diff options
Diffstat (limited to 'mtu.c')
| -rw-r--r-- | mtu.c | 290 |
1 files changed, 0 insertions, 290 deletions
@@ -1,290 +0,0 @@ -/* - * OpenVPN -- An application to securely tunnel IP networks - * over a single TCP/UDP port, with support for SSL/TLS-based - * session authentication and key exchange, - * packet encryption, packet authentication, and - * packet compression. - * - * Copyright (C) 2002-2010 OpenVPN Technologies, Inc. <sales@openvpn.net> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 - * as published by the Free Software Foundation. - * - * 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 (see the file COPYING included with this - * distribution); if not, write to the Free Software Foundation, Inc., - * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - */ - -#include "syshead.h" - -#include "common.h" -#include "buffer.h" -#include "error.h" -#include "integer.h" -#include "mtu.h" - -#include "memdbg.h" - -/* allocate a buffer for socket or tun layer */ -void -alloc_buf_sock_tun (struct buffer *buf, - const struct frame *frame, - const bool tuntap_buffer, - const unsigned int align_mask) -{ - /* allocate buffer for overlapped I/O */ - *buf = alloc_buf (BUF_SIZE (frame)); - ASSERT (buf_init (buf, FRAME_HEADROOM_ADJ (frame, align_mask))); - buf->len = tuntap_buffer ? MAX_RW_SIZE_TUN (frame) : MAX_RW_SIZE_LINK (frame); - ASSERT (buf_safe (buf, 0)); -} - -void -frame_finalize (struct frame *frame, - bool link_mtu_defined, - int link_mtu, - bool tun_mtu_defined, - int tun_mtu) -{ - /* Set link_mtu based on command line options */ - if (tun_mtu_defined) - { - ASSERT (!link_mtu_defined); - frame->link_mtu = tun_mtu + TUN_LINK_DELTA (frame); - } - else - { - ASSERT (link_mtu_defined); - frame->link_mtu = link_mtu; - } - - if (TUN_MTU_SIZE (frame) < TUN_MTU_MIN) - { - msg (M_WARN, "TUN MTU value (%d) must be at least %d", TUN_MTU_SIZE (frame), TUN_MTU_MIN); - frame_print (frame, M_FATAL, "MTU is too small"); - } - - frame->link_mtu_dynamic = frame->link_mtu; - - frame->extra_buffer += PAYLOAD_ALIGN; -} - -/* - * Set the tun MTU dynamically. - */ -void -frame_set_mtu_dynamic (struct frame *frame, int mtu, unsigned int flags) -{ - -#ifdef ENABLE_DEBUG - const int orig_mtu = mtu; - const int orig_link_mtu_dynamic = frame->link_mtu_dynamic; -#endif - - ASSERT (mtu >= 0); - - if (flags & SET_MTU_TUN) - mtu += TUN_LINK_DELTA (frame); - - if (!(flags & SET_MTU_UPPER_BOUND) || mtu < frame->link_mtu_dynamic) - { - frame->link_mtu_dynamic = constrain_int ( - mtu, - EXPANDED_SIZE_MIN (frame), - EXPANDED_SIZE (frame)); - } - - dmsg (D_MTU_DEBUG, "MTU DYNAMIC mtu=%d, flags=%u, %d -> %d", - orig_mtu, - flags, - orig_link_mtu_dynamic, - frame->link_mtu_dynamic); -} - -/* - * Move extra_frame octets into extra_tun. Used by fragmenting code - * to adjust frame relative to its position in the buffer processing - * queue. - */ -void -frame_subtract_extra (struct frame *frame, const struct frame *src) -{ - frame->extra_frame -= src->extra_frame; - frame->extra_tun += src->extra_frame; -} - -void -frame_print (const struct frame *frame, - int level, - const char *prefix) -{ - struct gc_arena gc = gc_new (); - struct buffer out = alloc_buf_gc (256, &gc); - if (prefix) - buf_printf (&out, "%s ", prefix); - buf_printf (&out, "["); - buf_printf (&out, " L:%d", frame->link_mtu); - buf_printf (&out, " D:%d", frame->link_mtu_dynamic); - buf_printf (&out, " EF:%d", frame->extra_frame); - buf_printf (&out, " EB:%d", frame->extra_buffer); - buf_printf (&out, " ET:%d", frame->extra_tun); - buf_printf (&out, " EL:%d", frame->extra_link); - if (frame->align_flags && frame->align_adjust) - buf_printf (&out, " AF:%u/%d", frame->align_flags, frame->align_adjust); - buf_printf (&out, " ]"); - - msg (level, "%s", out.data); - gc_free (&gc); -} - -#define MTUDISC_NOT_SUPPORTED_MSG "--mtu-disc is not supported on this OS" - -void -set_mtu_discover_type (int sd, int mtu_type) -{ - if (mtu_type >= 0) - { -#if defined(HAVE_SETSOCKOPT) && defined(SOL_IP) && defined(IP_MTU_DISCOVER) - if (setsockopt - (sd, SOL_IP, IP_MTU_DISCOVER, &mtu_type, sizeof (mtu_type))) - msg (M_ERR, "Error setting IP_MTU_DISCOVER type=%d on TCP/UDP socket", - mtu_type); -#else - msg (M_FATAL, MTUDISC_NOT_SUPPORTED_MSG); -#endif - } -} - -int -translate_mtu_discover_type_name (const char *name) -{ -#if defined(IP_PMTUDISC_DONT) && defined(IP_PMTUDISC_WANT) && defined(IP_PMTUDISC_DO) - if (!strcmp (name, "yes")) - return IP_PMTUDISC_DO; - if (!strcmp (name, "maybe")) - return IP_PMTUDISC_WANT; - if (!strcmp (name, "no")) - return IP_PMTUDISC_DONT; - msg (M_FATAL, - "invalid --mtu-disc type: '%s' -- valid types are 'yes', 'maybe', or 'no'", - name); -#else - msg (M_FATAL, MTUDISC_NOT_SUPPORTED_MSG); -#endif - return -1; /* NOTREACHED */ -} - -#if EXTENDED_SOCKET_ERROR_CAPABILITY - -struct probehdr -{ - uint32_t ttl; - struct timeval tv; -}; - -const char * -format_extended_socket_error (int fd, int *mtu, struct gc_arena *gc) -{ - int res; - struct probehdr rcvbuf; - struct iovec iov; - struct msghdr msg; - struct cmsghdr *cmsg; - struct sock_extended_err *e; - struct sockaddr_in addr; - struct buffer out = alloc_buf_gc (256, gc); - char *cbuf = (char *) gc_malloc (256, false, gc); - - *mtu = 0; - - while (true) - { - memset (&rcvbuf, -1, sizeof (rcvbuf)); - iov.iov_base = &rcvbuf; - iov.iov_len = sizeof (rcvbuf); - msg.msg_name = (uint8_t *) &addr; - msg.msg_namelen = sizeof (addr); - msg.msg_iov = &iov; - msg.msg_iovlen = 1; - msg.msg_flags = 0; - msg.msg_control = cbuf; - msg.msg_controllen = 256; /* size of cbuf */ - - res = recvmsg (fd, &msg, MSG_ERRQUEUE); - if (res < 0) - goto exit; - - e = NULL; - - for (cmsg = CMSG_FIRSTHDR (&msg); cmsg; cmsg = CMSG_NXTHDR (&msg, cmsg)) - { - if (cmsg->cmsg_level == SOL_IP) - { - if (cmsg->cmsg_type == IP_RECVERR) - { - e = (struct sock_extended_err *) CMSG_DATA (cmsg); - } - else - { - buf_printf (&out ,"CMSG=%d|", cmsg->cmsg_type); - } - } - } - if (e == NULL) - { - buf_printf (&out, "NO-INFO|"); - goto exit; - } - - switch (e->ee_errno) - { - case ETIMEDOUT: - buf_printf (&out, "ETIMEDOUT|"); - break; - case EMSGSIZE: - buf_printf (&out, "EMSGSIZE Path-MTU=%d|", e->ee_info); - *mtu = e->ee_info; - break; - case ECONNREFUSED: - buf_printf (&out, "ECONNREFUSED|"); - break; - case EPROTO: - buf_printf (&out, "EPROTO|"); - break; - case EHOSTUNREACH: - buf_printf (&out, "EHOSTUNREACH|"); - break; - case ENETUNREACH: - buf_printf (&out, "ENETUNREACH|"); - break; - case EACCES: - buf_printf (&out, "EACCES|"); - break; - default: - buf_printf (&out, "UNKNOWN|"); - break; - } - } - - exit: - buf_rmtail (&out, '|'); - return BSTR (&out); -} - -void -set_sock_extended_error_passing (int sd) -{ - int on = 1; - if (setsockopt (sd, SOL_IP, IP_RECVERR, &on, sizeof (on))) - msg (M_WARN | M_ERRNO, - "Note: enable extended error passing on TCP/UDP socket failed (IP_RECVERR)"); -} - -#endif |