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/* |
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util.h -- process management and other utility functions |
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Copyright (C) 1998-2002 Ivo Timmermans <ivo@o2w.nl> |
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2000-2002 Guus Sliepen <guus@sliepen.eu.org> |
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2003 Marc Lehmannn <pcg@goof.com> |
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|
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This program is free software; you can redistribute it and/or modify |
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it under the terms of the GNU General Public License as published by |
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the Free Software Foundation; either version 2 of the License, or |
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(at your option) any later version. |
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|
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This program is distributed in the hope that it will be useful, |
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but WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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GNU General Public License for more details. |
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|
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You should have received a copy of the GNU General Public License |
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along with this program; if not, write to the Free Software |
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Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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*/ |
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|
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#ifndef UTIL_H__ |
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#define UTIL_H__ |
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|
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#include <sys/socket.h> |
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#include <netinet/in.h> |
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|
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#include <map> |
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|
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#include "device.h" |
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|
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#define SOCKADDR sockaddr_in // this is lame, I know |
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|
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/* |
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* check for an existing vped for this net, and write pid to pidfile |
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*/ |
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extern int write_pidfile (void); |
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|
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/* |
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* kill older vped |
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*/ |
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extern int kill_other (int signal); |
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|
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/* |
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* Detach from current terminal, write pidfile, kill parent |
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*/ |
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extern int detach (int do_detach); |
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|
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/* |
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* Set all files and paths according to netname |
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*/ |
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extern void make_names (void); |
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|
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/* |
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* check wether the given path is an absolute pathname |
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*/ |
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#define ABSOLUTE_PATH(c) ((c)[0] == '/') |
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|
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static inline void |
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id2mac (unsigned int id, void *m) |
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{ |
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mac &p = *(mac *)m; |
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|
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p[0] = 0xfe; |
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p[1] = 0xfd; |
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p[2] = 0x80; |
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p[3] = 0x00; |
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p[4] = id >> 8; |
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p[5] = id; |
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} |
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|
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#define mac2id(p) (p[0] & 0x01 ? 0 : (p[4] << 8) | p[5]) |
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|
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// a very simple fifo pkt-queue |
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class pkt_queue |
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{ |
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tap_packet *queue[QUEUEDEPTH]; |
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int i, j; |
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|
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public: |
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|
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void put (tap_packet *p); |
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tap_packet *get (); |
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|
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pkt_queue (); |
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~pkt_queue (); |
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}; |
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|
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struct sockinfo |
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{ |
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u32 host; |
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u16 port; |
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|
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void set (const SOCKADDR *sa) |
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{ |
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host = sa->sin_addr.s_addr; |
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port = sa->sin_port; |
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} |
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|
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sockinfo() |
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{ |
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host = port = 0; |
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} |
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|
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sockinfo(const SOCKADDR &sa) |
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{ |
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set (&sa); |
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} |
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|
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sockinfo(const SOCKADDR *sa) |
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{ |
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set (sa); |
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} |
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|
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SOCKADDR *sa() |
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{ |
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static SOCKADDR sa; |
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|
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sa.sin_family = AF_INET; |
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sa.sin_port = port; |
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sa.sin_addr.s_addr = host; |
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|
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return &sa; |
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} |
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|
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operator const char *(); |
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}; |
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|
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inline bool |
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operator == (const sockinfo &a, const sockinfo &b) |
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{ |
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return a.host == b.host && a.port == b.port; |
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} |
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|
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inline bool |
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operator < (const sockinfo &a, const sockinfo &b) |
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{ |
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return a.host < b.host |
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|| (a.host == b.host && a.port < b.port); |
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} |
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|
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// only do action once every x seconds per host. |
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// currently this is quite a slow implementation, |
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// but suffices for normal operation. |
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struct u32_rate_limiter : private map<u32, time_t> |
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{ |
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int every; |
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|
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bool can (u32 host); |
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|
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u32_rate_limiter (time_t every = 1) |
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{ |
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this->every = every; |
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} |
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}; |
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|
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struct net_rate_limiter : u32_rate_limiter |
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{ |
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bool can (SOCKADDR *sa) { return u32_rate_limiter::can((u32)sa->sin_addr.s_addr); } |
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bool can (sockinfo &si) { return u32_rate_limiter::can((u32)si.host); } |
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|
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net_rate_limiter (time_t every) : u32_rate_limiter (every) {} |
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}; |
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|
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struct sliding_window { |
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u32 v[(WINDOWSIZE + 31) / 32]; |
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u32 seq; |
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|
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void reset (u32 seqno) |
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{ |
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memset (v, -1, sizeof v); |
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seq = seqno; |
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} |
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|
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bool recv_ok (u32 seqno) |
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{ |
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if (seqno <= seq - WINDOWSIZE) |
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slog (L_ERR, _("received duplicate or outdated packet (received %08lx, expected %08lx)\n" |
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"possible replay attack, or just massive packet reordering"), seqno, seq + 1);//D |
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else if (seqno > seq + WINDOWSIZE) |
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slog (L_ERR, _("received duplicate or out-of-sync packet (received %08lx, expected %08lx)\n" |
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"possible replay attack, or just massive packet loss"), seqno, seq + 1);//D |
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else |
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{ |
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while (seqno > seq) |
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{ |
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seq++; |
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|
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u32 s = seq % WINDOWSIZE; |
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u32 *cell = v + (s >> 5); |
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u32 mask = 1 << (s & 31); |
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|
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*cell &= ~mask; |
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} |
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|
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u32 s = seqno % WINDOWSIZE; |
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u32 *cell = v + (s >> 5); |
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u32 mask = 1 << (s & 31); |
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|
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//printf ("received seqno %08lx, seq %08lx, mask %08lx is %08lx\n", seqno, seq, mask, ismask); |
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if (*cell & mask) |
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{ |
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slog (L_ERR, _("received duplicate packet (received %08lx, expected %08lx)\n" |
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"possible replay attack, or just packet duplication"), seqno, seq + 1);//D |
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return false; |
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} |
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else |
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{ |
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*cell |= mask; |
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return true; |
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} |
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} |
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} |
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}; |
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|
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#endif |
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|
