include lua_cmsgpack and implement select binding

8 files changed, 1061 insertions, 3 deletions

diff --git a/src/common/include/assert.h b/src/common/include/assert.h
index 655d6f6..0e126dd 100644
--- a/src/common/include/assert.h
+++ b/src/common/include/assert.h
@@ -1,5 +1,6 @@
 #pragma once
 
 #include <kogata/debug.h>
+#define assert ASSERT
 
 /* vim: set sts=0 ts=4 sw=4 tw=0 noet :*/
diff --git a/src/common/libc/printf.c b/src/common/libc/printf.c
index fbebafe..8ec78d7 100644
--- a/src/common/libc/printf.c
+++ b/src/common/libc/printf.c
@@ -1,5 +1,6 @@
 #include <stdarg.h>
 #include <stdbool.h>
+#include <ctype.h>
 
 #include <kogata/debug.h>
 #include <kogata/printf.h>
@@ -59,8 +60,11 @@ int vcprintf(int (*putc_fun)(int c, void* p), void* p, const char* format, va_li
 	for(i = 0; format[i] != '\0' ; i++) {
 		if (format[i] == '%') {
 			i++;
+			int na = -1;
+			int nb = -1;
 			int u = 0;
 			int l = 0;
+			bool dotspec = false;
 			bool spec = true;
 			while (spec) {
 				if (format[i] == 'l') {
@@ -69,6 +73,18 @@ int vcprintf(int (*putc_fun)(int c, void* p), void* p, const char* format, va_li
 				} else if (format[i] == 'u') {
 					u = 1;
 					i++;
+				} else if (isdigit(format[i])) {
+					if (dotspec) {
+						if (nb == -1) nb = 0;
+						nb = nb * 10 + (format[i] - '0');
+					} else {
+						if (na == -1) na = 0;
+						na = na * 10 + (format[i] - '0');
+					}
+					i++;
+				} else if (format[i] == '.') {
+					dotspec = true;
+					i++;
 				} else {
 					spec = false;
 				}
@@ -112,7 +128,11 @@ int vcprintf(int (*putc_fun)(int c, void* p), void* p, const char* format, va_li
 				 for(; *string != '\0' ; string++)
 					 PUTCHAR(*string);
 			} else if (format[i] == 'x') {
-				unsigned int hexa = va_arg(ap,int);
+				unsigned long long int hexa;
+				if (l == 0) hexa = va_arg(ap, unsigned int);
+				if (l == 1) hexa = va_arg(ap, unsigned long int);
+				if (l == 2) hexa = va_arg(ap, unsigned long long int);
+
 				int had_nonzero = 0;
 				for(int j = 0; j < 8; j++) {
 					unsigned int nb = (unsigned int)(hexa << (j*4));
diff --git a/src/lib/include/math.h b/src/lib/include/math.h
index 4a23bd8..dfb515c 100644
--- a/src/lib/include/math.h
+++ b/src/lib/include/math.h
@@ -56,4 +56,6 @@ double exp(double x);
 double frexp(double x, int *exp);
 double pow(double x, double y);
 
+#define isinf(x) (0)
+
 /* vim: set sts=0 ts=4 sw=4 tw=0 noet :*/
diff --git a/src/sysbin/lx/lua_cmsgpack.c b/src/sysbin/lx/lua_cmsgpack.c
new file mode 100644
index 0000000..57c378e
--- /dev/null
+++ b/src/sysbin/lx/lua_cmsgpack.c
@@ -0,0 +1,967 @@
+#include <math.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <assert.h>
+
+#include <lua/lua.h>
+#include <lua/lauxlib.h>
+
+#define LUACMSGPACK_NAME        "lx.msg"
+#define LUACMSGPACK_SAFE_NAME   "cmsgpack_safe"
+#define LUACMSGPACK_VERSION     "lua-cmsgpack 0.4.0alex1"
+#define LUACMSGPACK_COPYRIGHT   "Copyright (C) 2012, Salvatore Sanfilippo, 2017, Alex Auvolat"
+#define LUACMSGPACK_DESCRIPTION "MessagePack C implementation for Lua"
+
+/* Allows a preprocessor directive to override MAX_NESTING */
+#ifndef LUACMSGPACK_MAX_NESTING
+    #define LUACMSGPACK_MAX_NESTING  16 /* Max tables nesting. */
+#endif
+
+/* Check if float or double can be an integer without loss of precision */
+#define IS_INT_TYPE_EQUIVALENT(x, T) (!isinf(x) && (T)(x) == (x))
+
+#define IS_INT64_EQUIVALENT(x) IS_INT_TYPE_EQUIVALENT(x, int64_t)
+#define IS_INT_EQUIVALENT(x) IS_INT_TYPE_EQUIVALENT(x, int)
+
+/* If size of pointer is equal to a 4 byte integer, we're on 32 bits. */
+#if UINTPTR_MAX == UINT_MAX
+    #define BITS_32 1
+#else
+    #define BITS_32 0
+#endif
+
+#if LUA_INT_TYPE == LUA_INT_LONGLONG
+    #define lua_pushunsigned(L, n) lua_pushinteger(L, n)
+#else
+    #define lua_pushunsigned(L, n) { if ((uint64_t)(n) <= (uint64_t)LUA_MAXINTEGER) lua_pushinteger(L, n); else lua_pushnumber(L, n); }
+#endif
+
+/* =============================================================================
+ * MessagePack implementation and bindings for Lua 5.1/5.2.
+ * Copyright(C) 2012 Salvatore Sanfilippo <antirez@gmail.com>
+ *
+ * http://github.com/antirez/lua-cmsgpack
+ *
+ * For MessagePack specification check the following web site:
+ * http://wiki.msgpack.org/display/MSGPACK/Format+specification
+ *
+ * See Copyright Notice at the end of this file.
+ *
+ * CHANGELOG:
+ * 19-Feb-2012 (ver 0.1.0): Initial release.
+ * 20-Feb-2012 (ver 0.2.0): Tables encoding improved.
+ * 20-Feb-2012 (ver 0.2.1): Minor bug fixing.
+ * 20-Feb-2012 (ver 0.3.0): Module renamed lua-cmsgpack (was lua-msgpack).
+ * 04-Apr-2014 (ver 0.3.1): Lua 5.2 support and minor bug fix.
+ * 07-Apr-2014 (ver 0.4.0): Multiple pack/unpack, lua allocator, efficiency.
+ * ========================================================================== */
+
+/* -------------------------- Endian conversion --------------------------------
+ * We use it only for floats and doubles, all the other conversions performed
+ * in an endian independent fashion. So the only thing we need is a function
+ * that swaps a binary string if arch is little endian (and left it untouched
+ * otherwise). */
+
+/* Reverse memory bytes if arch is little endian. Given the conceptual
+ * simplicity of the Lua build system we prefer check for endianess at runtime.
+ * The performance difference should be acceptable. */
+void memrevifle(void *ptr, size_t len) {
+    unsigned char   *p = (unsigned char *)ptr,
+                    *e = (unsigned char *)p+len-1,
+                    aux;
+    int test = 1;
+    unsigned char *testp = (unsigned char*) &test;
+
+    if (testp[0] == 0) return; /* Big endian, nothing to do. */
+    len /= 2;
+    while(len--) {
+        aux = *p;
+        *p = *e;
+        *e = aux;
+        p++;
+        e--;
+    }
+}
+
+/* ---------------------------- String buffer ----------------------------------
+ * This is a simple implementation of string buffers. The only operation
+ * supported is creating empty buffers and appending bytes to it.
+ * The string buffer uses 2x preallocation on every realloc for O(N) append
+ * behavior.  */
+
+typedef struct mp_buf {
+    unsigned char *b;
+    size_t len, free;
+} mp_buf;
+
+void *mp_realloc(lua_State *L, void *target, size_t osize,size_t nsize) {
+    void *(*local_realloc) (void *, void *, size_t osize, size_t nsize) = NULL;
+    void *ud;
+
+    local_realloc = lua_getallocf(L, &ud);
+
+    return local_realloc(ud, target, osize, nsize);
+}
+
+mp_buf *mp_buf_new(lua_State *L) {
+    mp_buf *buf = NULL;
+
+    /* Old size = 0; new size = sizeof(*buf) */
+    buf = (mp_buf*)mp_realloc(L, NULL, 0, sizeof(*buf));
+
+    buf->b = NULL;
+    buf->len = buf->free = 0;
+    return buf;
+}
+
+void mp_buf_append(lua_State *L, mp_buf *buf, const unsigned char *s, size_t len) {
+    if (buf->free < len) {
+        size_t newsize = (buf->len+len)*2;
+
+        buf->b = (unsigned char*)mp_realloc(L, buf->b, buf->len + buf->free, newsize);
+        buf->free = newsize - buf->len;
+    }
+    memcpy(buf->b+buf->len,s,len);
+    buf->len += len;
+    buf->free -= len;
+}
+
+void mp_buf_free(lua_State *L, mp_buf *buf) {
+    mp_realloc(L, buf->b, buf->len + buf->free, 0); /* realloc to 0 = free */
+    mp_realloc(L, buf, sizeof(*buf), 0);
+}
+
+/* ---------------------------- String cursor ----------------------------------
+ * This simple data structure is used for parsing. Basically you create a cursor
+ * using a string pointer and a length, then it is possible to access the
+ * current string position with cursor->p, check the remaining length
+ * in cursor->left, and finally consume more string using
+ * mp_cur_consume(cursor,len), to advance 'p' and subtract 'left'.
+ * An additional field cursor->error is set to zero on initialization and can
+ * be used to report errors. */
+
+#define MP_CUR_ERROR_NONE   0
+#define MP_CUR_ERROR_EOF    1   /* Not enough data to complete operation. */
+#define MP_CUR_ERROR_BADFMT 2   /* Bad data format */
+
+typedef struct mp_cur {
+    const unsigned char *p;
+    size_t left;
+    int err;
+} mp_cur;
+
+void mp_cur_init(mp_cur *cursor, const unsigned char *s, size_t len) {
+    cursor->p = s;
+    cursor->left = len;
+    cursor->err = MP_CUR_ERROR_NONE;
+}
+
+#define mp_cur_consume(_c,_len) do { _c->p += _len; _c->left -= _len; } while(0)
+
+/* When there is not enough room we set an error in the cursor and return. This
+ * is very common across the code so we have a macro to make the code look
+ * a bit simpler. */
+#define mp_cur_need(_c,_len) do { \
+    if (_c->left < _len) { \
+        _c->err = MP_CUR_ERROR_EOF; \
+        return; \
+    } \
+} while(0)
+
+/* ------------------------- Low level MP encoding -------------------------- */
+
+void mp_encode_bytes(lua_State *L, mp_buf *buf, const unsigned char *s, size_t len) {
+    unsigned char hdr[5];
+    int hdrlen;
+
+    if (len < 32) {
+        hdr[0] = 0xa0 | (len&0xff); /* fix raw */
+        hdrlen = 1;
+    } else if (len <= 0xff) {
+        hdr[0] = 0xd9;
+        hdr[1] = len;
+        hdrlen = 2;
+    } else if (len <= 0xffff) {
+        hdr[0] = 0xda;
+        hdr[1] = (len&0xff00)>>8;
+        hdr[2] = len&0xff;
+        hdrlen = 3;
+    } else {
+        hdr[0] = 0xdb;
+        hdr[1] = (len&0xff000000)>>24;
+        hdr[2] = (len&0xff0000)>>16;
+        hdr[3] = (len&0xff00)>>8;
+        hdr[4] = len&0xff;
+        hdrlen = 5;
+    }
+    mp_buf_append(L,buf,hdr,hdrlen);
+    mp_buf_append(L,buf,s,len);
+}
+
+/* we assume IEEE 754 internal format for single and double precision floats. */
+void mp_encode_double(lua_State *L, mp_buf *buf, double d) {
+    unsigned char b[9];
+    float f = d;
+
+    assert(sizeof(f) == 4 && sizeof(d) == 8);
+    if (d == (double)f) {
+        b[0] = 0xca;    /* float IEEE 754 */
+        memcpy(b+1,&f,4);
+        memrevifle(b+1,4);
+        mp_buf_append(L,buf,b,5);
+    } else if (sizeof(d) == 8) {
+        b[0] = 0xcb;    /* double IEEE 754 */
+        memcpy(b+1,&d,8);
+        memrevifle(b+1,8);
+        mp_buf_append(L,buf,b,9);
+    }
+}
+
+void mp_encode_int(lua_State *L, mp_buf *buf, int64_t n) {
+    unsigned char b[9];
+    int enclen;
+
+    if (n >= 0) {
+        if (n <= 127) {
+            b[0] = n & 0x7f;    /* positive fixnum */
+            enclen = 1;
+        } else if (n <= 0xff) {
+            b[0] = 0xcc;        /* uint 8 */
+            b[1] = n & 0xff;
+            enclen = 2;
+        } else if (n <= 0xffff) {
+            b[0] = 0xcd;        /* uint 16 */
+            b[1] = (n & 0xff00) >> 8;
+            b[2] = n & 0xff;
+            enclen = 3;
+        } else if (n <= 0xffffffffLL) {
+            b[0] = 0xce;        /* uint 32 */
+            b[1] = (n & 0xff000000) >> 24;
+            b[2] = (n & 0xff0000) >> 16;
+            b[3] = (n & 0xff00) >> 8;
+            b[4] = n & 0xff;
+            enclen = 5;
+        } else {
+            b[0] = 0xcf;        /* uint 64 */
+            b[1] = (n & 0xff00000000000000LL) >> 56;
+            b[2] = (n & 0xff000000000000LL) >> 48;
+            b[3] = (n & 0xff0000000000LL) >> 40;
+            b[4] = (n & 0xff00000000LL) >> 32;
+            b[5] = (n & 0xff000000) >> 24;
+            b[6] = (n & 0xff0000) >> 16;
+            b[7] = (n & 0xff00) >> 8;
+            b[8] = n & 0xff;
+            enclen = 9;
+        }
+    } else {
+        if (n >= -32) {
+            b[0] = ((signed char)n);   /* negative fixnum */
+            enclen = 1;
+        } else if (n >= -128) {
+            b[0] = 0xd0;        /* int 8 */
+            b[1] = n & 0xff;
+            enclen = 2;
+        } else if (n >= -32768) {
+            b[0] = 0xd1;        /* int 16 */
+            b[1] = (n & 0xff00) >> 8;
+            b[2] = n & 0xff;
+            enclen = 3;
+        } else if (n >= -2147483648LL) {
+            b[0] = 0xd2;        /* int 32 */
+            b[1] = (n & 0xff000000) >> 24;
+            b[2] = (n & 0xff0000) >> 16;
+            b[3] = (n & 0xff00) >> 8;
+            b[4] = n & 0xff;
+            enclen = 5;
+        } else {
+            b[0] = 0xd3;        /* int 64 */
+            b[1] = (n & 0xff00000000000000LL) >> 56;
+            b[2] = (n & 0xff000000000000LL) >> 48;
+            b[3] = (n & 0xff0000000000LL) >> 40;
+            b[4] = (n & 0xff00000000LL) >> 32;
+            b[5] = (n & 0xff000000) >> 24;
+            b[6] = (n & 0xff0000) >> 16;
+            b[7] = (n & 0xff00) >> 8;
+            b[8] = n & 0xff;
+            enclen = 9;
+        }
+    }
+    mp_buf_append(L,buf,b,enclen);
+}
+
+void mp_encode_array(lua_State *L, mp_buf *buf, int64_t n) {
+    unsigned char b[5];
+    int enclen;
+
+    if (n <= 15) {
+        b[0] = 0x90 | (n & 0xf);    /* fix array */
+        enclen = 1;
+    } else if (n <= 65535) {
+        b[0] = 0xdc;                /* array 16 */
+        b[1] = (n & 0xff00) >> 8;
+        b[2] = n & 0xff;
+        enclen = 3;
+    } else {
+        b[0] = 0xdd;                /* array 32 */
+        b[1] = (n & 0xff000000) >> 24;
+        b[2] = (n & 0xff0000) >> 16;
+        b[3] = (n & 0xff00) >> 8;
+        b[4] = n & 0xff;
+        enclen = 5;
+    }
+    mp_buf_append(L,buf,b,enclen);
+}
+
+void mp_encode_map(lua_State *L, mp_buf *buf, int64_t n) {
+    unsigned char b[5];
+    int enclen;
+
+    if (n <= 15) {
+        b[0] = 0x80 | (n & 0xf);    /* fix map */
+        enclen = 1;
+    } else if (n <= 65535) {
+        b[0] = 0xde;                /* map 16 */
+        b[1] = (n & 0xff00) >> 8;
+        b[2] = n & 0xff;
+        enclen = 3;
+    } else {
+        b[0] = 0xdf;                /* map 32 */
+        b[1] = (n & 0xff000000) >> 24;
+        b[2] = (n & 0xff0000) >> 16;
+        b[3] = (n & 0xff00) >> 8;
+        b[4] = n & 0xff;
+        enclen = 5;
+    }
+    mp_buf_append(L,buf,b,enclen);
+}
+
+/* --------------------------- Lua types encoding --------------------------- */
+
+void mp_encode_lua_string(lua_State *L, mp_buf *buf) {
+    size_t len;
+    const char *s;
+
+    s = lua_tolstring(L,-1,&len);
+    mp_encode_bytes(L,buf,(const unsigned char*)s,len);
+}
+
+void mp_encode_lua_bool(lua_State *L, mp_buf *buf) {
+    unsigned char b = lua_toboolean(L,-1) ? 0xc3 : 0xc2;
+    mp_buf_append(L,buf,&b,1);
+}
+
+/* Lua 5.3 has a built in 64-bit integer type */
+void mp_encode_lua_integer(lua_State *L, mp_buf *buf) {
+#if (LUA_VERSION_NUM < 503) && BITS_32
+    lua_Number i = lua_tonumber(L,-1);
+#else
+    lua_Integer i = lua_tointeger(L,-1);
+#endif
+    mp_encode_int(L, buf, (int64_t)i);
+}
+
+/* Lua 5.2 and lower only has 64-bit doubles, so we need to
+ * detect if the double may be representable as an int
+ * for Lua < 5.3 */
+void mp_encode_lua_number(lua_State *L, mp_buf *buf) {
+    lua_Number n = lua_tonumber(L,-1);
+
+    if (IS_INT64_EQUIVALENT(n)) {
+        mp_encode_lua_integer(L, buf);
+    } else {
+        mp_encode_double(L,buf,(double)n);
+    }
+}
+
+void mp_encode_lua_type(lua_State *L, mp_buf *buf, int level);
+
+/* Convert a lua table into a message pack list. */
+void mp_encode_lua_table_as_array(lua_State *L, mp_buf *buf, int level) {
+#if LUA_VERSION_NUM < 502
+    size_t len = lua_objlen(L,-1), j;
+#else
+    size_t len = lua_rawlen(L,-1), j;
+#endif
+
+    mp_encode_array(L,buf,len);
+    for (j = 1; j <= len; j++) {
+        lua_pushinteger(L,j);
+        lua_gettable(L,-2);
+        mp_encode_lua_type(L,buf,level+1);
+    }
+}
+
+/* Convert a lua table into a message pack key-value map. */
+void mp_encode_lua_table_as_map(lua_State *L, mp_buf *buf, int level) {
+    size_t len = 0;
+
+    /* First step: count keys into table. No other way to do it with the
+     * Lua API, we need to iterate a first time. Note that an alternative
+     * would be to do a single run, and then hack the buffer to insert the
+     * map opcodes for message pack. Too hackish for this lib. */
+    lua_pushnil(L);
+    while(lua_next(L,-2)) {
+        lua_pop(L,1); /* remove value, keep key for next iteration. */
+        len++;
+    }
+
+    /* Step two: actually encoding of the map. */
+    mp_encode_map(L,buf,len);
+    lua_pushnil(L);
+    while(lua_next(L,-2)) {
+        /* Stack: ... key value */
+        lua_pushvalue(L,-2); /* Stack: ... key value key */
+        mp_encode_lua_type(L,buf,level+1); /* encode key */
+        mp_encode_lua_type(L,buf,level+1); /* encode val */
+    }
+}
+
+/* Returns true if the Lua table on top of the stack is exclusively composed
+ * of keys from numerical keys from 1 up to N, with N being the total number
+ * of elements, without any hole in the middle. */
+int table_is_an_array(lua_State *L) {
+    int count = 0, max = 0;
+#if LUA_VERSION_NUM < 503
+    lua_Number n;
+#else
+    lua_Integer n;
+#endif
+
+    /* Stack top on function entry */
+    int stacktop;
+
+    stacktop = lua_gettop(L);
+
+    lua_pushnil(L);
+    while(lua_next(L,-2)) {
+        /* Stack: ... key value */
+        lua_pop(L,1); /* Stack: ... key */
+        /* The <= 0 check is valid here because we're comparing indexes. */
+#if LUA_VERSION_NUM < 503
+        if ((LUA_TNUMBER != lua_type(L,-1)) || (n = lua_tonumber(L, -1)) <= 0 ||
+            !IS_INT_EQUIVALENT(n))
+#else
+        if (!lua_isinteger(L,-1) || (n = lua_tointeger(L, -1)) <= 0)
+#endif
+        {
+            lua_settop(L, stacktop);
+            return 0;
+        }
+        max = (n > max ? n : max);
+        count++;
+    }
+    /* We have the total number of elements in "count". Also we have
+     * the max index encountered in "max". We can't reach this code
+     * if there are indexes <= 0. If you also note that there can not be
+     * repeated keys into a table, you have that if max==count you are sure
+     * that there are all the keys form 1 to count (both included). */
+    lua_settop(L, stacktop);
+    return max == count;
+}
+
+/* If the length operator returns non-zero, that is, there is at least
+ * an object at key '1', we serialize to message pack list. Otherwise
+ * we use a map. */
+void mp_encode_lua_table(lua_State *L, mp_buf *buf, int level) {
+    if (table_is_an_array(L))
+        mp_encode_lua_table_as_array(L,buf,level);
+    else
+        mp_encode_lua_table_as_map(L,buf,level);
+}
+
+void mp_encode_lua_null(lua_State *L, mp_buf *buf) {
+    unsigned char b[1];
+
+    b[0] = 0xc0;
+    mp_buf_append(L,buf,b,1);
+}
+
+void mp_encode_lua_type(lua_State *L, mp_buf *buf, int level) {
+    int t = lua_type(L,-1);
+
+    /* Limit the encoding of nested tables to a specified maximum depth, so that
+     * we survive when called against circular references in tables. */
+    if (t == LUA_TTABLE && level == LUACMSGPACK_MAX_NESTING) t = LUA_TNIL;
+    switch(t) {
+    case LUA_TSTRING: mp_encode_lua_string(L,buf); break;
+    case LUA_TBOOLEAN: mp_encode_lua_bool(L,buf); break;
+    case LUA_TNUMBER:
+    #if LUA_VERSION_NUM < 503
+        mp_encode_lua_number(L,buf); break;
+    #else
+        if (lua_isinteger(L, -1)) {
+            mp_encode_lua_integer(L, buf);
+        } else {
+            mp_encode_lua_number(L, buf);
+        }
+        break;
+    #endif
+    case LUA_TTABLE: mp_encode_lua_table(L,buf,level); break;
+    default: mp_encode_lua_null(L,buf); break;
+    }
+    lua_pop(L,1);
+}
+
+/*
+ * Packs all arguments as a stream for multiple upacking later.
+ * Returns error if no arguments provided.
+ */
+int mp_pack(lua_State *L) {
+    int nargs = lua_gettop(L);
+    int i;
+    mp_buf *buf;
+
+    if (nargs == 0)
+        return luaL_argerror(L, 0, "MessagePack pack needs input.");
+
+    buf = mp_buf_new(L);
+    for(i = 1; i <= nargs; i++) {
+        /* Copy argument i to top of stack for _encode processing;
+         * the encode function pops it from the stack when complete. */
+        lua_pushvalue(L, i);
+
+        mp_encode_lua_type(L,buf,0);
+
+        lua_pushlstring(L,(char*)buf->b,buf->len);
+
+        /* Reuse the buffer for the next operation by
+         * setting its free count to the total buffer size
+         * and the current position to zero. */
+        buf->free += buf->len;
+        buf->len = 0;
+    }
+    mp_buf_free(L, buf);
+
+    /* Concatenate all nargs buffers together */
+    lua_concat(L, nargs);
+    return 1;
+}
+
+/* ------------------------------- Decoding --------------------------------- */
+
+void mp_decode_to_lua_type(lua_State *L, mp_cur *c);
+
+void mp_decode_to_lua_array(lua_State *L, mp_cur *c, size_t len) {
+    assert(len <= UINT_MAX);
+    int index = 1;
+
+    lua_newtable(L);
+    while(len--) {
+        lua_pushunsigned(L,index++);
+        mp_decode_to_lua_type(L,c);
+        if (c->err) return;
+        lua_settable(L,-3);
+    }
+}
+
+void mp_decode_to_lua_hash(lua_State *L, mp_cur *c, size_t len) {
+    assert(len <= UINT_MAX);
+    lua_newtable(L);
+    while(len--) {
+        mp_decode_to_lua_type(L,c); /* key */
+        if (c->err) return;
+        mp_decode_to_lua_type(L,c); /* value */
+        if (c->err) return;
+        lua_settable(L,-3);
+    }
+}
+
+/* Decode a Message Pack raw object pointed by the string cursor 'c' to
+ * a Lua type, that is left as the only result on the stack. */
+void mp_decode_to_lua_type(lua_State *L, mp_cur *c) {
+    mp_cur_need(c,1);
+
+    /* If we return more than 18 elements, we must resize the stack to
+     * fit all our return values.  But, there is no way to
+     * determine how many objects a msgpack will unpack to up front, so
+     * we request a +1 larger stack on each iteration (noop if stack is
+     * big enough, and when stack does require resize it doubles in size) */
+    luaL_checkstack(L, 1,
+        "too many return values at once; "
+        "use unpack_one or unpack_limit instead.");
+
+    switch(c->p[0]) {
+    case 0xcc:  /* uint 8 */
+        mp_cur_need(c,2);
+        lua_pushunsigned(L,c->p[1]);
+        mp_cur_consume(c,2);
+        break;
+    case 0xd0:  /* int 8 */
+        mp_cur_need(c,2);
+        lua_pushinteger(L,(signed char)c->p[1]);
+        mp_cur_consume(c,2);
+        break;
+    case 0xcd:  /* uint 16 */
+        mp_cur_need(c,3);
+        lua_pushunsigned(L,
+            (c->p[1] << 8) |
+             c->p[2]);
+        mp_cur_consume(c,3);
+        break;
+    case 0xd1:  /* int 16 */
+        mp_cur_need(c,3);
+        lua_pushinteger(L,(int16_t)
+            (c->p[1] << 8) |
+             c->p[2]);
+        mp_cur_consume(c,3);
+        break;
+    case 0xce:  /* uint 32 */
+        mp_cur_need(c,5);
+        lua_pushunsigned(L,
+            ((uint32_t)c->p[1] << 24) |
+            ((uint32_t)c->p[2] << 16) |
+            ((uint32_t)c->p[3] << 8) |
+             (uint32_t)c->p[4]);
+        mp_cur_consume(c,5);
+        break;
+    case 0xd2:  /* int 32 */
+        mp_cur_need(c,5);
+        lua_pushinteger(L,
+            ((int32_t)c->p[1] << 24) |
+            ((int32_t)c->p[2] << 16) |
+            ((int32_t)c->p[3] << 8) |
+             (int32_t)c->p[4]);
+        mp_cur_consume(c,5);
+        break;
+    case 0xcf:  /* uint 64 */
+        mp_cur_need(c,9);
+        lua_pushunsigned(L,
+            ((uint64_t)c->p[1] << 56) |
+            ((uint64_t)c->p[2] << 48) |
+            ((uint64_t)c->p[3] << 40) |
+            ((uint64_t)c->p[4] << 32) |
+            ((uint64_t)c->p[5] << 24) |
+            ((uint64_t)c->p[6] << 16) |
+            ((uint64_t)c->p[7] << 8) |
+             (uint64_t)c->p[8]);
+        mp_cur_consume(c,9);
+        break;
+    case 0xd3:  /* int 64 */
+        mp_cur_need(c,9);
+#if LUA_VERSION_NUM < 503
+        lua_pushnumber(L,
+#else
+        lua_pushinteger(L,
+#endif
+            ((int64_t)c->p[1] << 56) |
+            ((int64_t)c->p[2] << 48) |
+            ((int64_t)c->p[3] << 40) |
+            ((int64_t)c->p[4] << 32) |
+            ((int64_t)c->p[5] << 24) |
+            ((int64_t)c->p[6] << 16) |
+            ((int64_t)c->p[7] << 8) |
+             (int64_t)c->p[8]);
+        mp_cur_consume(c,9);
+        break;
+    case 0xc0:  /* nil */
+        lua_pushnil(L);
+        mp_cur_consume(c,1);
+        break;
+    case 0xc3:  /* true */
+        lua_pushboolean(L,1);
+        mp_cur_consume(c,1);
+        break;
+    case 0xc2:  /* false */
+        lua_pushboolean(L,0);
+        mp_cur_consume(c,1);
+        break;
+    case 0xca:  /* float */
+        mp_cur_need(c,5);
+        assert(sizeof(float) == 4);
+        {
+            float f;
+            memcpy(&f,c->p+1,4);
+            memrevifle(&f,4);
+            lua_pushnumber(L,f);
+            mp_cur_consume(c,5);
+        }
+        break;
+    case 0xcb:  /* double */
+        mp_cur_need(c,9);
+        assert(sizeof(double) == 8);
+        {
+            double d;
+            memcpy(&d,c->p+1,8);
+            memrevifle(&d,8);
+            lua_pushnumber(L,d);
+            mp_cur_consume(c,9);
+        }
+        break;
+    case 0xd9:  /* raw 8 */
+        mp_cur_need(c,2);
+        {
+            size_t l = c->p[1];
+            mp_cur_need(c,2+l);
+            lua_pushlstring(L,(char*)c->p+2,l);
+            mp_cur_consume(c,2+l);
+        }
+        break;
+    case 0xda:  /* raw 16 */
+        mp_cur_need(c,3);
+        {
+            size_t l = (c->p[1] << 8) | c->p[2];
+            mp_cur_need(c,3+l);
+            lua_pushlstring(L,(char*)c->p+3,l);
+            mp_cur_consume(c,3+l);
+        }
+        break;
+    case 0xdb:  /* raw 32 */
+        mp_cur_need(c,5);
+        {
+            size_t l = ((size_t)c->p[1] << 24) |
+                       ((size_t)c->p[2] << 16) |
+                       ((size_t)c->p[3] << 8) |
+                       (size_t)c->p[4];
+            mp_cur_consume(c,5);
+            mp_cur_need(c,l);
+            lua_pushlstring(L,(char*)c->p,l);
+            mp_cur_consume(c,l);
+        }
+        break;
+    case 0xdc:  /* array 16 */
+        mp_cur_need(c,3);
+        {
+            size_t l = (c->p[1] << 8) | c->p[2];
+            mp_cur_consume(c,3);
+            mp_decode_to_lua_array(L,c,l);
+        }
+        break;
+    case 0xdd:  /* array 32 */
+        mp_cur_need(c,5);
+        {
+            size_t l = ((size_t)c->p[1] << 24) |
+                       ((size_t)c->p[2] << 16) |
+                       ((size_t)c->p[3] << 8) |
+                       (size_t)c->p[4];
+            mp_cur_consume(c,5);
+            mp_decode_to_lua_array(L,c,l);
+        }
+        break;
+    case 0xde:  /* map 16 */
+        mp_cur_need(c,3);
+        {
+            size_t l = (c->p[1] << 8) | c->p[2];
+            mp_cur_consume(c,3);
+            mp_decode_to_lua_hash(L,c,l);
+        }
+        break;
+    case 0xdf:  /* map 32 */
+        mp_cur_need(c,5);
+        {
+            size_t l = ((size_t)c->p[1] << 24) |
+                       ((size_t)c->p[2] << 16) |
+                       ((size_t)c->p[3] << 8) |
+                       (size_t)c->p[4];
+            mp_cur_consume(c,5);
+            mp_decode_to_lua_hash(L,c,l);
+        }
+        break;
+    default:    /* types that can't be idenitified by first byte value. */
+        if ((c->p[0] & 0x80) == 0) {   /* positive fixnum */
+            lua_pushunsigned(L,c->p[0]);
+            mp_cur_consume(c,1);
+        } else if ((c->p[0] & 0xe0) == 0xe0) {  /* negative fixnum */
+            lua_pushinteger(L,(signed char)c->p[0]);
+            mp_cur_consume(c,1);
+        } else if ((c->p[0] & 0xe0) == 0xa0) {  /* fix raw */
+            size_t l = c->p[0] & 0x1f;
+            mp_cur_need(c,1+l);
+            lua_pushlstring(L,(char*)c->p+1,l);
+            mp_cur_consume(c,1+l);
+        } else if ((c->p[0] & 0xf0) == 0x90) {  /* fix map */
+            size_t l = c->p[0] & 0xf;
+            mp_cur_consume(c,1);
+            mp_decode_to_lua_array(L,c,l);
+        } else if ((c->p[0] & 0xf0) == 0x80) {  /* fix map */
+            size_t l = c->p[0] & 0xf;
+            mp_cur_consume(c,1);
+            mp_decode_to_lua_hash(L,c,l);
+        } else {
+            c->err = MP_CUR_ERROR_BADFMT;
+        }
+    }
+}
+
+int mp_unpack_full(lua_State *L, int limit, int offset) {
+    size_t len;
+    const char *s;
+    mp_cur c;
+    int cnt; /* Number of objects unpacked */
+    int decode_all = (!limit && !offset);
+
+    s = luaL_checklstring(L,1,&len); /* if no match, exits */
+
+    if (offset < 0 || limit < 0) /* requesting negative off or lim is invalid */
+        return luaL_error(L,
+            "Invalid request to unpack with offset of %d and limit of %d.",
+            offset, len);
+    else if ((size_t)offset > len)
+        return luaL_error(L,
+            "Start offset %d greater than input length %d.", offset, len);
+
+    if (decode_all) limit = INT_MAX;
+
+    mp_cur_init(&c,(const unsigned char *)s+offset,len-offset);
+
+    /* We loop over the decode because this could be a stream
+     * of multiple top-level values serialized together */
+    for(cnt = 0; c.left > 0 && cnt < limit; cnt++) {
+        mp_decode_to_lua_type(L,&c);
+
+        if (c.err == MP_CUR_ERROR_EOF) {
+            return luaL_error(L,"Missing bytes in input.");
+        } else if (c.err == MP_CUR_ERROR_BADFMT) {
+            return luaL_error(L,"Bad data format in input.");
+        }
+    }
+
+    if (!decode_all) {
+        /* c->left is the remaining size of the input buffer.
+         * subtract the entire buffer size from the unprocessed size
+         * to get our next start offset */
+        int offset = len - c.left;
+        /* Return offset -1 when we have have processed the entire buffer. */
+        lua_pushinteger(L, c.left == 0 ? -1 : offset);
+        /* Results are returned with the arg elements still
+         * in place. Lua takes care of only returning
+         * elements above the args for us.
+         * In this case, we have one arg on the stack
+         * for this function, so we insert our first return
+         * value at position 2. */
+        lua_insert(L, 2);
+        cnt += 1; /* increase return count by one to make room for offset */
+    }
+
+    return cnt;
+}
+
+int mp_unpack(lua_State *L) {
+    return mp_unpack_full(L, 0, 0);
+}
+
+int mp_unpack_one(lua_State *L) {
+    int offset = luaL_optinteger(L, 2, 0);
+    /* Variable pop because offset may not exist */
+    lua_pop(L, lua_gettop(L)-1);
+    return mp_unpack_full(L, 1, offset);
+}
+
+int mp_unpack_limit(lua_State *L) {
+    int limit = luaL_checkinteger(L, 2);
+    int offset = luaL_optinteger(L, 3, 0);
+    /* Variable pop because offset may not exist */
+    lua_pop(L, lua_gettop(L)-1);
+
+    return mp_unpack_full(L, limit, offset);
+}
+
+int mp_safe(lua_State *L) {
+    int argc, err, total_results;
+
+    argc = lua_gettop(L);
+
+    /* This adds our function to the bottom of the stack
+     * (the "call this function" position) */
+    lua_pushvalue(L, lua_upvalueindex(1));
+    lua_insert(L, 1);
+
+    err = lua_pcall(L, argc, LUA_MULTRET, 0);
+    total_results = lua_gettop(L);
+
+    if (!err) {
+        return total_results;
+    } else {
+        lua_pushnil(L);
+        lua_insert(L,-2);
+        return 2;
+    }
+}
+
+/* -------------------------------------------------------------------------- */
+const struct luaL_Reg cmds[] = {
+    {"pack", mp_pack},
+    {"unpack", mp_unpack},
+    {"unpack_one", mp_unpack_one},
+    {"unpack_limit", mp_unpack_limit},
+    {0}
+};
+
+int luaopen_create(lua_State *L) {
+    size_t i;
+    /* Manually construct our module table instead of
+     * relying on _register or _newlib */
+    lua_newtable(L);
+
+    for (i = 0; i < (sizeof(cmds)/sizeof(*cmds) - 1); i++) {
+        lua_pushcfunction(L, cmds[i].func);
+        lua_setfield(L, -2, cmds[i].name);
+    }
+
+    /* Add metadata */
+    lua_pushliteral(L, LUACMSGPACK_NAME);
+    lua_setfield(L, -2, "_NAME");
+    lua_pushliteral(L, LUACMSGPACK_VERSION);
+    lua_setfield(L, -2, "_VERSION");
+    lua_pushliteral(L, LUACMSGPACK_COPYRIGHT);
+    lua_setfield(L, -2, "_COPYRIGHT");
+    lua_pushliteral(L, LUACMSGPACK_DESCRIPTION);
+    lua_setfield(L, -2, "_DESCRIPTION");
+    return 1;
+}
+
+LUALIB_API int luaopen_cmsgpack(lua_State *L) {
+    luaopen_create(L);
+
+#if LUA_VERSION_NUM < 502
+    /* Register name globally for 5.1 */
+    lua_pushvalue(L, -1);
+    lua_setglobal(L, LUACMSGPACK_NAME);
+#endif
+
+    return 1;
+}
+
+LUALIB_API int luaopen_cmsgpack_safe(lua_State *L) {
+    size_t i;
+
+    luaopen_cmsgpack(L);
+
+    /* Wrap all functions in the safe handler */
+    for (i = 0; i < (sizeof(cmds)/sizeof(*cmds) - 1); i++) {
+        lua_getfield(L, -1, cmds[i].name);
+        lua_pushcclosure(L, mp_safe, 1);
+        lua_setfield(L, -2, cmds[i].name);
+    }
+
+#if LUA_VERSION_NUM < 502
+    /* Register name globally for 5.1 */
+    lua_pushvalue(L, -1);
+    lua_setglobal(L, LUACMSGPACK_SAFE_NAME);
+#endif
+
+    return 1;
+}
+
+/******************************************************************************
+* Copyright (C) 2012 Salvatore Sanfilippo.  All rights reserved.
+*
+* Permission is hereby granted, free of charge, to any person obtaining
+* a copy of this software and associated documentation files (the
+* "Software"), to deal in the Software without restriction, including
+* without limitation the rights to use, copy, modify, merge, publish,
+* distribute, sublicense, and/or sell copies of the Software, and to
+* permit persons to whom the Software is furnished to do so, subject to
+* the following conditions:
+*
+* The above copyright notice and this permission notice shall be
+* included in all copies or substantial portions of the Software.
+*
+* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+******************************************************************************/
diff --git a/src/sysbin/lx/lxinit.c b/src/sysbin/lx/lxinit.c
index c0059c7..c185b45 100644
--- a/src/sysbin/lx/lxinit.c
+++ b/src/sysbin/lx/lxinit.c
@@ -34,6 +34,7 @@
 
 static const luaL_Reg loadedlibs[] = {
   {LX_SYSLIBNAME, lx_open_sys},
+  {LX_MSGLIBNAME, lx_open_msg},
   {NULL, NULL}
 };
 
diff --git a/src/sysbin/lx/lxlib.h b/src/sysbin/lx/lxlib.h
index e65ab6f..199c78d 100644
--- a/src/sysbin/lx/lxlib.h
+++ b/src/sysbin/lx/lxlib.h
@@ -9,6 +9,12 @@
 #define LX_SYSLIBNAME "lx.sys"
 LUAMOD_API int (lx_open_sys) (lua_State *L);
 
+#define LX_SYSLIBNAME "lx.sys"
+LUAMOD_API int (lx_open_sys) (lua_State *L);
+
+#define LX_MSGLIBNAME "lx.msg"
+LUAMOD_API int (luaopen_cmsgpack) (lua_State *L);
+#define lx_open_msg luaopen_cmsgpack
 
 /* open all previous libraries */
 LUALIB_API void (lx_openlibs) (lua_State *L);
diff --git a/src/sysbin/lx/lxsyslib.c b/src/sysbin/lx/lxsyslib.c
index fbafde9..52c6978 100644
--- a/src/sysbin/lx/lxsyslib.c
+++ b/src/sysbin/lx/lxsyslib.c
@@ -191,8 +191,45 @@ static int sys_fctl(lua_State *L) {
 }
 
 static int sys_select(lua_State *L) {
-  // TODO
-  return 0;
+  luaL_checktype(L, 1, LUA_TTABLE);
+  int nfds = luaL_len(L, 1);
+  int timeout;
+  if (lua_isinteger(L, 2)) {
+    timeout = luaL_checkinteger(L, 2);
+  } else {
+    timeout = 0;
+  }
+
+  sel_fd_t *fds = (sel_fd_t*)malloc(nfds*sizeof(sel_fd_t));
+  if (fds == NULL)
+    luaL_error(L, "Out of memory, could not allocate %d sel_fd_t", nfds);
+
+  for (int i = 0; i < nfds; i++) {
+    lua_rawgeti(L, 1, i+1);
+    luaL_checktype(L, -1, LUA_TTABLE);
+
+    lua_rawgeti(L, -1, 1);
+    fds[i].fd = luaL_checkinteger(L, -1);
+    lua_pop(L, 1);
+    
+    lua_rawgeti(L, -1, 2);
+    fds[i].req_flags = luaL_checkinteger(L, -1);
+    lua_pop(L, 2);
+  }
+
+  bool result = sc_select(fds, nfds, timeout);
+
+  for (int i = 0; i < nfds; i++) {
+    lua_rawgeti(L, 1, i+1);
+    lua_pushinteger(L, fds[i].got_flags);
+    lua_rawseti(L, -2, 3);
+    lua_pop(L, 1);
+  }
+
+  free(fds);
+
+  lua_pushboolean(L, result);
+  return 1;
 }
 
 static int sys_make_channel(lua_State *L) {
diff --git a/src/syslua/lx/lxinit.lua b/src/syslua/lx/lxinit.lua
index 1c8d116..055ffc9 100644
--- a/src/syslua/lx/lxinit.lua
+++ b/src/syslua/lx/lxinit.lua
@@ -38,3 +38,27 @@ function string.split(str, sep)
    str:gsub(pattern, function(c) fields[#fields+1] = c end)
    return fields
 end
+
+function hexdump(str)
+	for i = 1, #str, 16 do
+		local b = {string.byte(str, i, math.min(i+15, #str))}
+		local s = ""
+		for j = 1, 16 do
+			if b[j] then
+				s = s .. string.format("%02x ", b[j])
+			else
+				s = s .. '   '
+			end
+		end
+		s = s .. '|  '
+		for j = 1, #b do
+			ss = string.char(b[j])
+			if b[j] >= 32 and b[j] < 128 then
+				s = s .. string.char(b[j])
+			else
+				s = s .. '.'
+			end
+		end
+		print(s)
+	end
+end