[tor-commits] [torsocks/master] Support the various epoll routines when invoked via syscall().

[dgoulet at torproject.org]

commit 5e7d572a52a8fe6774d3b5d3177eb12461a234b7
Author: Yawning Angel <yawning at schwanenlied.me>
Date:   Tue Apr 7 11:10:47 2015 +0000

    Support the various epoll routines when invoked via syscall().
    
    Signed-off-by: Yawning Angel <yawning at schwanenlied.me>
---
 src/common/compat.h |   26 +++++++++++++++++
 src/lib/syscall.c   |   80 +++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 106 insertions(+)

diff --git a/src/common/compat.h b/src/common/compat.h
index b4bef9a..8c3be78 100644
--- a/src/common/compat.h
+++ b/src/common/compat.h
@@ -111,6 +111,32 @@ void tsocks_mutex_unlock(tsocks_mutex_t *m);
 #define TSOCKS_NR_FUTEX     __NR_futex
 #define TSOCKS_NR_ACCEPT4   __NR_accept4
 
+/*
+ * Despite glibc providing wrappers for these calls for a long time
+ * (as in "even Debian squeeze has all the wrappers"), libuv decided to
+ * use syscall() to invoke them instead.
+ */
+
+#include <sys/epoll.h>
+
+#ifndef __NR_epoll_create1
+#define __NR_epoll_create1 -128
+#endif
+#ifndef __NR_epoll_wait
+#define __NR_epoll_wait -129
+#endif
+#ifndef __NR_epoll_pwait
+#define __NR_epoll_pwait -130
+#endif
+#ifndef __NR_epoll_ctl
+#define __NR_epoll_ctl -131
+#endif
+
+#define TSOCKS_NR_EPOLL_CREATE1 __NR_epoll_create1
+#define TSOCKS_NR_EPOLL_WAIT    __NR_epoll_wait
+#define TSOCKS_NR_EPOLL_PWAIT   __NR_epoll_pwait
+#define TSOCKS_NR_EPOLL_CTL     __NR_epoll_ctl
+
 #endif /* __linux__ */
 
 #if (defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__darwin__) || defined(__NetBSD__))
diff --git a/src/lib/syscall.c b/src/lib/syscall.c
index 5dad3ce..c6585a8 100644
--- a/src/lib/syscall.c
+++ b/src/lib/syscall.c
@@ -230,6 +230,74 @@ static LIBC_SYSCALL_RET_TYPE handle_accept4(va_list args)
 
 	return tsocks_accept4(sockfd, addr, &addrlen, flags);
 }
+
+/*
+ * Handle epoll_create1(2) syscall.
+ */
+static LIBC_SYSCALL_RET_TYPE handle_epoll_create1(va_list args)
+{
+	int flags;
+
+	flags = va_arg(args, __typeof__(flags));
+
+	return epoll_create1(flags);
+}
+
+/*
+ * Handle epoll_wait(2) syscall.
+ */
+static LIBC_SYSCALL_RET_TYPE handle_epoll_wait(va_list args)
+{
+	int epfd;
+	struct epoll_event *events;
+	int maxevents;
+	int timeout;
+
+	epfd = va_arg(args, __typeof__(epfd));
+	events = va_arg(args, __typeof__(events));
+	maxevents = va_arg(args, __typeof__(maxevents));
+	timeout = va_arg(args, __typeof__(maxevents));
+
+	return epoll_wait(epfd, events, maxevents, timeout);
+}
+
+/*
+ * Handle epoll_pwait(2) syscall.
+ */
+static LIBC_SYSCALL_RET_TYPE handle_epoll_pwait(va_list args)
+{
+	int epfd;
+	struct epoll_event *events;
+	int maxevents;
+	int timeout;
+	const sigset_t *sigmask;
+
+	epfd = va_arg(args, __typeof__(epfd));
+	events = va_arg(args, __typeof__(events));
+	maxevents = va_arg(args, __typeof__(maxevents));
+	timeout = va_arg(args, __typeof__(maxevents));
+	sigmask = va_arg(args, __typeof__(sigmask));
+
+	return epoll_pwait(epfd, events, maxevents, timeout, sigmask);
+}
+
+/*
+ * Handle epoll_ctl(2) syscall.
+ */
+static LIBC_SYSCALL_RET_TYPE handle_epoll_ctl(va_list args)
+{
+	int epfd;
+	int op;
+	int fd;
+	struct epoll_event *event;
+
+	epfd = va_arg(args, __typeof__(epfd));
+	op = va_arg(args, __typeof__(op));
+	fd = va_arg(args, __typeof__(fd));
+	event = va_arg(args, __typeof__(event));
+
+	return epoll_ctl(epfd, op, fd, event);
+}
 #endif /* __linux__ */
 
 /*
@@ -309,6 +377,18 @@ LIBC_SYSCALL_RET_TYPE tsocks_syscall(long int number, va_list args)
 	case TSOCKS_NR_ACCEPT4:
 		ret = handle_accept4(args);
 		break;
+	case TSOCKS_NR_EPOLL_CREATE1:
+		ret = handle_epoll_create1(args);
+		break;
+	case TSOCKS_NR_EPOLL_WAIT:
+		ret = handle_epoll_wait(args);
+		break;
+	case TSOCKS_NR_EPOLL_PWAIT:
+		ret = handle_epoll_pwait(args);
+		break;
+	case TSOCKS_NR_EPOLL_CTL:
+		ret = handle_epoll_ctl(args);
+		break;
 #endif /* __linux__ */
 	default:
 		/*