From c4378784ae2caec57634f9f04bcb3dcddc673f36 Mon Sep 17 00:00:00 2001 From: Rick Lei Date: Wed, 14 Jan 2015 22:11:43 +0800 Subject: Add Android 4.1+ support. See doc/README-Android.md for build HOWTO. * Update CMake files to work with android-cmake * Use unix domain socket for communicating with Android GUI * May also run standalone but requires rooted Android device --- src/CMakeLists.txt | 1 + src/android_ctrl_sock.c | 218 ++++++++++++++++++++++++++++++++++++++++++++++++ src/compat.h | 2 +- src/config.c | 10 +++ src/cpuid.h | 2 +- src/fastd.c | 24 ++++-- src/fastd.h | 18 ++++ src/options.c | 11 +++ src/options.def.h | 5 ++ src/poll.c | 2 +- src/send.c | 9 ++ src/socket.c | 7 ++ src/tuntap.c | 50 +++++++++-- 13 files changed, 342 insertions(+), 17 deletions(-) create mode 100644 src/android_ctrl_sock.c (limited to 'src') diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt index 978d8e9..e7dd5d1 100644 --- a/src/CMakeLists.txt +++ b/src/CMakeLists.txt @@ -18,6 +18,7 @@ configure_file(${CMAKE_CURRENT_SOURCE_DIR}/fastd_config.h.in ${CMAKE_CURRENT_BIN BISON_TARGET(fastd_config_parse config.y ${CMAKE_CURRENT_BINARY_DIR}/config.yy.c) add_executable(fastd + android_ctrl_sock.c async.c capabilities.c config.c diff --git a/src/android_ctrl_sock.c b/src/android_ctrl_sock.c new file mode 100644 index 0000000..c681755 --- /dev/null +++ b/src/android_ctrl_sock.c @@ -0,0 +1,218 @@ +/*************************************************************************** + * libancillary - black magic on Unix domain sockets + * (C) Nicolas George + ***************************************************************************/ + +/* + * fastd Android port + * Copyright (c) 2014-2015, Haofeng "Rick" Lei + * All rights reserved. + */ + +/* + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO + * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; + * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, + * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR + * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF + * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/* libancillary code from: + * http://www.normalesup.org/~george/comp/libancillary/ + * with minor indent/style adjusts to fit fastd project + */ +/* vim: set noexpandtab ts=8 sw=8 sts=8 */ + +/** + \file + + Android specific methods for communicating with GUI +*/ + +#ifdef __ANDROID__ + +#include +#include +#include +#include + +#include "fastd.h" + +/** declare a work buffer for sending/receiving \e n handles */ +#define ANCIL_FD_BUFFER(n) \ + struct { \ + struct cmsghdr h; \ + int fd[n]; \ + } + +/** receive \e n_fds handles from unix domain socket \e sock and store in \e fds */ +static int ancil_recv_fds_with_buffer(int sock, int *fds, unsigned n_fds, void *buffer) { + struct msghdr msghdr; + char nothing; + struct iovec nothing_ptr; + struct cmsghdr *cmsg; + int i; + + nothing_ptr.iov_base = ¬hing; + nothing_ptr.iov_len = 1; + msghdr.msg_name = NULL; + msghdr.msg_namelen = 0; + msghdr.msg_iov = ¬hing_ptr; + msghdr.msg_iovlen = 1; + msghdr.msg_flags = 0; + msghdr.msg_control = buffer; + msghdr.msg_controllen = sizeof(struct cmsghdr) + sizeof(int) * n_fds; + cmsg = CMSG_FIRSTHDR(&msghdr); + cmsg->cmsg_len = msghdr.msg_controllen; + cmsg->cmsg_level = SOL_SOCKET; + cmsg->cmsg_type = SCM_RIGHTS; + for (i = 0; i < n_fds; i++) { + ((int *)CMSG_DATA(cmsg))[i] = -1; + } + + if (recvmsg(sock, &msghdr, 0) < 0) { + return(-1); + } + for (i = 0; i < n_fds; i++) { + fds[i] = ((int *)CMSG_DATA(cmsg))[i]; + } + n_fds = (cmsg->cmsg_len - sizeof(struct cmsghdr)) / sizeof(int); + return n_fds; +} + +/** shortcut for receiving only one \e fd from \e sock */ +static int ancil_recv_fd(int sock, int *fd) { + ANCIL_FD_BUFFER(1) buffer; + + return ancil_recv_fds_with_buffer(sock, fd, 1, &buffer) == 1 ? 0 : -1; +} + +/** send \e n_fds handles in \e fds to unix domain socket \e sock */ +static int ancil_send_fds_with_buffer(int sock, const int *fds, unsigned n_fds, void *buffer) { + struct msghdr msghdr; + char nothing = '!'; + struct iovec nothing_ptr; + struct cmsghdr *cmsg; + int i; + + nothing_ptr.iov_base = ¬hing; + nothing_ptr.iov_len = 1; + msghdr.msg_name = NULL; + msghdr.msg_namelen = 0; + msghdr.msg_iov = ¬hing_ptr; + msghdr.msg_iovlen = 1; + msghdr.msg_flags = 0; + msghdr.msg_control = buffer; + msghdr.msg_controllen = sizeof(struct cmsghdr) + sizeof(int) * n_fds; + cmsg = CMSG_FIRSTHDR(&msghdr); + cmsg->cmsg_len = msghdr.msg_controllen; + cmsg->cmsg_level = SOL_SOCKET; + cmsg->cmsg_type = SCM_RIGHTS; + for (i = 0; i < n_fds; i++) { + ((int *)CMSG_DATA(cmsg))[i] = fds[i]; + } + return sendmsg(sock, &msghdr, 0) >= 0 ? 0 : -1; +} + +/** shortcut for sending only one \e fd to \e sock */ +static int ancil_send_fd(int sock, int fd) +{ + ANCIL_FD_BUFFER(1) buffer; + + return ancil_send_fds_with_buffer(sock, &fd, 1, &buffer); +} + +/* + * libancillary end + */ + + +/** name of unix domain socket for communication with Android FastdVpnService */ +#define CTRL_SOCK_NAME "fastd_tun_sock" + +/** message sent by Android FastdVpnService to indicate successful protection of socket */ +#define PROTECT_OK 'X' + +/** message sent by Android FastdVpnService when protecting socket failed */ +#define PROTECT_ERROR 'E' + +/** establish the unix domain socket with Android GUI */ +static void init_ctrl_sock(void) { + /* Must keep consistent with FastdVpnService */ + struct sockaddr_un addr; + + if ((ctx.android_ctrl_sock_fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) { + exit_errno("could not create unix domain socket"); + } + + memset(&addr, 0, sizeof(addr)); + addr.sun_family = AF_UNIX; + addr.sun_path[0] = 0; /* Linux's abstract unix domain socket name */ + strncpy(addr.sun_path + 1, CTRL_SOCK_NAME, sizeof(addr.sun_path) - 2); + int socklen = offsetof(struct sockaddr_un, sun_path) + strlen(CTRL_SOCK_NAME) + 1; + + if (connect(ctx.android_ctrl_sock_fd, (struct sockaddr*)&addr, socklen) == -1) { + exit_errno("could not connect to Android LocalServerSocket"); + } +} + +/** receive TUN fd from Android GUI; this is the only way to open TUN device on non-rooted Android */ +int fastd_android_receive_tunfd(void) { + init_ctrl_sock(); + + int handle; + if (ancil_recv_fd(ctx.android_ctrl_sock_fd, &handle)) { + exit_errno("could not receive TUN handle from Android"); + } else { + pr_debug("received fd: %u", handle); + } + + return handle; +} + +/** send fastd pid to Android GUI for later signal sending (HUP, TERM etc) */ +void fastd_android_send_pid(void) { + char pid[20]; + snprintf(pid, sizeof(pid), "%u", (unsigned)getpid()); + if (write(ctx.android_ctrl_sock_fd, pid, strlen(pid)) != strlen(pid)) { + exit_errno("send pid"); + } +} + +/** report \e fd to Android GUI to be protected (i.e. not to be routed via TUN) */ +bool fastd_android_protect_socket(int fd) { + if (!conf.android_integration) { + /* rooted/non-GUI mode */ + return true; + } + + pr_debug("sending fd to protect"); + if (ancil_send_fd(ctx.android_ctrl_sock_fd, fd) == -1) { + exit_errno("could not send handle to Android for protecting"); + } + + char buf[20]; + if (read(ctx.android_ctrl_sock_fd, buf, sizeof(buf)) == -1) { + exit_errno("read ack"); + } + return buf[0] == PROTECT_OK; +} + +#endif /* __ANDROID__ */ + diff --git a/src/compat.h b/src/compat.h index c73a340..411c6bb 100644 --- a/src/compat.h +++ b/src/compat.h @@ -94,7 +94,7 @@ struct ethhdr { /** Replacement function for *BSD systems not supporting get_current_dir_name() */ static inline char *get_current_dir_name(void) { -#if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) || defined(__APPLE__) +#if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) || defined(__APPLE__) || defined(__ANDROID__) return getcwd(NULL, 0); diff --git a/src/config.c b/src/config.c index 7a0cb4e..1c74026 100644 --- a/src/config.c +++ b/src/config.c @@ -2,6 +2,10 @@ Copyright (c) 2012-2014, Matthias Schiffer All rights reserved. + Android port contributor: + Copyright (c) 2014-2015, Haofeng "Rick" Lei + All rights reserved. + Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: @@ -382,6 +386,11 @@ static void configure_user(void) { conf.uid = getuid(); conf.gid = getgid(); +#ifdef __ANDROID__ + if (conf.user || conf.group) { + exit_error("config error: setting user/group is not supported on Android"); + } +#else if (conf.user) { struct passwd pwd, *pwdr; size_t bufspace = 1024; @@ -441,6 +450,7 @@ static void configure_user(void) { conf.groups[i] = groups[i]; } } +#endif } /** Initializes global configuration that depends on the configured methods */ diff --git a/src/cpuid.h b/src/cpuid.h index 9382156..671be87 100644 --- a/src/cpuid.h +++ b/src/cpuid.h @@ -50,7 +50,7 @@ static inline uint64_t fastd_cpuid(void) { unsigned eax, ebx, ecx, edx; - __asm__("cpuid" : "=a" (eax), "=b" (ebx), "=c" (ecx), "=d" (edx) : "a" (1)); + __asm__ __volatile__ ("mov %%ebx, %%edi;" "cpuid;" "xchgl %%ebx, %%edi;" : "=a" (eax), "=D" (ebx), "=c" (ecx), "=d" (edx) : "a" (1)); return ((uint64_t)ecx) << 32 | edx; } diff --git a/src/fastd.c b/src/fastd.c index 43dacc7..1b2eb33 100644 --- a/src/fastd.c +++ b/src/fastd.c @@ -2,6 +2,10 @@ Copyright (c) 2012-2014, Matthias Schiffer All rights reserved. + Android port contributor: + Copyright (c) 2014-2015, Haofeng "Rick" Lei + All rights reserved. + Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: @@ -246,6 +250,12 @@ static inline void write_pid(void) { if (!conf.pid_file) return; +#ifdef __ANDROID__ + if (conf.android_integration) { + pr_warn("fastd doesn't support pid file in GUI integration mode on Android"); + return; + } +#endif uid_t uid = geteuid(); gid_t gid = getegid(); @@ -256,17 +266,17 @@ static inline void write_pid(void) { pr_debug_errno("seteuid"); } - int fd = open(conf.pid_file, O_WRONLY|O_CREAT|O_TRUNC, 0666); - if (fd < 0) { - pr_error_errno("can't write PID file: open"); + FILE *f = fopen(conf.pid_file, "w"); + if (f == NULL) { + pr_error_errno("can't write PID file: fopen"); goto end; } - if (dprintf(fd, "%u", (unsigned)getpid()) < 0) - pr_error_errno("can't write PID file: dprintf"); + if (fprintf(f, "%u", (unsigned)getpid()) < 0) + pr_error_errno("can't write PID file: fprintf"); - if (close(fd) < 0) - pr_warn_errno("close"); + if (fclose(f) < 0) + pr_warn_errno("fclose"); end: if (seteuid(uid) < 0) diff --git a/src/fastd.h b/src/fastd.h index 6e4cda6..3d62053 100644 --- a/src/fastd.h +++ b/src/fastd.h @@ -2,6 +2,10 @@ Copyright (c) 2012-2014, Matthias Schiffer All rights reserved. + Android port contributor: + Copyright (c) 2014-2015, Haofeng "Rick" Lei + All rights reserved. + Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: @@ -239,6 +243,10 @@ struct fastd_config { char *status_socket; /**< The path of the status socket */ #endif +#ifdef __ANDROID__ + bool android_integration; /**< Enable Android GUI integration features */ +#endif + bool daemon; /**< Set to make fastd fork to the background after initialization */ char *pid_file; /**< A filename to write fastd's PID to */ @@ -296,6 +304,10 @@ struct fastd_context { int tunfd; /**< The file descriptor of the tunnel interface */ +#ifdef __ANDROID__ + int android_ctrl_sock_fd; /**< The unix domain socket for communicating with Android GUI */ +#endif + size_t n_socks; /**< The number of sockets in socks */ fastd_socket_t *socks; /**< Array of all sockets */ @@ -337,6 +349,12 @@ fastd_socket_t * fastd_socket_open(fastd_peer_t *peer, int af); void fastd_socket_close(fastd_socket_t *sock); void fastd_socket_error(fastd_socket_t *sock); +#ifdef __ANDROID__ +int fastd_android_receive_tunfd(void); +void fastd_android_send_pid(void); +bool fastd_android_protect_socket(int fd); +#endif + void fastd_resolve_peer(fastd_peer_t *peer, fastd_remote_t *remote); void fastd_tuntap_open(void); diff --git a/src/options.c b/src/options.c index b54c086..f8a358e 100644 --- a/src/options.c +++ b/src/options.c @@ -2,6 +2,10 @@ Copyright (c) 2012-2014, Matthias Schiffer All rights reserved. + Android port contributor: + Copyright (c) 2014-2015, Haofeng "Rick" Lei + All rights reserved. + Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: @@ -325,6 +329,13 @@ static void option_forward(void) { #endif +#ifdef __ANDROID__ +/** Handles the --android-integration option */ +static void option_android_integration(void) { + conf.android_integration = true; +} +#endif + #ifdef WITH_CMDLINE_COMMANDS /** Handles the --on-pre-up option */ diff --git a/src/options.def.h b/src/options.def.h index 9ea0476..6d0efca 100644 --- a/src/options.def.h +++ b/src/options.def.h @@ -38,6 +38,11 @@ OPTION(option_forward, "--forward", "Enables forwarding of packets between peers SEPARATOR; #endif +#ifdef __ANDROID__ +OPTION(option_android_integration, "--android-integration", "Enable integration with Android GUI"); +SEPARATOR; +#endif + #ifdef WITH_CMDLINE_COMMANDS OPTION_ARG(option_on_pre_up, "--on-pre-up", "", "Sets a shell command to execute before interface creation"); OPTION_ARG(option_on_up, "--on-up", "", "Sets a shell command to execute after interface creation"); diff --git a/src/poll.c b/src/poll.c index 549d097..d4da8f1 100644 --- a/src/poll.c +++ b/src/poll.c @@ -81,7 +81,7 @@ static inline int epoll_wait_unblocked(int epfd, struct epoll_event *events, int void fastd_poll_init(void) { - ctx.epoll_fd = epoll_create1(0); + ctx.epoll_fd = epoll_create(1); if (ctx.epoll_fd < 0) exit_errno("epoll_create1"); diff --git a/src/send.c b/src/send.c index 8b9aae7..6e425c6 100644 --- a/src/send.c +++ b/src/send.c @@ -2,6 +2,10 @@ Copyright (c) 2012-2014, Matthias Schiffer All rights reserved. + Android port contributor: + Copyright (c) 2014-2015, Haofeng "Rick" Lei + All rights reserved. + Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: @@ -38,6 +42,11 @@ /** Adds packet info to ancillary control messages */ static inline void add_pktinfo(struct msghdr *msg, const fastd_peer_address_t *local_addr) { +#ifdef __ANDROID__ + /* PKTINFO will mess with Android VpnService.protect(socket) */ + if (conf.android_integration) + return; +#endif if (!local_addr) return; diff --git a/src/socket.c b/src/socket.c index e72ec94..5e33010 100644 --- a/src/socket.c +++ b/src/socket.c @@ -152,6 +152,13 @@ static int bind_socket(const fastd_bind_address_t *addr, bool warn) { goto error; } +#ifdef __ANDROID__ + if (!fastd_android_protect_socket(fd)) { + pr_error("error protecting socket"); + goto error; + } +#endif + return fd; error: diff --git a/src/tuntap.c b/src/tuntap.c index e35858e..2656486 100644 --- a/src/tuntap.c +++ b/src/tuntap.c @@ -2,6 +2,10 @@ Copyright (c) 2012-2014, Matthias Schiffer All rights reserved. + Android port contributor: + Copyright (c) 2014-2015, Haofeng "Rick" Lei + All rights reserved. + Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: @@ -35,7 +39,6 @@ #include #include - #ifdef __linux__ #include @@ -60,16 +63,15 @@ static const bool multiaf_tun = false; static const bool multiaf_tun = true; #endif +#ifdef __linux__ -#if defined(__linux__) +/** Opens the TUN/TAP device helper shared by Android and Linux targets */ +static void tuntap_open_linux(const char * dev_name) { + pr_debug("initializing tun/tap device..."); -/** Opens the TUN/TAP device */ -void fastd_tuntap_open(void) { struct ifreq ifr = {}; - pr_debug("initializing tun/tap device..."); - - if ((ctx.tunfd = open("/dev/net/tun", O_RDWR|O_NONBLOCK)) < 0) + if ((ctx.tunfd = open(dev_name, O_RDWR|O_NONBLOCK)) < 0) exit_errno("could not open tun/tap device file"); if (conf.ifname) @@ -115,6 +117,40 @@ void fastd_tuntap_open(void) { pr_debug("tun/tap device initialized."); } +#endif + +#if defined(__ANDROID__) + +/** Opens the TUN/TAP device */ +void fastd_tuntap_open(void) { + pr_debug("initializing tun device..."); + + if (conf.android_integration) { + if (conf.mode != MODE_TUN) { + exit_error("Non root Android supports only TUN mode"); + } + + pr_debug("using android TUN fd"); + ctx.tunfd = fastd_android_receive_tunfd(); + + fastd_android_send_pid(); + + fastd_poll_set_fd_tuntap(); + + pr_debug("tun device initialized."); + } else { + /* this requires root on Android */ + tuntap_open_linux("/dev/tun"); + } +} + +#elif defined(__linux__) + +/** Opens the TUN/TAP device */ +void fastd_tuntap_open(void) { + tuntap_open_linux("/dev/net/tun"); +} + #elif defined(__FreeBSD__) || defined(__OpenBSD__) /** Sets the MTU of the TUN/TAP device */ -- cgit v1.2.3