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[tor-commits] [tor/master] Validate the open file limit when creating a socket
commit 699acd8d54bd685b135d3a8e758d05dd0802b820
Author: David Goulet <dgoulet@xxxxxxxxx>
Date: Wed Jun 3 13:56:01 2015 -0400
Validate the open file limit when creating a socket
Fixes #16288
Signed-off-by: David Goulet <dgoulet@xxxxxxxxx>
---
changes/bug16288 | 6 ++++++
src/common/compat.c | 47 ++++++++++++++++++++++++++++++++++++++++-------
src/common/compat.h | 4 ++--
src/or/connection.c | 39 +++++++++++++++++++++------------------
4 files changed, 69 insertions(+), 27 deletions(-)
diff --git a/changes/bug16288 b/changes/bug16288
new file mode 100644
index 0000000..7ddf615
--- /dev/null
+++ b/changes/bug16288
@@ -0,0 +1,6 @@
+ o Major bugfixes (open file limit):
+ - The max open file limit wasn't checked before calling
+ tor_accept_socket_nonblocking() which made tor go beyond the open
+ file limit set previously. With this fix, before opening a new socket,
+ tor validates the open file limit just before and if the max has been
+ reached, return EMFILE.; Fixes #16288; bugfix on tor-0.1.1.1-alpha~74.
diff --git a/src/common/compat.c b/src/common/compat.c
index 8da7ef3..ac47321 100644
--- a/src/common/compat.c
+++ b/src/common/compat.c
@@ -131,6 +131,11 @@
#include "strlcat.c"
#endif
+/* When set_max_file_descriptors() is called, update this with the max file
+ * descriptor value so we can use it to check the limit when opening a new
+ * socket. Default value is what Debian sets as the default hard limit. */
+static int max_sockets = 1024;
+
/** As open(path, flags, mode), but return an fd with the close-on-exec mode
* set. */
int
@@ -1187,6 +1192,18 @@ tor_open_socket_with_extensions(int domain, int type, int protocol,
int cloexec, int nonblock)
{
tor_socket_t s;
+
+ /* We are about to create a new file descriptor so make sure we have
+ * enough of them. */
+ if (get_n_open_sockets() >= max_sockets - 1) {
+#ifdef _WIN32
+ WSASetLastError(WSAEMFILE);
+#else
+ errno = EMFILE;
+#endif
+ return TOR_INVALID_SOCKET;
+ }
+
#if defined(SOCK_CLOEXEC) && defined(SOCK_NONBLOCK)
int ext_flags = (cloexec ? SOCK_CLOEXEC : 0) |
(nonblock ? SOCK_NONBLOCK : 0);
@@ -1258,6 +1275,18 @@ tor_accept_socket_with_extensions(tor_socket_t sockfd, struct sockaddr *addr,
socklen_t *len, int cloexec, int nonblock)
{
tor_socket_t s;
+
+ /* We are about to create a new file descriptor so make sure we have
+ * enough of them. */
+ if (get_n_open_sockets() >= max_sockets - 1) {
+#ifdef _WIN32
+ WSASetLastError(WSAEMFILE);
+#else
+ errno = EMFILE;
+#endif
+ return TOR_INVALID_SOCKET;
+ }
+
#if defined(HAVE_ACCEPT4) && defined(SOCK_CLOEXEC) && defined(SOCK_NONBLOCK)
int ext_flags = (cloexec ? SOCK_CLOEXEC : 0) |
(nonblock ? SOCK_NONBLOCK : 0);
@@ -1553,6 +1582,12 @@ tor_ersatz_socketpair(int family, int type, int protocol, tor_socket_t fd[2])
int
set_max_file_descriptors(rlim_t limit, int *max_out)
{
+ if (limit < ULIMIT_BUFFER) {
+ log_warn(LD_CONFIG,
+ "ConnLimit must be at least %d. Failing.", ULIMIT_BUFFER);
+ return -1;
+ }
+
/* Define some maximum connections values for systems where we cannot
* automatically determine a limit. Re Cygwin, see
* http://archives.seul.org/or/talk/Aug-2006/msg00210.html
@@ -1592,7 +1627,7 @@ set_max_file_descriptors(rlim_t limit, int *max_out)
limit = rlim.rlim_max;
if (limit > INT_MAX)
limit = INT_MAX;
- *max_out = (int)limit - ULIMIT_BUFFER;
+ *max_out = max_sockets = (int)limit - ULIMIT_BUFFER;
return 0;
}
if (rlim.rlim_max < limit) {
@@ -1606,6 +1641,9 @@ set_max_file_descriptors(rlim_t limit, int *max_out)
log_info(LD_NET,"Raising max file descriptors from %lu to %lu.",
(unsigned long)rlim.rlim_cur, (unsigned long)rlim.rlim_max);
}
+ /* Set the current limit value so if the attempt to set the limit to the
+ * max fails at least we'll have a valid value of maximum sockets. */
+ max_sockets = rlim.rlim_cur - ULIMIT_BUFFER;
rlim.rlim_cur = rlim.rlim_max;
if (setrlimit(RLIMIT_NOFILE, &rlim) != 0) {
@@ -1639,15 +1677,10 @@ set_max_file_descriptors(rlim_t limit, int *max_out)
limit = rlim.rlim_cur;
#endif /* HAVE_GETRLIMIT */
- if (limit < ULIMIT_BUFFER) {
- log_warn(LD_CONFIG,
- "ConnLimit must be at least %d. Failing.", ULIMIT_BUFFER);
- return -1;
- }
if (limit > INT_MAX)
limit = INT_MAX;
tor_assert(max_out);
- *max_out = (int)limit - ULIMIT_BUFFER;
+ *max_out = max_sockets = (int)limit - ULIMIT_BUFFER;
return 0;
}
diff --git a/src/common/compat.h b/src/common/compat.h
index 5189b7e..acf5ffd 100644
--- a/src/common/compat.h
+++ b/src/common/compat.h
@@ -580,7 +580,7 @@ int network_init(void);
#define ERRNO_IS_ACCEPT_EAGAIN(e) ERRNO_IS_EAGAIN(e)
/** Return true if e is EMFILE or another error indicating that a call to
* accept() has failed because we're out of fds or something. */
-#define ERRNO_IS_ACCEPT_RESOURCE_LIMIT(e) \
+#define ERRNO_IS_RESOURCE_LIMIT(e) \
((e) == WSAEMFILE || (e) == WSAENOBUFS)
/** Return true if e is EADDRINUSE or the local equivalent. */
#define ERRNO_IS_EADDRINUSE(e) ((e) == WSAEADDRINUSE)
@@ -598,7 +598,7 @@ const char *tor_socket_strerror(int e);
#define ERRNO_IS_CONN_EINPROGRESS(e) ((e) == EINPROGRESS || 0)
#define ERRNO_IS_ACCEPT_EAGAIN(e) \
(ERRNO_IS_EAGAIN(e) || (e) == ECONNABORTED)
-#define ERRNO_IS_ACCEPT_RESOURCE_LIMIT(e) \
+#define ERRNO_IS_RESOURCE_LIMIT(e) \
((e) == EMFILE || (e) == ENFILE || (e) == ENOBUFS || (e) == ENOMEM)
#define ERRNO_IS_EADDRINUSE(e) (((e) == EADDRINUSE) || 0)
#define tor_socket_errno(sock) (errno)
diff --git a/src/or/connection.c b/src/or/connection.c
index bd17629..7089292 100644
--- a/src/or/connection.c
+++ b/src/or/connection.c
@@ -1093,11 +1093,6 @@ connection_listener_new(const struct sockaddr *listensockaddr,
static int global_next_session_group = SESSION_GROUP_FIRST_AUTO;
tor_addr_t addr;
- if (get_n_open_sockets() >= options->ConnLimit_-1) {
- warn_too_many_conns();
- return NULL;
- }
-
if (listensockaddr->sa_family == AF_INET ||
listensockaddr->sa_family == AF_INET6) {
int is_stream = (type != CONN_TYPE_AP_DNS_LISTENER);
@@ -1113,8 +1108,13 @@ connection_listener_new(const struct sockaddr *listensockaddr,
is_stream ? SOCK_STREAM : SOCK_DGRAM,
is_stream ? IPPROTO_TCP: IPPROTO_UDP);
if (!SOCKET_OK(s)) {
- log_warn(LD_NET, "Socket creation failed: %s",
- tor_socket_strerror(tor_socket_errno(-1)));
+ int e = tor_socket_errno(s);
+ if (ERRNO_IS_RESOURCE_LIMIT(e)) {
+ warn_too_many_conns();
+ } else {
+ log_warn(LD_NET, "Socket creation failed: %s",
+ tor_socket_strerror(e));
+ }
goto err;
}
@@ -1222,7 +1222,12 @@ connection_listener_new(const struct sockaddr *listensockaddr,
s = tor_open_socket_nonblocking(AF_UNIX, SOCK_STREAM, 0);
if (! SOCKET_OK(s)) {
- log_warn(LD_NET,"Socket creation failed: %s.", strerror(errno));
+ int e = tor_socket_errno(s);
+ if (ERRNO_IS_RESOURCE_LIMIT(e)) {
+ warn_too_many_conns();
+ } else {
+ log_warn(LD_NET,"Socket creation failed: %s.", strerror(e));
+ }
goto err;
}
@@ -1430,7 +1435,7 @@ connection_handle_listener_read(connection_t *conn, int new_type)
int e = tor_socket_errno(conn->s);
if (ERRNO_IS_ACCEPT_EAGAIN(e)) {
return 0; /* he hung up before we could accept(). that's fine. */
- } else if (ERRNO_IS_ACCEPT_RESOURCE_LIMIT(e)) {
+ } else if (ERRNO_IS_RESOURCE_LIMIT(e)) {
warn_too_many_conns();
return 0;
}
@@ -1624,12 +1629,6 @@ connection_connect_sockaddr(connection_t *conn,
tor_assert(sa);
tor_assert(socket_error);
- if (get_n_open_sockets() >= get_options()->ConnLimit_-1) {
- warn_too_many_conns();
- *socket_error = SOCK_ERRNO(ENOBUFS);
- return -1;
- }
-
if (get_options()->DisableNetwork) {
/* We should never even try to connect anyplace if DisableNetwork is set.
* Warn if we do, and refuse to make the connection. */
@@ -1647,9 +1646,13 @@ connection_connect_sockaddr(connection_t *conn,
s = tor_open_socket_nonblocking(protocol_family, SOCK_STREAM, proto);
if (! SOCKET_OK(s)) {
- *socket_error = tor_socket_errno(-1);
- log_warn(LD_NET,"Error creating network socket: %s",
- tor_socket_strerror(*socket_error));
+ *socket_error = tor_socket_errno(s);
+ if (ERRNO_IS_RESOURCE_LIMIT(*socket_error)) {
+ warn_too_many_conns();
+ } else {
+ log_warn(LD_NET,"Error creating network socket: %s",
+ tor_socket_strerror(*socket_error));
+ }
return -1;
}
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