cooker, seitan: Now with 100% more gluten

Pseudorandom changes and progress around cooker and seitan:

- cooker:
  - rename matching functions, split match.c
  - fix up SELECT semantics
  - add some form of handling for all syscalls in the example
    (some stubs)
  - OP_CMP for all basic and compound types except for flags
  - link jumps to next block and next match
  - completed implementation of tags
  - gluten write
  - filter clean-ups, write filters (probably not working)

- seitan:
  - load gluten and source instructions and data from there

$ ./seitan-cooker cooker/example.hjson example.gluten example.bpf
Parsing block 0
 Parsing match 0: connect
  Found description for connect
   0: OP_NR: if syscall number is not 0, jump to next block
  Parsing match argument fd
   setting tag reference 'fd'
   tag 'fd' now refers to seccomp data at 0
  Parsing match argument addr
   allocating 128 at offset 0
   1: OP_LOAD: #0 < args[1] (size: 128)
   C#0: (INT) 1
   2: OP_CMP: if temporary data: #0 NE (size: 4) read-only data: #0, jump to next block
   C#4: (STRING:24) /var/run/pr-helper.sock
   3: OP_CMP: if temporary data: #0 NE (size: 24) read-only data: #4, jump to next block
   Linking match...
   Linking block...
    linked jump of instruction #0 to #4
    linked jump of instruction #2 to #4
    linked jump of instruction #3 to #4
Parsing block 1
 Parsing match 0: ioctl
  Found description for ioctl
   4: OP_NR: if syscall number is not 112, jump to next block
  Parsing match argument path
  Parsing match argument request
   C#28: (INT) 1074025674
   5: OP_CMP: if seccomp data: #1 NE (size: 4) read-only data: #28, jump to next block
  Parsing match argument ifr
   allocating 40 at offset 128
   6: OP_LOAD: #128 < args[2] (size: 40)
   C#32: (STRING:5) tap0
   7: OP_CMP: if temporary data: #128 NE (size: 5) read-only data: #32, jump to next block
   C#37: (INT) 1
   8: OP_CMP: if temporary data: #128 NE (size: 4) read-only data: #37, jump to next block
   Linking match...
   Linking block...
    linked jump of instruction #4 to #9
    linked jump of instruction #5 to #9
    linked jump of instruction #7 to #9
    linked jump of instruction #8 to #9
Parsing block 2
 Parsing match 0: unshare
  Found description for unshare
   9: OP_NR: if syscall number is not 164, jump to next block
  Parsing match argument flags
   Linking match...
   Linking block...
    linked jump of instruction #9 to #10
Parsing block 3
 Parsing match 0: unshare
  Found description for unshare
   10: OP_NR: if syscall number is not 164, jump to next block
  Parsing match argument flags
   Linking match...
   Linking block...
    linked jump of instruction #10 to #11
Parsing block 4
 Parsing match 0: mknod
  Found description for mknod
   11: OP_NR: if syscall number is not 164, jump to next block
  Parsing match argument path
   allocating 1 at offset 168
   12: OP_LOAD: #168 < args[0] (size: 1)
   setting tag reference 'path'
   tag 'path' now refers to temporary data at 168
  Parsing match argument mode
  Parsing match argument major
  Parsing match argument minor
   setting tag reference 'minor'
   tag 'minor' now refers to seccomp data at 2
   Linking match...
   Linking block...
    linked jump of instruction #11 to #13

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

2 files changed, 12 insertions, 3 deletions

diff --git a/common/gluten.h b/common/gluten.h
index 3df638e..ff29caa 100644
--- a/common/gluten.h
+++ b/common/gluten.h
@@ -10,6 +10,7 @@
 #include <stddef.h>
 #include <stdint.h>
 #include <stdbool.h>
+#include <sys/types.h>
 #include <linux/seccomp.h>
 
 #include <stdio.h>
@@ -39,6 +40,8 @@ enum gluten_offset_type {
 	OFFSET_TYPE_MAX = OFFSET_INSTRUCTION,
 };
 
+extern const char *gluten_offset_name[OFFSET_TYPE_MAX + 1];
+
 struct gluten_offset {
 #ifdef __GNUC__
 	enum gluten_offset_type type : BITS_PER_NUM(OFFSET_TYPE_MAX);
@@ -89,6 +92,8 @@ struct op_context {
 };
 
 enum op_type {
+	OP_END = 0,
+	OP_NR,
 	OP_CALL,
 	OP_BLOCK,
 	OP_CONT,
@@ -98,7 +103,6 @@ enum op_type {
 	OP_LOAD,
 	OP_CMP,
 	OP_RESOLVEDFD,
-	OP_END,
 };
 
 struct op_nr {
@@ -147,7 +151,7 @@ struct op_cmp {
 	struct gluten_offset y;
 	size_t size;
 	enum op_cmp_type cmp;
-	unsigned int jmp;
+	struct gluten_offset jmp;
 };
 
 struct op_resolvedfd {
@@ -237,7 +241,7 @@ static inline const void *gluten_ptr(const struct seccomp_data *s,
 	if (!is_offset_valid(x))
 		return NULL;
 
-	if(x.type == OFFSET_SECCOMP_DATA && s == NULL)
+	if (x.type == OFFSET_SECCOMP_DATA && s == NULL)
 		return NULL;
 
 	switch (x.type) {
diff --git a/common/util.c b/common/util.c
index a2ecce0..3a4b2e5 100644
--- a/common/util.c
+++ b/common/util.c
@@ -12,6 +12,8 @@
 #include <stdarg.h>
 #include <string.h>
 
+#include "gluten.h"
+
 #define logfn(name)							\
 void name(const char *format, ...) {					\
 	va_list args;							\
@@ -27,3 +29,6 @@ logfn(err)
 logfn(info)
 logfn(debug)
 
+const char *gluten_offset_name[OFFSET_TYPE_MAX + 1] = {
+	"read-only data", "temporary data", "seccomp data", "instruction area"
+};