diff --git a/fastrpc/iobuffer.c b/fastrpc/iobuffer.c
new file mode 100644
index 0000000..c38fa86
--- /dev/null
+++ b/fastrpc/iobuffer.c
@@ -0,0 +1,133 @@
+/*
+ * FastRPC reverse tunnel - argument decoder
+ *
+ * Copyright (C) 2023 Richard Acayan
+ *
+ * This file is part of sensh.
+ *
+ * Sensh is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see .
+ */
+
+#include
+#include
+#include
+#include
+
+#include "iobuffer.h"
+
+// See fastrpc.git/inc/remote.h
+#define REMOTE_SCALARS_INBUFS(sc) (((sc) >> 16) & 0xff)
+
+#define MIN(x, y) (((x) < (y)) ? (x) : (y))
+
+static size_t consume_size(struct fastrpc_decoder_context *ctx, size_t len, char *buf)
+{
+ size_t segment;
+
+ segment = MIN(len, 4 - ctx->size_off);
+ memcpy(&(&ctx->size)[ctx->size_off], buf, segment);
+ ctx->size_off = (ctx->size_off + segment) % 4;
+ ctx->align = (ctx->align + segment) & 0x7;
+
+ return segment;
+}
+
+static void try_populate_inbuf(struct fastrpc_decoder_context *ctx)
+{
+ if (!ctx->size_off) {
+ ctx->inbufs[ctx->idx].s = ctx->size;
+ ctx->inbufs[ctx->idx].p = malloc(ctx->size);
+ }
+}
+
+static size_t consume_alignment(struct fastrpc_decoder_context *ctx, size_t len)
+{
+ size_t segment = 0;
+
+ if (ctx->align) {
+ segment = MIN(len, 8 - ctx->align);
+ ctx->align = (ctx->align + segment) & 0x7;
+ }
+
+ return segment;
+}
+
+static size_t consume_buf(struct fastrpc_decoder_context *ctx, size_t len, char *buf)
+{
+ size_t segment;
+
+ segment = MIN(len, ctx->size - ctx->buf_off);
+ memcpy(&ctx->inbufs[ctx->idx].p[ctx->buf_off], buf, segment);
+
+ if (ctx->buf_off + segment >= ctx->size) {
+ ctx->size = 0;
+ ctx->buf_off = 0;
+ ctx->idx++;
+ } else {
+ ctx->buf_off = ctx->buf_off + segment;
+ }
+
+ ctx->align = (ctx->align + segment) & 0x7;
+
+ return segment;
+}
+
+struct fastrpc_decoder_context *inbuf_decode_start(uint32_t sc)
+{
+ struct fastrpc_decoder_context *ctx;
+ int n_inbufs;
+
+ ctx = malloc(sizeof(*ctx));
+ if (ctx == NULL)
+ return ctx;
+
+ ctx->idx = 0;
+ ctx->size = 0;
+ ctx->n_inbufs = REMOTE_SCALARS_INBUFS(sc);
+
+ ctx->size_off = 0;
+ ctx->buf_off = 0;
+ ctx->align = 0;
+
+ ctx->inbufs = malloc(sizeof(*ctx->inbufs) * ctx->n_inbufs);
+ if (ctx->inbufs == NULL)
+ goto err;
+
+ return ctx;
+
+err:
+ free(ctx);
+ return NULL;
+}
+
+void inbuf_decode_free(struct fastrpc_decoder_context *ctx)
+{
+ free(ctx->inbufs);
+ free(ctx);
+}
+
+void inbuf_decode(struct fastrpc_decoder_context *ctx, size_t len, char *buf)
+{
+ size_t off = 0;
+
+ while (off < len && ctx->idx < ctx->n_inbufs) {
+ if (!ctx->size || ctx->size_off) {
+ off += consume_size(ctx, len - off, &buf[off]);
+ try_populate_inbuf(ctx);
+ } else {
+ off += consume_alignment(ctx, len - off);
+ off += consume_buf(ctx, len - off, &buf[off]);
+ }
+ }
+}
diff --git a/fastrpc/iobuffer.h b/fastrpc/iobuffer.h
new file mode 100644
index 0000000..bb4dfe5
--- /dev/null
+++ b/fastrpc/iobuffer.h
@@ -0,0 +1,27 @@
+#ifndef IOBUFFER_H
+#define IOBUFFER_H
+
+#include
+#include
+
+struct fastrpc_io_buffer {
+ size_t s;
+ char *p;
+};
+
+struct fastrpc_decoder_context {
+ struct fastrpc_io_buffer *inbufs;
+ int idx;
+ size_t size;
+ int n_inbufs;
+
+ off_t size_off;
+ off_t buf_off;
+ off_t align;
+};
+
+struct fastrpc_decoder_context *inbuf_decode_start(uint32_t sc);
+void inbuf_decode(struct fastrpc_decoder_context *ctx, size_t len, char *buf);
+void inbuf_decode_free(struct fastrpc_decoder_context *ctx);
+
+#endif
diff --git a/fastrpc/listener.c b/fastrpc/listener.c
index 203a1a3..9e483c3 100644
--- a/fastrpc/listener.c
+++ b/fastrpc/listener.c
@@ -21,6 +21,7 @@
#include "fastrpc.h"
#include "fastrpc_adsp_listener.h"
+#include "iobuffer.h"
static int adsp_listener_init2(int fd)
{
@@ -50,6 +51,7 @@ static int adsp_listener_next2(int fd,
int run_fastrpc_listener(int fd)
{
+ struct fastrpc_decoder_context *ctx;
uint32_t result = 0xffffffff;
uint32_t handle;
uint32_t rctx = 0;
@@ -71,6 +73,18 @@ int run_fastrpc_listener(int fd)
0, outbuf,
&rctx, &handle, &sc,
&inbufs_len, 256, inbufs);
+ if (ret)
+ break;
+
+ ctx = inbuf_decode_start(sc);
+ if (!ctx) {
+ ret = -1;
+ break;
+ }
+
+ inbuf_decode(ctx, inbufs_len, inbufs);
+
+ inbuf_decode_free(ctx);
}
return ret;