
}

FD_SET(socket_n, &read_fds);
FD_SET(STDIN_FILENO, &read_fds);
checked_fd_set(socket_n, &read_fds);
checked_fd_set(STDIN_FILENO, &read_fds);
fdmax = socket_n;

/* stdin -> socket and socket -> stdout */
Expand All @@ -877,15 +877,15 @@ static int ncat_listen_dgram(int proto)
if (fds_ready == 0)
bye("Idle timeout expired (%d ms).", o.idletimeout);

if (FD_ISSET(STDIN_FILENO, &fds)) {
if (checked_fd_isset(STDIN_FILENO, &fds)) {
nbytes = Read(STDIN_FILENO, buf, sizeof(buf));
if (nbytes <= 0) {
if (nbytes < 0 && o.verbose) {
logdebug("Error reading from stdin: %s\n", strerror(errno));
} else if (nbytes == 0 && o.debug) {
logdebug("EOF on stdin\n");
}
FD_CLR(STDIN_FILENO, &read_fds);
checked_fd_clr(STDIN_FILENO, &read_fds);
if (nbytes < 0)
return 1;
continue;
Expand All @@ -909,7 +909,7 @@ static int ncat_listen_dgram(int proto)
tempbuf = NULL;
}
}
if (FD_ISSET(socket_n, &fds)) {
if (checked_fd_isset(socket_n, &fds)) {
nbytes = recv(socket_n, buf, sizeof(buf), 0);
if (nbytes < 0) {
loguser("%s.\n", socket_strerror(socket_errno()));
Expand Down Expand Up @@ -993,7 +993,7 @@ static void read_and_broadcast(int recv_fd)

/* Don't close the file because that allows a socket to be
fd 0. */
FD_CLR(recv_fd, &master_readfds);
checked_fd_clr(recv_fd, &master_readfds);
/* But mark that we've seen EOF so it doesn't get re-added to
the select list. */
stdin_eof = 1;
Expand All @@ -1020,14 +1020,14 @@ static void read_and_broadcast(int recv_fd)
}
#endif
close(recv_fd);
FD_CLR(recv_fd, &master_readfds);
checked_fd_clr(recv_fd, &master_readfds);
rm_fd(&client_fdlist, recv_fd);
FD_CLR(recv_fd, &master_broadcastfds);
checked_fd_clr(recv_fd, &master_broadcastfds);
rm_fd(&broadcast_fdlist, recv_fd);

conn_inc--;
if (conn_inc == 0)
FD_CLR(STDIN_FILENO, &master_readfds);
checked_fd_clr(STDIN_FILENO, &master_readfds);

if (o.chat)
chat_announce_disconnect(recv_fd);
Expand Down Expand Up @@ -1058,7 +1058,7 @@ static void read_and_broadcast(int recv_fd)

/* Send to everyone except the one who sent this message. */
broadcastfds = master_broadcastfds;
FD_CLR(recv_fd, &broadcastfds);
checked_fd_clr(recv_fd, &broadcastfds);
ncat_broadcast(&broadcastfds, &broadcast_fdlist, outbuf, n);

free(chatbuf);
Expand All @@ -1073,7 +1073,7 @@ static void shutdown_sockets(int how)
int i;

for (i = 0; i <= broadcast_fdlist.fdmax; i++) {
if (!FD_ISSET(i, &master_broadcastfds))
if (!checked_fd_isset(i, &master_broadcastfds))
continue;

fdn = get_fdinfo(&broadcast_fdlist, i);
Expand All @@ -1098,7 +1098,7 @@ static int chat_announce_connect(int fd, const union sockaddr_u *su)
union sockaddr_u tsu;
socklen_t len = sizeof(tsu.storage);

if (i == fd || !FD_ISSET(i, &master_broadcastfds))
if (i == fd || !checked_fd_isset(i, &master_broadcastfds))
continue;

if (getpeername(i, &tsu.sockaddr, &len) == -1)
Expand Down
8 changes: 4 additions & 4 deletions ncat/ncat_posix.c
View file
Expand Up @@ -205,8 +205,8 @@ void netexec(struct fdinfo *info, char *cmdexec)
int r, n_r;

FD_ZERO(&fds);
FD_SET(info->fd, &fds);
FD_SET(child_stdout[0], &fds);
checked_fd_set(info->fd, &fds);
checked_fd_set(child_stdout[0], &fds);

r = fselect(maxfd + 1, &fds, NULL, NULL, NULL);
if (r == -1) {
Expand All @@ -215,7 +215,7 @@ void netexec(struct fdinfo *info, char *cmdexec)
else
break;
}
if (FD_ISSET(info->fd, &fds)) {
if (checked_fd_isset(info->fd, &fds)) {
int pending;

do {
Expand All @@ -225,7 +225,7 @@ void netexec(struct fdinfo *info, char *cmdexec)
write_loop(child_stdin[1], buf, n_r);
} while (pending);
}
if (FD_ISSET(child_stdout[0], &fds)) {
if (checked_fd_isset(child_stdout[0], &fds)) {
char *crlf = NULL, *wbuf;
n_r = read(child_stdout[0], buf, sizeof(buf));
if (n_r <= 0)
Expand Down
12 changes: 6 additions & 6 deletions ncat/ncat_proxy.c
View file
Expand Up @@ -166,7 +166,7 @@ int ncat_http_server(void)
unblock_socket(listen_socket[num_sockets]);

/* setup select sets and max fd */
FD_SET(listen_socket[num_sockets], &listen_fds);
checked_fd_set(listen_socket[num_sockets], &listen_fds);
add_fd(&listen_fdlist, listen_socket[num_sockets]);

num_sockets++;
Expand Down Expand Up @@ -199,7 +199,7 @@ int ncat_http_server(void)

for (i = 0; i <= listen_fdlist.fdmax && fds_ready > 0; i++) {
/* Loop through descriptors until there is something ready */
if (!FD_ISSET(i, &read_fds))
if (!checked_fd_isset(i, &read_fds))
continue;

/* Check each listening socket */
Expand Down Expand Up @@ -457,8 +457,8 @@ static int handle_connect(struct socket_buffer *client_sock,

maxfd = client_sock->fdn.fd < s ? s : client_sock->fdn.fd;
FD_ZERO(&m);
FD_SET(client_sock->fdn.fd, &m);
FD_SET(s, &m);
checked_fd_set(client_sock->fdn.fd, &m);
checked_fd_set(s, &m);

errno = 0;

Expand All @@ -472,7 +472,7 @@ static int handle_connect(struct socket_buffer *client_sock,

zmem(buf, sizeof(buf));

if (FD_ISSET(client_sock->fdn.fd, &r)) {
if (checked_fd_isset(client_sock->fdn.fd, &r)) {
do {
do {
len = fdinfo_recv(&client_sock->fdn, buf, sizeof(buf));
Expand All @@ -488,7 +488,7 @@ static int handle_connect(struct socket_buffer *client_sock,
} while (fdinfo_pending(&client_sock->fdn));
}

if (FD_ISSET(s, &r)) {
if (checked_fd_isset(s, &r)) {
do {
len = recv(s, buf, sizeof(buf), 0);
} while (len == -1 && socket_errno() == EINTR);
Expand Down

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