api: add syscall resolution functions that take an architecture argument

Similar to the existing seccomp_syscall_resolve_name() function, but
they work for arbitrary architectures (assuming libseccomp support of
course) and not just the native architecture.

Signed-off-by: Paul Moore <pmoore@redhat.com>

4 files changed, 92 insertions, 11 deletions

diff --git a/include/seccomp.h b/include/seccomp.h
index b09f3d3..136643e 100644
--- a/include/seccomp.h
+++ b/include/seccomp.h
@@ -1,7 +1,7 @@
 /**
  * Seccomp Library
  *
- * Copyright (c) 2012 Red Hat <pmoore@redhat.com>
+ * Copyright (c) 2012,2013 Red Hat <pmoore@redhat.com>
  * Author: Paul Moore <pmoore@redhat.com>
  */
 
@@ -313,6 +313,30 @@ int seccomp_attr_set(scmp_filter_ctx ctx,
 		     enum scmp_filter_attr attr, uint32_t value);
 
 /**
+ * Resolve a syscall number to a name
+ * @param arch_token the architecture token, e.g. SCMP_ARCH_*
+ * @param num the syscall number
+ *
+ * Resolve the given syscall number to the syscall name for the given
+ * architecture; it is up to the caller to free the returned string.  Returns
+ * the syscall name on success, NULL on failure.
+ *
+ */
+char *seccomp_syscall_resolve_num_arch(uint32_t arch_token, int num);
+
+/**
+ * Resolve a syscall name to a number
+ * @param arch_token the architecture token, e.g. SCMP_ARCH_*
+ * @param name the syscall name
+ *
+ * Resolve the given syscall name to the syscall number for the given
+ * architecture.  Returns the syscall number on success, including negative
+ * pseudo syscall numbers (e.g. __PNR_*); returns __NR_SCMP_ERROR on failure.
+ *
+ */
+int seccomp_syscall_resolve_name_arch(uint32_t arch_token, const char *name);
+
+/**
  * Resolve a syscall name to a number
  * @param name the syscall name
  *
diff --git a/src/api.c b/src/api.c
index 8f4d46b..8f03c3d 100644
--- a/src/api.c
+++ b/src/api.c
@@ -1,7 +1,7 @@
 /**
  * Seccomp Library API
  *
- * Copyright (c) 2012 Red Hat <pmoore@redhat.com>
+ * Copyright (c) 2012,2013 Red Hat <pmoore@redhat.com>
  * Author: Paul Moore <pmoore@redhat.com>
  */
 
@@ -255,12 +255,49 @@ int seccomp_attr_set(scmp_filter_ctx ctx,
 }
 
 /* NOTE - function header comment in include/seccomp.h */
-int seccomp_syscall_resolve_name(const char *name)
+char *seccomp_syscall_resolve_num_arch(uint32_t arch_token, int num)
 {
+	const struct arch_def *arch;
+	const char *name;
+
+	if (arch_token == 0)
+		arch_token = arch_def_native.token;
+	if (arch_valid(arch_token))
+		return NULL;
+	arch = arch_def_lookup(arch_token);
+	if (arch == NULL)
+		return NULL;
+
+	name = arch_syscall_resolve_num(arch, num);
 	if (name == NULL)
+		return NULL;
+
+	return strdup(name);
+}
+
+/* NOTE - function header comment in include/seccomp.h */
+int seccomp_syscall_resolve_name_arch(uint32_t arch_token, const char *name)
+{
+	const struct arch_def *arch;
+
+	if (name == NULL)
+		return -EINVAL;
+
+	if (arch_token == 0)
+		arch_token = arch_def_native.token;
+	if (arch_valid(arch_token))
 		return -EINVAL;
+	arch = arch_def_lookup(arch_token);
+	if (arch == NULL)
+		return -EFAULT;
+
+	return arch_syscall_resolve_name(arch, name);
+}
 
-	return arch_syscall_resolve_name(&arch_def_native, name);
+/* NOTE - function header comment in include/seccomp.h */
+int seccomp_syscall_resolve_name(const char *name)
+{
+	return seccomp_syscall_resolve_name_arch(SCMP_ARCH_NATIVE, name);
 }
 
 /* NOTE - function header comment in include/seccomp.h */
diff --git a/src/python/libseccomp.pxd b/src/python/libseccomp.pxd
index b5ca659..1af4a30 100644
--- a/src/python/libseccomp.pxd
+++ b/src/python/libseccomp.pxd
@@ -1,7 +1,7 @@
 #
 # Seccomp Library Python Bindings
 #
-# Copyright (c) 2012 Red Hat <pmoore@redhat.com>
+# Copyright (c) 2012,2013 Red Hat <pmoore@redhat.com>
 # Author: Paul Moore <pmoore@redhat.com>
 #
 
@@ -77,6 +77,8 @@ cdef extern from "seccomp.h":
     int seccomp_attr_set(scmp_filter_ctx ctx,
                          scmp_filter_attr attr, uint32_t value)
 
+    char *seccomp_syscall_resolve_num_arch(uint32_t arch_token, int num)
+    int seccomp_syscall_resolve_name_arch(uint32_t arch_token, char *name)
     int seccomp_syscall_resolve_name(char *name)
     int seccomp_syscall_priority(scmp_filter_ctx ctx,
                                  int syscall, uint8_t priority)
diff --git a/src/python/seccomp.pyx b/src/python/seccomp.pyx
index 1b6f368..9ceee14 100644
--- a/src/python/seccomp.pyx
+++ b/src/python/seccomp.pyx
@@ -1,7 +1,7 @@
 #
 # Seccomp Library Python Bindings
 #
-# Copyright (c) 2012 Red Hat <pmoore@redhat.com>
+# Copyright (c) 2012,2013 Red Hat <pmoore@redhat.com>
 # Author: Paul Moore <pmoore@redhat.com>
 #
 
@@ -68,7 +68,7 @@ Example:
     f.load()
 """
 __author__ =  'Paul Moore <paul@paul-moore.com>'
-__date__ = "31 October 2012"
+__date__ = "7 January 2013"
 
 from libc.stdint cimport uint32_t
 import errno
@@ -99,6 +99,24 @@ def system_arch():
     """
     return libseccomp.seccomp_arch_native()
 
+def resolve_syscall(arch, syscall):
+    """ Resolve the syscall.
+
+    Arguments:
+    arch - the architecture value, e.g. Arch.*
+    syscall - the syscall name or number
+
+    Description:
+    Resolve an architecture's syscall name to the correct number or the
+    syscall number to the correct name.
+    """
+    if (isinstance(syscall, basestring)):
+        return libseccomp.seccomp_syscall_resolve_name_arch(arch, syscall)
+    elif (isinstance(syscall, int)):
+        return libseccomp.seccomp_syscall_resolve_num_arch(arch, syscall)
+    else:
+        raise TypeError("Syscall must either be an int or str type")
+
 cdef class Arch:
     """ Python object representing the SyscallFilter architecture values.
 
@@ -349,14 +367,14 @@ cdef class SyscallFilter:
         from 0 to 255 inclusive.
         """
         if priority < 0 or priority > 255:
-            raise ValueError("Syscall priority must be between 0 and 255");
+            raise ValueError("Syscall priority must be between 0 and 255")
         if isinstance(syscall, str):
             syscall_str = syscall.encode()
             syscall_num = libseccomp.seccomp_syscall_resolve_name(syscall_str)
         elif isinstance(syscall, int):
             syscall_num = syscall
         else:
-            raise TypeError("Syscall must either be an int or str type");
+            raise TypeError("Syscall must either be an int or str type")
         rc = libseccomp.seccomp_syscall_priority(self._ctx,
                                                  syscall_num, priority)
         if rc != 0:
@@ -389,7 +407,7 @@ cdef class SyscallFilter:
         elif isinstance(syscall, int):
             syscall_num = syscall
         else:
-            raise TypeError("Syscall must either be an int or str type");
+            raise TypeError("Syscall must either be an int or str type")
         """ NOTE: the code below exists solely to deal with the varadic
         nature of seccomp_rule_add() function and the inability of Cython
         to handle this automatically """
@@ -468,7 +486,7 @@ cdef class SyscallFilter:
         elif isinstance(syscall, int):
             syscall_num = syscall
         else:
-            raise TypeError("Syscall must either be an int or str type");
+            raise TypeError("Syscall must either be an int or str type")
         """ NOTE: the code below exists solely to deal with the varadic
         nature of seccomp_rule_add_exact() function and the inability of
         Cython to handle this automatically """