commit 1065e551161dfaa8f28da89b64bb57a3ea22d5df
Author: David Goulet <[email protected]>
Date: Wed Nov 6 18:49:42 2013 -0500
Add __syscall support for *BSD systems
Fixes #17
Signed-off-by: David Goulet <[email protected]>
---
src/lib/syscall.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++++
src/lib/torsocks.h | 26 ++++++++++++++++++
2 files changed, 104 insertions(+)
diff --git a/src/lib/syscall.c b/src/lib/syscall.c
index 67d3de2..adc433b 100644
--- a/src/lib/syscall.c
+++ b/src/lib/syscall.c
@@ -68,6 +68,7 @@ static LIBC_CONNECT_RET_TYPE handle_connect(va_list args)
return tsocks_connect(sockfd, addr, addrlen);
}
+#if (defined(__linux__) || defined(__darwin__))
/*
* Handle mmap(2) syscall.
*/
@@ -87,6 +88,7 @@ static LIBC_SYSCALL_RET_TYPE handle_mmap(va_list args)
return (LIBC_SYSCALL_RET_TYPE) mmap(addr, len, prot, flags, fd, offset);
}
+#endif /* __linux__, __darwin__ */
/*
* Handle munmap(2) syscall.
@@ -120,6 +122,14 @@ LIBC_SYSCALL_RET_TYPE tsocks_syscall(long int __number,
va_list args)
ret = handle_close(args);
break;
case TSOCKS_NR_MMAP:
+#if (defined(__NetBSD__) || defined(__FreeBSD__)) && defined(__x86_64)
+ /*
+ * On an 64 bit *BSD system, __syscall(2) should be used for
mmap().
+ * This is NOT suppose to happen but for protection we deny
that call.
+ */
+ ret = -1;
+ errno = ENOSYS;
+#else
/*
* The mmap/munmap syscall are handled here for a very specific
case so
* buckle up here for the explanation :).
@@ -141,6 +151,7 @@ LIBC_SYSCALL_RET_TYPE tsocks_syscall(long int __number,
va_list args)
* own memory using mmap() called by syscall(). Same for
munmap().
*/
ret = handle_mmap(args);
+#endif /* __NetBSD__, __FreeBSD__, __x86_64 */
break;
case TSOCKS_NR_MUNMAP:
ret = handle_munmap(args);
@@ -174,3 +185,70 @@ LIBC_SYSCALL_DECL
return ret;
}
+
+/* Only used for *BSD systems. */
+#if (defined(__NetBSD__) || defined(__FreeBSD__))
+
+/* __syscall(2) */
+TSOCKS_LIBC_DECL(__syscall, LIBC___SYSCALL_RET_TYPE, LIBC___SYSCALL_SIG)
+
+/*
+ * Handle *BSD mmap(2) syscall.
+ */
+static LIBC___SYSCALL_RET_TYPE handle_bsd_mmap(va_list args)
+{
+ void *addr;
+ size_t len;
+ int prot, flags, fd;
+ off_t offset;
+
+ addr = va_arg(args, __typeof__(addr));
+ len = va_arg(args, __typeof__(len));
+ prot = va_arg(args, __typeof__(prot));
+ flags = va_arg(args, __typeof__(flags));
+ fd = va_arg(args, __typeof__(fd));
+ offset = va_arg(args, __typeof__(offset));
+
+ return (LIBC___SYSCALL_RET_TYPE) mmap(addr, len, prot, flags, fd,
offset);
+}
+
+LIBC___SYSCALL_RET_TYPE tsocks___syscall(quad_t __number, va_list args)
+{
+ LIBC_SYSCALL_RET_TYPE ret;
+
+ switch (__number) {
+ case TSOCKS_NR_MMAP:
+ /*
+ * Please see the mmap comment in the syscall() function to
understand
+ * why mmap is being hijacked.
+ */
+ ret = handle_bsd_mmap(args);
+ break;
+ default:
+ /*
+ * Deny call since we have no idea if this call can leak or not
data
+ * off the Tor network.
+ */
+ WARN("[syscall] Unsupported __syscall number %ld. Denying the
call",
+ __number);
+ ret = -1;
+ errno = ENOSYS;
+ break;
+ }
+
+ return ret;
+}
+
+LIBC___SYSCALL_DECL
+{
+ LIBC___SYSCALL_RET_TYPE ret;
+ va_list args;
+
+ va_start(args, __number);
+ ret = tsocks___syscall(__number, args);
+ va_end(args);
+
+ return ret;
+}
+
+#endif /* __NetBSD__, __FreeBSD__ */
diff --git a/src/lib/torsocks.h b/src/lib/torsocks.h
index 78dc3ec..d724a77 100644
--- a/src/lib/torsocks.h
+++ b/src/lib/torsocks.h
@@ -208,6 +208,25 @@ struct hostent **__result, int *__h_errnop
#endif /* __GLIBC__ && __FreeBSD_kernel__ */
+/* __syscall(2) */
+#if defined(__FreeBSD__)
+
+#define LIBC___SYSCALL_NAME __syscall
+#define LIBC___SYSCALL_NAME_STR XSTR(LIBC___SYSCALL_NAME)
+#define LIBC___SYSCALL_RET_TYPE off_t
+#define LIBC___SYSCALL_SIG quad_t __number, ...
+#define LIBC___SYSCALL_ARGS __number
+
+#elif defined(__NetBSD__)
+
+#define LIBC___SYSCALL_NAME __syscall
+#define LIBC___SYSCALL_NAME_STR XSTR(LIBC___SYSCALL_NAME)
+#define LIBC___SYSCALL_RET_TYPE quad_t
+#define LIBC___SYSCALL_SIG quad_t __number, ...
+#define LIBC___SYSCALL_ARGS __number
+
+#endif /* __FreeBSD__, __NetBSD__ */
+
/*
* The following defines are libc function declarations using the macros
* defined above on a per OS basis.
@@ -241,6 +260,13 @@ extern TSOCKS_LIBC_DECL(syscall, LIBC_SYSCALL_RET_TYPE,
LIBC_SYSCALL_SIG)
#define LIBC_SYSCALL_DECL \
LIBC_SYSCALL_RET_TYPE LIBC_SYSCALL_NAME(LIBC_SYSCALL_SIG)
+/* __syscall(2) */
+#if (defined(__FreeBSD__) || defined(__NetBSD__))
+extern TSOCKS_LIBC_DECL(__syscall, LIBC___SYSCALL_RET_TYPE, LIBC___SYSCALL_SIG)
+#define LIBC___SYSCALL_DECL \
+ LIBC___SYSCALL_RET_TYPE LIBC___SYSCALL_NAME(LIBC___SYSCALL_SIG)
+#endif /* __FreeBSD__, __NetBSD__ */
+
/* close(2) */
extern TSOCKS_LIBC_DECL(close, LIBC_CLOSE_RET_TYPE, LIBC_CLOSE_SIG)
TSOCKS_DECL(close, LIBC_CLOSE_RET_TYPE, LIBC_CLOSE_SIG)
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