From 82b77505f9420f11d614c2ae0f74153ca4ee3cb5 Mon Sep 17 00:00:00 2001
From: Stefano Brivio <sbrivio@redhat.com>
Date: Tue, 2 May 2023 09:48:50 +0200
Subject: cooker updates spilling all over the place

Only tangentially related:

- make seitan C99 again, so that I can build cooker without warnings

- make Makefiles make use of the usual conventions about assigning
  directory paths in variables, drop numbers.h as requirement for
  cooker and make it convenient to run stand-alone Makefiles

- fix up nr_syscalls.sh to be POSIX, otherwise it will give syntax
  errors on my system

- define a single, common way to refer to offsets in gluten, and
  functions to use those offsets in a safe way. Immediates are gone:
  cooker will write any bit of "data" to the read-only section

- call const what has to be const

- define on-disk layout for gluten

- add OP_NR (to check syscall numbers), rename OP_COPY_ARGS to
  OP_LOAD (it loads _selected_ stuff from arguments)

As for cooker itself:

- drop ARG_ and arg_ prefixes from struct names, and similar

- add/rework functions to build OP_NR, OP_LOAD, OP_CMP, and to
  write constant data to gluten

- add parsing for "compound" arguments, but that's not completely
  hooked into evaluation for numeric arguments yet

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
---
 cooker/emit.c | 94 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 87 insertions(+), 7 deletions(-)

(limited to 'cooker/emit.c')

diff --git a/cooker/emit.c b/cooker/emit.c
index a82529c..8c35f1d 100644
--- a/cooker/emit.c
+++ b/cooker/emit.c
@@ -2,7 +2,7 @@
 
 /* seitan - Syscall Expressive Interpreter, Transformer and Notifier
  *
- * cooker/emit.c - Generate gluten (bytecode) instructions
+ * cooker/emit.c - Generate gluten (bytecode) instructions and read-only data
  *
  * Copyright 2023 Red Hat GmbH
  * Author: Stefano Brivio <sbrivio@redhat.com>
@@ -11,17 +11,97 @@
 #include "cooker.h"
 #include "gluten.h"
 #include "util.h"
+#include "emit.h"
 
-int emit_nr(struct gluten_ctx *g, long number)
+static const char *type_str[] = {
+	"INT",  "INTMASK",  "INTFLAGS",
+	"U32",  "U32MASK",  "U32FLAGS",
+	"LONG", "LONGMASK", "LONGFLAGS",
+	"STRING",
+	"STRUCT", "SELECT",
+	"PID",
+	"PORT", "IPV4", "IPV6",
+	"FDPATH",
+	NULL
+};
+
+static const char *cmp_type_str[] = { "EQ", "GT", "GE", "LT", "LE", NULL };
+
+void emit_nr(struct gluten_ctx *g, long number)
+{
+	struct op_nr *nr = (struct op_nr *)gluten_ptr(&g->g, g->ip);
+
+	nr->nr = number;
+	nr->no_match.type = OFFSET_INSTRUCTION;
+	nr->no_match.offset = NEXT_BLOCK;
+
+	debug("   %i: OP_NR %li, < >", g->ip.offset, number);
+
+	if (++g->ip.offset > INST_MAX)
+		die("Too many instructions");
+}
+
+void emit_load(struct gluten_ctx *g, struct gluten_offset dst,
+	       int index, size_t len)
+{
+	struct op_load *load = (struct op_load *)gluten_ptr(&g->g, g->ip);
+
+	load->src.type = OFFSET_SECCOMP_DATA;
+	load->src.offset = index;
+
+	load->dst = dst;
+
+	debug("   %i: OP_LOAD #%i < %i (%lu)", g->ip.offset, dst.offset,
+					       index, len);
+
+	if (++g->ip.offset > INST_MAX)
+		die("Too many instructions");
+}
+
+void emit_cmp(struct gluten_ctx *g, enum op_cmp_type cmp,
+	      struct gluten_offset x, struct gluten_offset y, size_t size,
+	      enum jump_type jmp)
 {
-	debug("   %i: OP_NR %li, < >", g->ip++, number);
+	struct op_cmp *op = (struct op_cmp *)gluten_ptr(&g->g, g->ip);
+
+	op->x = x;
+	op->y = y;
+	op->size = size;
+	op->cmp = cmp;
+	op->jmp = jmp;
+
+	debug("   %i: OP_CMP (#%lu) %%%lu %s %%%lu", g->ip.offset, size,
+	      x.offset, cmp_type_str[cmp], y.offset);
 
-	return 0;
+	if (++g->ip.offset > INST_MAX)
+		die("Too many instructions");
 }
 
-int emit_load(struct gluten_ctx *g, int offset, int index, size_t len)
+void emit_cmp_field(struct gluten_ctx *g, enum op_cmp_type cmp,
+		    struct field *field,
+		    struct gluten_offset base, struct gluten_offset match,
+		    enum jump_type jmp)
 {
-	debug("   %i: OP_LOAD #%i < %i (%lu)", g->ip++, offset, index, len);
+	base.offset += field->offset;
+
+	emit_cmp(g, cmp, base, match,
+		 field->strlen ? field->strlen : gluten_size[field->type],
+		 jmp);
+}
+
+struct gluten_offset emit_data(struct gluten_ctx *g, enum type type,
+			       union value *value)
+{
+	void *p = gluten_ptr(&g->g, g->cp);
+	struct gluten_offset ret = g->cp;
+
+	if (type == INT) {
+		*(int *)p = value->v_int;
+		debug("   C#%i: (%s) %i", g->cp.offset, type_str[type],
+		      value->v_int);
+		if ((g->cp.offset += sizeof(int)) > RO_DATA_SIZE)
+			die("   Read-only data section exceeded");
+	}
 
-	return 0;
+	return ret;
 }
-- 
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