support datagram unix domain sockets

1 files changed, 388 insertions, 0 deletions

diff --git a/src/unixudp.c b/src/unixudp.c
new file mode 100644
index 0000000..ec348cf
--- /dev/null
+++ b/src/unixudp.c
@@ -0,0 +1,388 @@
+/*=========================================================================*\
+* Unix domain socket udp submodule
+* LuaSocket toolkit
+\*=========================================================================*/
+#include <string.h>
+#include <stdlib.h>
+
+#include "lua.h"
+#include "lauxlib.h"
+
+#include "auxiliar.h"
+#include "socket.h"
+#include "options.h"
+#include "unix.h"
+#include <sys/un.h>
+
+#define UNIXUDP_DATAGRAMSIZE 8192
+
+/*=========================================================================*\
+* Internal function prototypes
+\*=========================================================================*/
+static int global_create(lua_State *L);
+static int meth_connect(lua_State *L);
+static int meth_bind(lua_State *L);
+static int meth_send(lua_State *L);
+static int meth_receive(lua_State *L);
+static int meth_close(lua_State *L);
+static int meth_setoption(lua_State *L);
+static int meth_settimeout(lua_State *L);
+static int meth_gettimeout(lua_State *L);
+static int meth_getfd(lua_State *L);
+static int meth_setfd(lua_State *L);
+static int meth_dirty(lua_State *L);
+static int meth_receivefrom(lua_State *L);
+static int meth_sendto(lua_State *L);
+
+static const char *unixudp_tryconnect(p_unix un, const char *path);
+static const char *unixudp_trybind(p_unix un, const char *path);
+
+/* unixudp object methods */
+static luaL_Reg unixudp_methods[] = {
+    {"__gc",        meth_close},
+    {"__tostring",  auxiliar_tostring},
+    {"bind",        meth_bind},
+    {"close",       meth_close},
+    {"connect",     meth_connect},
+    {"dirty",       meth_dirty},
+    {"getfd",       meth_getfd},
+    {"send",        meth_send},
+    {"sendto",      meth_sendto},
+    {"receive",     meth_receive},
+    {"receivefrom", meth_receivefrom},
+    {"setfd",       meth_setfd},
+    {"setoption",   meth_setoption},
+    {"setpeername", meth_connect},
+    {"setsockname", meth_bind},
+    {"settimeout",  meth_settimeout},
+    {"gettimeout",  meth_gettimeout},
+    {NULL,          NULL}
+};
+
+/* socket option handlers */
+static t_opt optset[] = {
+    {"reuseaddr",   opt_set_reuseaddr},
+    {NULL,          NULL}
+};
+
+/* functions in library namespace */
+static luaL_Reg func[] = {
+    {"udp", global_create},
+    {NULL, NULL}
+};
+
+/*-------------------------------------------------------------------------*\
+* Initializes module
+\*-------------------------------------------------------------------------*/
+int unixudp_open(lua_State *L)
+{
+    /* create classes */
+    auxiliar_newclass(L, "unixudp{connected}", unixudp_methods);
+    auxiliar_newclass(L, "unixudp{unconnected}", unixudp_methods);
+    /* create class groups */
+    auxiliar_add2group(L, "unixudp{connected}",   "unixudp{any}");
+    auxiliar_add2group(L, "unixudp{unconnected}", "unixudp{any}");
+    auxiliar_add2group(L, "unixudp{connected}",   "select{able}");
+    auxiliar_add2group(L, "unixudp{unconnected}", "select{able}");
+
+    luaL_setfuncs(L, func, 0);
+    return 1;
+}
+
+/*=========================================================================*\
+* Lua methods
+\*=========================================================================*/
+static const char *unixudp_strerror(int err)
+{
+    /* a 'closed' error on an unconnected means the target address was not
+     * accepted by the transport layer */
+    if (err == IO_CLOSED) return "refused";
+    else return socket_strerror(err);
+}
+
+static int meth_send(lua_State *L)
+{
+    p_unix un = (p_unix) auxiliar_checkclass(L, "unixudp{connected}", 1);
+    p_timeout tm = &un->tm;
+    size_t count, sent = 0;
+    int err;
+    const char *data = luaL_checklstring(L, 2, &count);
+    timeout_markstart(tm);
+    err = socket_send(&un->sock, data, count, &sent, tm);
+    if (err != IO_DONE) {
+        lua_pushnil(L);
+        lua_pushstring(L, unixudp_strerror(err));
+        return 2;
+    }
+    lua_pushnumber(L, (lua_Number) sent);
+    return 1;
+}
+
+/*-------------------------------------------------------------------------*\
+* Send data through unconnected unixudp socket
+\*-------------------------------------------------------------------------*/
+static int meth_sendto(lua_State *L)
+{
+    p_unix un = (p_unix) auxiliar_checkclass(L, "unixudp{unconnected}", 1);
+    size_t count, sent = 0;
+    const char *data = luaL_checklstring(L, 2, &count);
+    const char *path = luaL_checkstring(L, 3);
+    p_timeout tm = &un->tm;
+    int err;
+    struct sockaddr_un remote;
+    size_t len = strlen(path);
+
+    if (len >= sizeof(remote.sun_path)) {
+                lua_pushnil(L);
+                lua_pushstring(L, "path too long");
+                return 2;
+        }
+
+    memset(&remote, 0, sizeof(remote));
+    strcpy(remote.sun_path, path);
+    remote.sun_family = AF_UNIX;
+    timeout_markstart(tm);
+#ifdef UNIX_HAS_SUN_LEN
+    remote.sun_len = sizeof(remote.sun_family) + sizeof(remote.sun_len)
+        + len + 1;
+    err = socket_sendto(&un->sock, data, count, &sent, (SA *) &remote, remote.sun_len, tm);
+#else
+    err = socket_sendto(&un->sock, data, count, &sent, (SA *) &remote,
+                        sizeof(remote.sun_family) + len, tm);
+#endif
+    if (err != IO_DONE) {
+        lua_pushnil(L);
+        lua_pushstring(L, unixudp_strerror(err));
+        return 2;
+    }
+    lua_pushnumber(L, (lua_Number) sent);
+    return 1;
+}
+
+static int meth_receive(lua_State *L) {
+    p_unix un = (p_unix) auxiliar_checkclass(L, "unixudp{any}", 1);
+    char buf[UNIXUDP_DATAGRAMSIZE];
+    size_t got, wanted = (size_t) luaL_optnumber(L, 2, sizeof(buf));
+    char *dgram = wanted > sizeof(buf)? (char *) malloc(wanted): buf;
+    int err;
+    p_timeout tm = &un->tm;
+    timeout_markstart(tm);
+    if (!dgram) {
+        lua_pushnil(L);
+        lua_pushliteral(L, "out of memory");
+        return 2;
+    }
+    err = socket_recv(&un->sock, dgram, wanted, &got, tm);
+    /* Unlike TCP, recv() of zero is not closed, but a zero-length packet. */
+    if (err != IO_DONE && err != IO_CLOSED) {
+        lua_pushnil(L);
+        lua_pushstring(L, unixudp_strerror(err));
+        if (wanted > sizeof(buf)) free(dgram);
+        return 2;
+    }
+    lua_pushlstring(L, dgram, got);
+    if (wanted > sizeof(buf)) free(dgram);
+    return 1;
+}
+
+/*-------------------------------------------------------------------------*\
+* Receives data and sender from a UDP socket
+\*-------------------------------------------------------------------------*/
+static int meth_receivefrom(lua_State *L) {
+    p_unix un = (p_unix) auxiliar_checkclass(L, "unixudp{unconnected}", 1);
+    char buf[UNIXUDP_DATAGRAMSIZE];
+    size_t got, wanted = (size_t) luaL_optnumber(L, 2, sizeof(buf));
+    char *dgram = wanted > sizeof(buf)? (char *) malloc(wanted): buf;
+    struct sockaddr_un addr;
+    socklen_t addr_len = sizeof(addr);
+    int err;
+    p_timeout tm = &un->tm;
+    timeout_markstart(tm);
+    if (!dgram) {
+        lua_pushnil(L);
+        lua_pushliteral(L, "out of memory");
+        return 2;
+    }
+    err = socket_recvfrom(&un->sock, dgram, wanted, &got, (SA *) &addr,
+            &addr_len, tm);
+    /* Unlike TCP, recv() of zero is not closed, but a zero-length packet. */
+    if (err != IO_DONE && err != IO_CLOSED) {
+        lua_pushnil(L);
+        lua_pushstring(L, unixudp_strerror(err));
+        if (wanted > sizeof(buf)) free(dgram);
+        return 2;
+    }
+
+    lua_pushlstring(L, dgram, got);
+        /* the path may be empty, when client send without bind */
+    lua_pushstring(L, addr.sun_path);
+    if (wanted > sizeof(buf)) free(dgram);
+    return 2;
+}
+
+/*-------------------------------------------------------------------------*\
+* Just call option handler
+\*-------------------------------------------------------------------------*/
+static int meth_setoption(lua_State *L) {
+    p_unix un = (p_unix) auxiliar_checkgroup(L, "unixudp{any}", 1);
+    return opt_meth_setoption(L, optset, &un->sock);
+}
+
+/*-------------------------------------------------------------------------*\
+* Select support methods
+\*-------------------------------------------------------------------------*/
+static int meth_getfd(lua_State *L) {
+    p_unix un = (p_unix) auxiliar_checkgroup(L, "unixudp{any}", 1);
+    lua_pushnumber(L, (int) un->sock);
+    return 1;
+}
+
+/* this is very dangerous, but can be handy for those that are brave enough */
+static int meth_setfd(lua_State *L) {
+    p_unix un = (p_unix) auxiliar_checkgroup(L, "unixudp{any}", 1);
+    un->sock = (t_socket) luaL_checknumber(L, 2);
+    return 0;
+}
+
+static int meth_dirty(lua_State *L) {
+    p_unix un = (p_unix) auxiliar_checkgroup(L, "unixudp{any}", 1);
+    (void) un;
+    lua_pushboolean(L, 0);
+    return 1;
+}
+
+/*-------------------------------------------------------------------------*\
+* Binds an object to an address
+\*-------------------------------------------------------------------------*/
+static const char *unixudp_trybind(p_unix un, const char *path) {
+    struct sockaddr_un local;
+    size_t len = strlen(path);
+    int err;
+    if (len >= sizeof(local.sun_path)) return "path too long";
+    memset(&local, 0, sizeof(local));
+    strcpy(local.sun_path, path);
+    local.sun_family = AF_UNIX;
+#ifdef UNIX_HAS_SUN_LEN
+    local.sun_len = sizeof(local.sun_family) + sizeof(local.sun_len)
+        + len + 1;
+    err = socket_bind(&un->sock, (SA *) &local, local.sun_len);
+
+#else
+    err = socket_bind(&un->sock, (SA *) &local,
+            sizeof(local.sun_family) + len);
+#endif
+    if (err != IO_DONE) socket_destroy(&un->sock);
+    return socket_strerror(err);
+}
+
+static int meth_bind(lua_State *L)
+{
+    p_unix un = (p_unix) auxiliar_checkclass(L, "unixudp{unconnected}", 1);
+    const char *path =  luaL_checkstring(L, 2);
+    const char *err = unixudp_trybind(un, path);
+    if (err) {
+        lua_pushnil(L);
+        lua_pushstring(L, err);
+        return 2;
+    }
+    lua_pushnumber(L, 1);
+    return 1;
+}
+
+/*-------------------------------------------------------------------------*\
+* Turns a master unixudp object into a client object.
+\*-------------------------------------------------------------------------*/
+static const char *unixudp_tryconnect(p_unix un, const char *path)
+{
+    struct sockaddr_un remote;
+    int err;
+    size_t len = strlen(path);
+    if (len >= sizeof(remote.sun_path)) return "path too long";
+    memset(&remote, 0, sizeof(remote));
+    strcpy(remote.sun_path, path);
+    remote.sun_family = AF_UNIX;
+    timeout_markstart(&un->tm);
+#ifdef UNIX_HAS_SUN_LEN
+    remote.sun_len = sizeof(remote.sun_family) + sizeof(remote.sun_len)
+        + len + 1;
+    err = socket_connect(&un->sock, (SA *) &remote, remote.sun_len, &un->tm);
+#else
+    err = socket_connect(&un->sock, (SA *) &remote,
+            sizeof(remote.sun_family) + len, &un->tm);
+#endif
+    if (err != IO_DONE) socket_destroy(&un->sock);
+    return socket_strerror(err);
+}
+
+static int meth_connect(lua_State *L)
+{
+    p_unix un = (p_unix) auxiliar_checkclass(L, "unixudp{any}", 1);
+    const char *path =  luaL_checkstring(L, 2);
+    const char *err = unixudp_tryconnect(un, path);
+    if (err) {
+        lua_pushnil(L);
+        lua_pushstring(L, err);
+        return 2;
+    }
+    /* turn unconnected object into a connected object */
+    auxiliar_setclass(L, "unixudp{connected}", 1);
+    lua_pushnumber(L, 1);
+    return 1;
+}
+
+/*-------------------------------------------------------------------------*\
+* Closes socket used by object
+\*-------------------------------------------------------------------------*/
+static int meth_close(lua_State *L)
+{
+    p_unix un = (p_unix) auxiliar_checkgroup(L, "unixudp{any}", 1);
+    socket_destroy(&un->sock);
+    lua_pushnumber(L, 1);
+    return 1;
+}
+
+/*-------------------------------------------------------------------------*\
+* Just call tm methods
+\*-------------------------------------------------------------------------*/
+static int meth_settimeout(lua_State *L)
+{
+    p_unix un = (p_unix) auxiliar_checkgroup(L, "unixudp{any}", 1);
+    return timeout_meth_settimeout(L, &un->tm);
+}
+
+static int meth_gettimeout(lua_State *L)
+{
+    p_unix un = (p_unix) auxiliar_checkgroup(L, "unixudp{any}", 1);
+    return timeout_meth_gettimeout(L, &un->tm);
+}
+
+/*=========================================================================*\
+* Library functions
+\*=========================================================================*/
+/*-------------------------------------------------------------------------*\
+* Creates a master unixudp object
+\*-------------------------------------------------------------------------*/
+static int global_create(lua_State *L)
+{
+    t_socket sock;
+    int err = socket_create(&sock, AF_UNIX, SOCK_DGRAM, 0);
+    /* try to allocate a system socket */
+    if (err == IO_DONE) {
+        /* allocate unixudp object */
+        p_unix un = (p_unix) lua_newuserdata(L, sizeof(t_unix));
+        /* set its type as master object */
+        auxiliar_setclass(L, "unixudp{unconnected}", -1);
+        /* initialize remaining structure fields */
+        socket_setnonblocking(&sock);
+        un->sock = sock;
+        io_init(&un->io, (p_send) socket_send, (p_recv) socket_recv,
+                (p_error) socket_ioerror, &un->sock);
+        timeout_init(&un->tm, -1, -1);
+        buffer_init(&un->buf, &un->io, &un->tm);
+        return 1;
+    } else {
+        lua_pushnil(L);
+        lua_pushstring(L, socket_strerror(err));
+        return 2;
+    }
+}