open_tun_generic already contains the logic required to find a device name when not specified b the user. For this reason the DCO case can easily leverage on function and avoid code duplication.
Signed-off-by: Antonio Quartulli <a...@unstable.cc> --- Changes from v6: * do not touch tls_multi in do_open_tun as it's still NULL (caused crash) * re-assign disable_dco field in pre_connect object, if DCO is disabled by open_tun() in do_open_tun() Changes from v5: * create TUN device when invoking --mktun with DCO enabled. Current code segfaults. * fix message printing "..device created" for DCO cases * print error string (and not just error code) when a DCO iface cannot be created * when creating DCO device, if a TUN device with the same name is found, disable DCO and use the existing device * don't use tunname as it contains the wrong string. Use dev or dynamic_name instead Changes from v4: * in open_tun_generic() use sizeof(tunname) when copying to tunname Changes from v3: * explicitly mention "DCO" in message when DCO device is successfully opened, as per Arne's request Changes from v2: * do not abuse the dynamic_name variable. Rather use 'dev' when no dynamic name is requested * ignore dev-node when using DCO, to avoid messing up naming logic in open_tun_generic. dev-node has sense when using DCO * add comment as to why we need to fill tunname Changes from v1: * improved INFO message when device already exists as per Arne's request src/openvpn/init.c | 31 +++++++- src/openvpn/init.h | 2 +- src/openvpn/options.c | 7 ++ src/openvpn/tun.c | 159 ++++++++++++++++++++++++++++++++---------- src/openvpn/tun.h | 2 +- 5 files changed, 162 insertions(+), 39 deletions(-) diff --git a/src/openvpn/init.c b/src/openvpn/init.c index 03221cbb..1adc06c9 100644 --- a/src/openvpn/init.c +++ b/src/openvpn/init.c @@ -1054,7 +1054,7 @@ do_genkey(const struct options *options) * Persistent TUN/TAP device management mode? */ bool -do_persist_tuntap(const struct options *options, openvpn_net_ctx_t *ctx) +do_persist_tuntap(struct options *options, openvpn_net_ctx_t *ctx) { if (options->persist_config) { @@ -1069,6 +1069,26 @@ do_persist_tuntap(const struct options *options, openvpn_net_ctx_t *ctx) msg(M_FATAL|M_OPTERR, "options --mktun or --rmtun should only be used together with --dev"); } + +#if defined(ENABLE_DCO) + if (dco_enabled(options)) + { + /* creating a DCO interface via --mktun is not supported as it does not + * make much sense. Since DCO is enabled by default, people may run into + * this without knowing, therefore this case should be properly handled. + * + * Disable DCO if --mktun was provided and print a message to let + * user know. + */ + if (dev_type_enum(options->dev, options->dev_type) == DEV_TYPE_TUN) + { + msg(M_WARN, "Note: --mktun does not support DCO. Creating TUN interface."); + } + + options->tuntap_options.disable_dco = true; + } +#endif + #ifdef ENABLE_FEATURE_TUN_PERSIST tuncfg(options->dev, options->dev_type, options->dev_node, options->persist_mode, @@ -1763,7 +1783,14 @@ do_open_tun(struct context *c) #endif /* open the tun device */ open_tun(c->options.dev, c->options.dev_type, c->options.dev_node, - c->c1.tuntap); + c->c1.tuntap, &c->net_ctx); + + /* DCO may have been disabled by open_tun(). propagate change */ + c->options.tuntap_options.disable_dco = c->c1.tuntap->options.disable_dco; + if (c->options.pre_connect->tuntap_options_defined) + { + c->options.pre_connect->tuntap_options.disable_dco = c->c1.tuntap->options.disable_dco; + } /* set the hardware address */ if (c->options.lladdr) diff --git a/src/openvpn/init.h b/src/openvpn/init.h index 2b8c2dcc..5f412a33 100644 --- a/src/openvpn/init.h +++ b/src/openvpn/init.h @@ -56,7 +56,7 @@ bool print_openssl_info(const struct options *options); bool do_genkey(const struct options *options); -bool do_persist_tuntap(const struct options *options, openvpn_net_ctx_t *ctx); +bool do_persist_tuntap(struct options *options, openvpn_net_ctx_t *ctx); bool possibly_become_daemon(const struct options *options); diff --git a/src/openvpn/options.c b/src/openvpn/options.c index 233c02e0..705bb79a 100644 --- a/src/openvpn/options.c +++ b/src/openvpn/options.c @@ -3528,6 +3528,13 @@ options_postprocess_mutate(struct options *o, struct env_set *es) o->verify_hash_no_ca = true; } + if (dco_enabled(o) && o->dev_node) + { + msg(M_WARN, "Note: ignoring --dev-node as it has no effect when using " + "data channel offload"); + o->dev_node = NULL; + } + /* * Save certain parms before modifying options during connect, especially * when using --pull diff --git a/src/openvpn/tun.c b/src/openvpn/tun.c index e12f0369..d75d75e3 100644 --- a/src/openvpn/tun.c +++ b/src/openvpn/tun.c @@ -37,6 +37,7 @@ #include "syshead.h" +#include "openvpn.h" #include "tun.h" #include "fdmisc.h" #include "common.h" @@ -1718,10 +1719,10 @@ read_tun_header(struct tuntap *tt, uint8_t *buf, int len) #endif /* if defined (TARGET_OPENBSD) || (defined(TARGET_DARWIN) && HAVE_NET_IF_UTUN_H) */ -#if !(defined(_WIN32) || defined(TARGET_LINUX)) +#if !defined(_WIN32) static void open_tun_generic(const char *dev, const char *dev_type, const char *dev_node, - bool dynamic, struct tuntap *tt) + bool dynamic, struct tuntap *tt, openvpn_net_ctx_t *ctx) { char tunname[256]; char dynamic_name[256]; @@ -1780,6 +1781,18 @@ open_tun_generic(const char *dev, const char *dev_type, const char *dev_node, "/dev/%s%d", dev, i); openvpn_snprintf(dynamic_name, sizeof(dynamic_name), "%s%d", dev, i); +#if defined(TARGET_LINUX) + if (!tt->options.disable_dco) + { + if (open_tun_dco(tt, ctx, dynamic_name) == 0) + { + dynamic_opened = true; + msg(M_INFO, "DCO device %s opened", dynamic_name); + break; + } + } + else +#endif /* if defined(TARGET_LINUX) */ if ((tt->fd = open(tunname, O_RDWR)) > 0) { dynamic_opened = true; @@ -1801,30 +1814,81 @@ open_tun_generic(const char *dev, const char *dev_type, const char *dev_node, } } - if (!dynamic_opened) +#if defined(TARGET_LINUX) + if (!tt->options.disable_dco) { - /* has named device existed before? if so, don't destroy at end */ - if (if_nametoindex( dev ) > 0) + if (!dynamic_opened) { - msg(M_INFO, "TUN/TAP device %s exists previously, keep at program end", dev ); - tt->persistent_if = true; - } + /* if dynamic_opened was true, then we already created the + * interface named 'dynamic_name', otherwise we have to create + * now the interface 'dev'. + * + * The variable 'dev_node' is totally ignored in the DCO case + * because it is unset by options post-processing as it makes no + * sense in this context. + */ + int ret = open_tun_dco(tt, ctx, dev); + if (ret == -EEXIST) + { + char type[IFACE_TYPE_LEN_MAX]; - if ((tt->fd = open(tunname, O_RDWR)) < 0) - { - msg(M_ERR, "Cannot open TUN/TAP dev %s", tunname); + ret = net_iface_type(ctx, dev, type); + if (ret < 0 || strcmp(type, "ovpn-dco") != 0) + { + msg(M_WARN, "Existing non-DCO device %s found. Disabling DCO", + dev); + tt->options.disable_dco = true; + + open_tun(dev, dev_type, dev_node, tt, ctx); + return; + } + else + { + msg(M_INFO, "DCO device %s already exists, won't be destroyed at shutdown", + dev); + } + tt->persistent_if = true; + } + else if (ret < 0) + { + msg(M_ERR, "Cannot open DCO device %s: %s (%d)", dev, + strerror(-ret), ret); + } + else + { + msg(M_INFO, "DCO device %s opened", dev); + } } } + else +#endif /* if defined(TARGET_LINUX) */ + { + if (!dynamic_opened) + { + /* has named device existed before? if so, don't destroy at end */ + if (if_nametoindex( dev ) > 0) + { + msg(M_INFO, "TUN/TAP device %s exists previously, keep at program end", dev ); + tt->persistent_if = true; + } - set_nonblock(tt->fd); - set_cloexec(tt->fd); /* don't pass fd to scripts */ - msg(M_INFO, "TUN/TAP device %s opened", tunname); + if ((tt->fd = open(tunname, O_RDWR)) < 0) + { + msg(M_ERR, "Cannot open TUN/TAP dev %s", tunname); + } + } + + set_nonblock(tt->fd); + set_cloexec(tt->fd); /* don't pass fd to scripts */ + + msg(M_INFO, "TUN/TAP device %s opened", tunname); + } /* tt->actual_name is passed to up and down scripts and used as the ifconfig dev name */ tt->actual_name = string_alloc(dynamic_opened ? dynamic_name : dev, NULL); } } -#endif /* !_WIN32 && !TARGET_LINUX */ +#endif /* !_WIN32 */ #if !defined(_WIN32) static void @@ -1842,7 +1906,8 @@ close_tun_generic(struct tuntap *tt) #if defined (TARGET_ANDROID) void -open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt) +open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt, + openvpn_net_ctx_t *ctx) { #define ANDROID_TUNNAME "vpnservice-tun" struct user_pass up; @@ -1939,7 +2004,8 @@ read_tun(struct tuntap *tt, uint8_t *buf, int len) #if !PEDANTIC void -open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt) +open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt, + openvpn_net_ctx_t *ctx) { struct ifreq ifr; @@ -1950,6 +2016,12 @@ open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tun { open_null(tt); } +#if defined(TARGET_LINUX) + else if (!tt->options.disable_dco) + { + open_tun_generic(dev, dev_type, dev_node, true, tt, ctx); + } +#endif else { /* @@ -2056,7 +2128,8 @@ open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tun #else /* if !PEDANTIC */ void -open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt) +open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt, + openvpn_net_ctx_t *ctx) { ASSERT(0); } @@ -2081,7 +2154,8 @@ tuncfg(const char *dev, const char *dev_type, const char *dev_node, clear_tuntap(tt); tt->type = dev_type_enum(dev, dev_type); tt->options = *options; - open_tun(dev, dev_type, dev_node, tt); + + open_tun(dev, dev_type, dev_node, tt, ctx); if (ioctl(tt->fd, TUNSETPERSIST, persist_mode) < 0) { msg(M_ERR, "Cannot ioctl TUNSETPERSIST(%d) %s", persist_mode, dev); @@ -2199,6 +2273,12 @@ close_tun(struct tuntap *tt, openvpn_net_ctx_t *ctx) net_ctx_reset(ctx); } +#ifdef TARGET_LINUX + if (!tt->options.disable_dco) + { + close_tun_dco(tt, ctx); + } +#endif close_tun_generic(tt); free(tt); } @@ -2222,7 +2302,8 @@ read_tun(struct tuntap *tt, uint8_t *buf, int len) #endif void -open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt) +open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt, + openvpn_net_ctx_t *ctx) { int if_fd, ip_muxid, arp_muxid, arp_fd, ppa = -1; struct lifreq ifr; @@ -2574,9 +2655,10 @@ read_tun(struct tuntap *tt, uint8_t *buf, int len) #elif defined(TARGET_OPENBSD) void -open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt) +open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt, + openvpn_net_ctx_t *ctx) { - open_tun_generic(dev, dev_type, dev_node, true, tt); + open_tun_generic(dev, dev_type, dev_node, true, tt, ctx); /* Enable multicast on the interface */ if (tt->fd >= 0) @@ -2668,9 +2750,10 @@ read_tun(struct tuntap *tt, uint8_t *buf, int len) */ void -open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt) +open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt, + openvpn_net_ctx_t *ctx) { - open_tun_generic(dev, dev_type, dev_node, true, tt); + open_tun_generic(dev, dev_type, dev_node, true, tt, ctx); if (tt->fd >= 0) { @@ -2808,9 +2891,10 @@ freebsd_modify_read_write_return(int len) } void -open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt) +open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt, + openvpn_net_ctx_t *ctx) { - open_tun_generic(dev, dev_type, dev_node, true, tt); + open_tun_generic(dev, dev_type, dev_node, true, tt, ctx); if (tt->fd >= 0 && tt->type == DEV_TYPE_TUN) { @@ -2936,9 +3020,10 @@ dragonfly_modify_read_write_return(int len) } void -open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt) +open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt, + openvpn_net_ctx_t *ctx) { - open_tun_generic(dev, dev_type, dev_node, true, tt); + open_tun_generic(dev, dev_type, dev_node, true, tt, ctx); if (tt->fd >= 0) { @@ -3164,7 +3249,8 @@ open_darwin_utun(const char *dev, const char *dev_type, const char *dev_node, st #endif /* ifdef HAVE_NET_IF_UTUN_H */ void -open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt) +open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt, + openvpn_net_ctx_t *ctx) { #ifdef HAVE_NET_IF_UTUN_H /* If dev_node does not start start with utun assume regular tun/tap */ @@ -3190,7 +3276,7 @@ open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tun { /* No explicit utun and utun failed, try the generic way) */ msg(M_INFO, "Failed to open utun device. Falling back to /dev/tun device"); - open_tun_generic(dev, dev_type, NULL, true, tt); + open_tun_generic(dev, dev_type, NULL, true, tt, ctx); } else { @@ -3213,7 +3299,7 @@ open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tun dev_node = NULL; } - open_tun_generic(dev, dev_type, dev_node, true, tt); + open_tun_generic(dev, dev_type, dev_node, true, tt, ctx); } } @@ -3271,7 +3357,8 @@ read_tun(struct tuntap *tt, uint8_t *buf, int len) #elif defined(TARGET_AIX) void -open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt) +open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt, + openvpn_net_ctx_t *ctx) { char tunname[256]; char dynamic_name[20]; @@ -6580,7 +6667,8 @@ tuntap_post_open(struct tuntap *tt, const char *device_guid) } void -open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt) +open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt, + openvpn_net_ctx_t *ctx) { const char *device_guid = NULL; @@ -6881,9 +6969,10 @@ ipset2ascii_all(struct gc_arena *gc) #else /* generic */ void -open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt) +open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tuntap *tt, + openvpn_net_ctx_t *ctx) { - open_tun_generic(dev, dev_type, dev_node, true, tt); + open_tun_generic(dev, dev_type, dev_node, true, tt, ctx); } void diff --git a/src/openvpn/tun.h b/src/openvpn/tun.h index 5fcea590..cf02bf43 100644 --- a/src/openvpn/tun.h +++ b/src/openvpn/tun.h @@ -249,7 +249,7 @@ tuntap_ring_empty(struct tuntap *tt) */ void open_tun(const char *dev, const char *dev_type, const char *dev_node, - struct tuntap *tt); + struct tuntap *tt, openvpn_net_ctx_t *ctx); void close_tun(struct tuntap *tt, openvpn_net_ctx_t *ctx); -- 2.35.1 _______________________________________________ Openvpn-devel mailing list Openvpn-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/openvpn-devel