/* * Copyright (c) 1993, 1994, 1995, 1996, 1997, 1998 * The Regents of the University of California. 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. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the Computer Systems * Engineering Group at Lawrence Berkeley Laboratory. * 4. Neither the name of the University nor of the Laboratory may be used * to endorse or promote products derived from this software without * specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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. */ #ifndef lint static const char rcsid[] _U_ = "@(#) $Header: /tcpdump/master/libpcap/pcap.c,v 1.128 2008-12-23 20:13:29 guy Exp $ (LBL)"; #endif #ifdef HAVE_CONFIG_H #include "config.h" #endif #ifdef WIN32 #include #else /* WIN32 */ #if HAVE_INTTYPES_H #include #elif HAVE_STDINT_H #include #endif #ifdef HAVE_SYS_BITYPES_H #include #endif #include #endif /* WIN32 */ #include #include #include #if !defined(_MSC_VER) && !defined(__BORLANDC__) && !defined(__MINGW32__) #include #endif #include #include #ifdef HAVE_OS_PROTO_H #include "os-proto.h" #endif #ifdef MSDOS #include "pcap-dos.h" #endif #include "pcap-int.h" #ifdef HAVE_DAG_API #include #include #endif int pcap_not_initialized(pcap_t *pcap) { /* this means 'not initialized' */ return (PCAP_ERROR_NOT_ACTIVATED); } /* * Returns 1 if rfmon mode can be set on the pcap_t, 0 if it can't, * a PCAP_ERROR value on an error. */ int pcap_can_set_rfmon(pcap_t *p) { return (p->can_set_rfmon_op(p)); } /* * For systems where rfmon mode is never supported. */ static int pcap_cant_set_rfmon(pcap_t *p _U_) { return (0); } /* * Sets *tstamp_typesp to point to an array 1 or more supported time stamp * types; the return value is the number of supported time stamp types. * The list should be freed by a call to pcap_free_tstamp_types() when * you're done with it. * * A return value of 0 means "you don't get a choice of time stamp type", * in which case *tstamp_typesp is set to null. * * PCAP_ERROR is returned on error. */ int pcap_list_tstamp_types(pcap_t *p, int **tstamp_typesp) { if (p->tstamp_type_count == 0) { /* * We don't support multiple time stamp types. */ *tstamp_typesp = NULL; } else { *tstamp_typesp = (int*)calloc(sizeof(**tstamp_typesp), p->tstamp_type_count); if (*tstamp_typesp == NULL) { (void)snprintf(p->errbuf, sizeof(p->errbuf), "malloc: %s", pcap_strerror(errno)); return (PCAP_ERROR); } (void)memcpy(*tstamp_typesp, p->tstamp_type_list, sizeof(**tstamp_typesp) * p->tstamp_type_count); } return (p->tstamp_type_count); } /* * In Windows, you might have a library built with one version of the * C runtime library and an application built with another version of * the C runtime library, which means that the library might use one * version of malloc() and free() and the application might use another * version of malloc() and free(). If so, that means something * allocated by the library cannot be freed by the application, so we * need to have a pcap_free_tstamp_types() routine to free up the list * allocated by pcap_list_tstamp_types(), even though it's just a wrapper * around free(). */ void pcap_free_tstamp_types(int *tstamp_type_list) { free(tstamp_type_list); } /* * Default one-shot callback; overridden for capture types where the * packet data cannot be guaranteed to be available after the callback * returns, so that a copy must be made. */ static void pcap_oneshot(u_char *user, const struct pcap_pkthdr *h, const u_char *pkt) { struct oneshot_userdata *sp = (struct oneshot_userdata *)user; *sp->hdr = *h; *sp->pkt = pkt; } const u_char * pcap_next(pcap_t *p, struct pcap_pkthdr *h) { struct oneshot_userdata s; const u_char *pkt; s.hdr = h; s.pkt = &pkt; s.pd = p; if (pcap_dispatch(p, 1, p->oneshot_callback, (u_char *)&s) <= 0) return (0); return (pkt); } int pcap_next_ex(pcap_t *p, struct pcap_pkthdr **pkt_header, const u_char **pkt_data) { struct oneshot_userdata s; s.hdr = &p->pcap_header; s.pkt = pkt_data; s.pd = p; /* Saves a pointer to the packet headers */ *pkt_header= &p->pcap_header; if (p->sf.rfile != NULL) { int status; /* We are on an offline capture */ status = pcap_offline_read(p, 1, p->oneshot_callback, (u_char *)&s); /* * Return codes for pcap_offline_read() are: * - 0: EOF * - -1: error * - >1: OK * The first one ('0') conflicts with the return code of * 0 from pcap_read() meaning "no packets arrived before * the timeout expired", so we map it to -2 so you can * distinguish between an EOF from a savefile and a * "no packets arrived before the timeout expired, try * again" from a live capture. */ if (status == 0) return (-2); else return (status); } /* * Return codes for pcap_read() are: * - 0: timeout * - -1: error * - -2: loop was broken out of with pcap_breakloop() * - >1: OK * The first one ('0') conflicts with the return code of 0 from * pcap_offline_read() meaning "end of file". */ return (p->read_op(p, 1, p->oneshot_callback, (u_char *)&s)); } static void initialize_ops(pcap_t *p) { /* * Set operation pointers for operations that only work on * an activated pcap_t to point to a routine that returns * a "this isn't activated" error. */ p->read_op = (read_op_t)pcap_not_initialized; p->inject_op = (inject_op_t)pcap_not_initialized; p->setfilter_op = (setfilter_op_t)pcap_not_initialized; p->setdirection_op = (setdirection_op_t)pcap_not_initialized; p->set_datalink_op = (set_datalink_op_t)pcap_not_initialized; p->getnonblock_op = (getnonblock_op_t)pcap_not_initialized; p->setnonblock_op = (setnonblock_op_t)pcap_not_initialized; p->stats_op = (stats_op_t)pcap_not_initialized; #ifdef WIN32 p->setbuff_op = (setbuff_op_t)pcap_not_initialized; p->setmode_op = (setmode_op_t)pcap_not_initialized; p->setmintocopy_op = (setmintocopy_op_t)pcap_not_initialized; #endif /* * Default cleanup operation - implementations can override * this, but should call pcap_cleanup_live_common() after * doing their own additional cleanup. */ p->cleanup_op = pcap_cleanup_live_common; /* * In most cases, the standard one-short callback can * be used for pcap_next()/pcap_next_ex(). */ p->oneshot_callback = pcap_oneshot; } pcap_t * pcap_create_common(const char *source, char *ebuf) { pcap_t *p; p = malloc(sizeof(*p)); if (p == NULL) { snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s", pcap_strerror(errno)); return (NULL); } memset(p, 0, sizeof(*p)); #ifndef WIN32 p->fd = -1; /* not opened yet */ p->selectable_fd = -1; p->send_fd = -1; #endif p->opt.source = strdup(source); if (p->opt.source == NULL) { snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s", pcap_strerror(errno)); free(p); return (NULL); } /* * Default to "can't set rfmon mode"; if it's supported by * a platform, the create routine that called us can set * the op to its routine to check whether a particular * device supports it. */ p->can_set_rfmon_op = pcap_cant_set_rfmon; initialize_ops(p); /* put in some defaults*/ pcap_set_timeout(p, 0); pcap_set_snaplen(p, 65535); /* max packet size */ p->opt.promisc = 0; p->opt.buffer_size = 0; p->opt.tstamp_type = -1; /* default to not setting time stamp type */ return (p); } int pcap_check_activated(pcap_t *p) { if (p->activated) { snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "can't perform " " operation on activated capture"); return (-1); } return (0); } int pcap_set_snaplen(pcap_t *p, int snaplen) { if (pcap_check_activated(p)) return (PCAP_ERROR_ACTIVATED); p->snapshot = snaplen; return (0); } int pcap_set_promisc(pcap_t *p, int promisc) { if (pcap_check_activated(p)) return (PCAP_ERROR_ACTIVATED); p->opt.promisc = promisc; return (0); } int pcap_set_rfmon(pcap_t *p, int rfmon) { if (pcap_check_activated(p)) return (PCAP_ERROR_ACTIVATED); p->opt.rfmon = rfmon; return (0); } int pcap_set_timeout(pcap_t *p, int timeout_ms) { if (pcap_check_activated(p)) return (PCAP_ERROR_ACTIVATED); p->md.timeout = timeout_ms; return (0); } int pcap_set_tstamp_type(pcap_t *p, int tstamp_type) { int i; if (pcap_check_activated(p)) return (PCAP_ERROR_ACTIVATED); /* * If p->tstamp_type_count is 0, we don't support setting * the time stamp type at all. */ if (p->tstamp_type_count == 0) return (PCAP_ERROR_CANTSET_TSTAMP_TYPE); /* * Check whether we claim to support this type of time stamp. */ for (i = 0; i < p->tstamp_type_count; i++) { if (p->tstamp_type_list[i] == tstamp_type) { /* * Yes. */ p->opt.tstamp_type = tstamp_type; return (0); } } /* * No. We support setting the time stamp type, but not to this * particular value. */ return (PCAP_WARNING_TSTAMP_TYPE_NOTSUP); } int pcap_set_buffer_size(pcap_t *p, int buffer_size) { if (pcap_check_activated(p)) return (PCAP_ERROR_ACTIVATED); p->opt.buffer_size = buffer_size; return (0); } int pcap_activate(pcap_t *p) { int status; /* * Catch attempts to re-activate an already-activated * pcap_t; this should, for example, catch code that * calls pcap_open_live() followed by pcap_activate(), * as some code that showed up in a Stack Exchange * question did. */ if (pcap_check_activated(p)) return (PCAP_ERROR_ACTIVATED); status = p->activate_op(p); if (status >= 0) p->activated = 1; else { if (p->errbuf[0] == '\0') { /* * No error message supplied by the activate routine; * for the benefit of programs that don't specially * handle errors other than PCAP_ERROR, return the * error message corresponding to the status. */ snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "%s", pcap_statustostr(status)); } /* * Undo any operation pointer setting, etc. done by * the activate operation. */ initialize_ops(p); } return (status); } pcap_t * pcap_open_live(const char *source, int snaplen, int promisc, int to_ms, char *errbuf) { pcap_t *p; int status; p = pcap_create(source, errbuf); if (p == NULL) return (NULL); status = pcap_set_snaplen(p, snaplen); if (status < 0) goto fail; status = pcap_set_promisc(p, promisc); if (status < 0) goto fail; status = pcap_set_timeout(p, to_ms); if (status < 0) goto fail; /* * Mark this as opened with pcap_open_live(), so that, for * example, we show the full list of DLT_ values, rather * than just the ones that are compatible with capturing * when not in monitor mode. That allows existing applications * to work the way they used to work, but allows new applications * that know about the new open API to, for example, find out the * DLT_ values that they can select without changing whether * the adapter is in monitor mode or not. */ p->oldstyle = 1; status = pcap_activate(p); if (status < 0) goto fail; return (p); fail: if (status == PCAP_ERROR) snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s", source, p->errbuf); else if (status == PCAP_ERROR_NO_SUCH_DEVICE || status == PCAP_ERROR_PERM_DENIED || status == PCAP_ERROR_PROMISC_PERM_DENIED) snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s (%s)", source, pcap_statustostr(status), p->errbuf); else snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s", source, pcap_statustostr(status)); pcap_close(p); return (NULL); } int pcap_dispatch(pcap_t *p, int cnt, pcap_handler callback, u_char *user) { return (p->read_op(p, cnt, callback, user)); } /* * XXX - is this necessary? */ int pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user) { return (p->read_op(p, cnt, callback, user)); } int pcap_loop(pcap_t *p, int cnt, pcap_handler callback, u_char *user) { register int n; for (;;) { if (p->sf.rfile != NULL) { /* * 0 means EOF, so don't loop if we get 0. */ n = pcap_offline_read(p, cnt, callback, user); } else { /* * XXX keep reading until we get something * (or an error occurs) */ do { n = p->read_op(p, cnt, callback, user); } while (n == 0); } if (n <= 0) return (n); if (cnt > 0) { cnt -= n; if (cnt <= 0) return (0); } } } /* * Force the loop in "pcap_read()" or "pcap_read_offline()" to terminate. */ void pcap_breakloop(pcap_t *p) { p->break_loop = 1; } int pcap_datalink(pcap_t *p) { return (p->linktype); } int pcap_datalink_ext(pcap_t *p) { return (p->linktype_ext); } int pcap_list_datalinks(pcap_t *p, int **dlt_buffer) { if (p->dlt_count == 0) { /* * We couldn't fetch the list of DLTs, which means * this platform doesn't support changing the * DLT for an interface. Return a list of DLTs * containing only the DLT this device supports. */ *dlt_buffer = (int*)malloc(sizeof(**dlt_buffer)); if (*dlt_buffer == NULL) { (void)snprintf(p->errbuf, sizeof(p->errbuf), "malloc: %s", pcap_strerror(errno)); return (-1); } **dlt_buffer = p->linktype; return (1); } else { *dlt_buffer = (int*)calloc(sizeof(**dlt_buffer), p->dlt_count); if (*dlt_buffer == NULL) { (void)snprintf(p->errbuf, sizeof(p->errbuf), "malloc: %s", pcap_strerror(errno)); return (-1); } (void)memcpy(*dlt_buffer, p->dlt_list, sizeof(**dlt_buffer) * p->dlt_count); return (p->dlt_count); } } /* * In Windows, you might have a library built with one version of the * C runtime library and an application built with another version of * the C runtime library, which means that the library might use one * version of malloc() and free() and the application might use another * version of malloc() and free(). If so, that means something * allocated by the library cannot be freed by the application, so we * need to have a pcap_free_datalinks() routine to free up the list * allocated by pcap_list_datalinks(), even though it's just a wrapper * around free(). */ void pcap_free_datalinks(int *dlt_list) { free(dlt_list); } int pcap_set_datalink(pcap_t *p, int dlt) { int i; const char *dlt_name; if (p->dlt_count == 0 || p->set_datalink_op == NULL) { /* * We couldn't fetch the list of DLTs, or we don't * have a "set datalink" operation, which means * this platform doesn't support changing the * DLT for an interface. Check whether the new * DLT is the one this interface supports. */ if (p->linktype != dlt) goto unsupported; /* * It is, so there's nothing we need to do here. */ return (0); } for (i = 0; i < p->dlt_count; i++) if (p->dlt_list[i] == dlt) break; if (i >= p->dlt_count) goto unsupported; if (p->dlt_count == 2 && p->dlt_list[0] == DLT_EN10MB && dlt == DLT_DOCSIS) { /* * This is presumably an Ethernet device, as the first * link-layer type it offers is DLT_EN10MB, and the only * other type it offers is DLT_DOCSIS. That means that * we can't tell the driver to supply DOCSIS link-layer * headers - we're just pretending that's what we're * getting, as, presumably, we're capturing on a dedicated * link to a Cisco Cable Modem Termination System, and * it's putting raw DOCSIS frames on the wire inside low-level * Ethernet framing. */ p->linktype = dlt; return (0); } if (p->set_datalink_op(p, dlt) == -1) return (-1); p->linktype = dlt; return (0); unsupported: dlt_name = pcap_datalink_val_to_name(dlt); if (dlt_name != NULL) { (void) snprintf(p->errbuf, sizeof(p->errbuf), "%s is not one of the DLTs supported by this device", dlt_name); } else { (void) snprintf(p->errbuf, sizeof(p->errbuf), "DLT %d is not one of the DLTs supported by this device", dlt); } return (-1); } /* * This array is designed for mapping upper and lower case letter * together for a case independent comparison. The mappings are * based upon ascii character sequences. */ static const u_char charmap[] = { (u_char)'\000', (u_char)'\001', (u_char)'\002', (u_char)'\003', (u_char)'\004', (u_char)'\005', (u_char)'\006', (u_char)'\007', (u_char)'\010', (u_char)'\011', (u_char)'\012', (u_char)'\013', (u_char)'\014', (u_char)'\015', (u_char)'\016', (u_char)'\017', (u_char)'\020', (u_char)'\021', (u_char)'\022', (u_char)'\023', (u_char)'\024', (u_char)'\025', (u_char)'\026', (u_char)'\027', (u_char)'\030', (u_char)'\031', (u_char)'\032', (u_char)'\033', (u_char)'\034', (u_char)'\035', (u_char)'\036', (u_char)'\037', (u_char)'\040', (u_char)'\041', (u_char)'\042', (u_char)'\043', (u_char)'\044', (u_char)'\045', (u_char)'\046', (u_char)'\047', (u_char)'\050', (u_char)'\051', (u_char)'\052', (u_char)'\053', (u_char)'\054', (u_char)'\055', (u_char)'\056', (u_char)'\057', (u_char)'\060', (u_char)'\061', (u_char)'\062', (u_char)'\063', (u_char)'\064', (u_char)'\065', (u_char)'\066', (u_char)'\067', (u_char)'\070', (u_char)'\071', (u_char)'\072', (u_char)'\073', (u_char)'\074', (u_char)'\075', (u_char)'\076', (u_char)'\077', (u_char)'\100', (u_char)'\141', (u_char)'\142', (u_char)'\143', (u_char)'\144', (u_char)'\145', (u_char)'\146', (u_char)'\147', (u_char)'\150', (u_char)'\151', (u_char)'\152', (u_char)'\153', (u_char)'\154', (u_char)'\155', (u_char)'\156', (u_char)'\157', (u_char)'\160', (u_char)'\161', (u_char)'\162', (u_char)'\163', (u_char)'\164', (u_char)'\165', (u_char)'\166', (u_char)'\167', (u_char)'\170', (u_char)'\171', (u_char)'\172', (u_char)'\133', (u_char)'\134', (u_char)'\135', (u_char)'\136', (u_char)'\137', (u_char)'\140', (u_char)'\141', (u_char)'\142', (u_char)'\143', (u_char)'\144', (u_char)'\145', (u_char)'\146', (u_char)'\147', (u_char)'\150', (u_char)'\151', (u_char)'\152', (u_char)'\153', (u_char)'\154', (u_char)'\155', (u_char)'\156', (u_char)'\157', (u_char)'\160', (u_char)'\161', (u_char)'\162', (u_char)'\163', (u_char)'\164', (u_char)'\165', (u_char)'\166', (u_char)'\167', (u_char)'\170', (u_char)'\171', (u_char)'\172', (u_char)'\173', (u_char)'\174', (u_char)'\175', (u_char)'\176', (u_char)'\177', (u_char)'\200', (u_char)'\201', (u_char)'\202', (u_char)'\203', (u_char)'\204', (u_char)'\205', (u_char)'\206', (u_char)'\207', (u_char)'\210', (u_char)'\211', (u_char)'\212', (u_char)'\213', (u_char)'\214', (u_char)'\215', (u_char)'\216', (u_char)'\217', (u_char)'\220', (u_char)'\221', (u_char)'\222', (u_char)'\223', (u_char)'\224', (u_char)'\225', (u_char)'\226', (u_char)'\227', (u_char)'\230', (u_char)'\231', (u_char)'\232', (u_char)'\233', (u_char)'\234', (u_char)'\235', (u_char)'\236', (u_char)'\237', (u_char)'\240', (u_char)'\241', (u_char)'\242', (u_char)'\243', (u_char)'\244', (u_char)'\245', (u_char)'\246', (u_char)'\247', (u_char)'\250', (u_char)'\251', (u_char)'\252', (u_char)'\253', (u_char)'\254', (u_char)'\255', (u_char)'\256', (u_char)'\257', (u_char)'\260', (u_char)'\261', (u_char)'\262', (u_char)'\263', (u_char)'\264', (u_char)'\265', (u_char)'\266', (u_char)'\267', (u_char)'\270', (u_char)'\271', (u_char)'\272', (u_char)'\273', (u_char)'\274', (u_char)'\275', (u_char)'\276', (u_char)'\277', (u_char)'\300', (u_char)'\341', (u_char)'\342', (u_char)'\343', (u_char)'\344', (u_char)'\345', (u_char)'\346', (u_char)'\347', (u_char)'\350', (u_char)'\351', (u_char)'\352', (u_char)'\353', (u_char)'\354', (u_char)'\355', (u_char)'\356', (u_char)'\357', (u_char)'\360', (u_char)'\361', (u_char)'\362', (u_char)'\363', (u_char)'\364', (u_char)'\365', (u_char)'\366', (u_char)'\367', (u_char)'\370', (u_char)'\371', (u_char)'\372', (u_char)'\333', (u_char)'\334', (u_char)'\335', (u_char)'\336', (u_char)'\337', (u_char)'\340', (u_char)'\341', (u_char)'\342', (u_char)'\343', (u_char)'\344', (u_char)'\345', (u_char)'\346', (u_char)'\347', (u_char)'\350', (u_char)'\351', (u_char)'\352', (u_char)'\353', (u_char)'\354', (u_char)'\355', (u_char)'\356', (u_char)'\357', (u_char)'\360', (u_char)'\361', (u_char)'\362', (u_char)'\363', (u_char)'\364', (u_char)'\365', (u_char)'\366', (u_char)'\367', (u_char)'\370', (u_char)'\371', (u_char)'\372', (u_char)'\373', (u_char)'\374', (u_char)'\375', (u_char)'\376', (u_char)'\377', }; int pcap_strcasecmp(const char *s1, const char *s2) { register const u_char *cm = charmap, *us1 = (const u_char *)s1, *us2 = (const u_char *)s2; while (cm[*us1] == cm[*us2++]) if (*us1++ == '\0') return(0); return (cm[*us1] - cm[*--us2]); } struct dlt_choice { const char *name; const char *description; int dlt; }; #define DLT_CHOICE(code, description) { #code, description, code } #define DLT_CHOICE_SENTINEL { NULL, NULL, 0 } static struct dlt_choice dlt_choices[] = { DLT_CHOICE(DLT_NULL, "BSD loopback"), DLT_CHOICE(DLT_EN10MB, "Ethernet"), DLT_CHOICE(DLT_IEEE802, "Token ring"), DLT_CHOICE(DLT_ARCNET, "BSD ARCNET"), DLT_CHOICE(DLT_SLIP, "SLIP"), DLT_CHOICE(DLT_PPP, "PPP"), DLT_CHOICE(DLT_FDDI, "FDDI"), DLT_CHOICE(DLT_ATM_RFC1483, "RFC 1483 LLC-encapsulated ATM"), DLT_CHOICE(DLT_RAW, "Raw IP"), DLT_CHOICE(DLT_SLIP_BSDOS, "BSD/OS SLIP"), DLT_CHOICE(DLT_PPP_BSDOS, "BSD/OS PPP"), DLT_CHOICE(DLT_ATM_CLIP, "Linux Classical IP-over-ATM"), DLT_CHOICE(DLT_PPP_SERIAL, "PPP over serial"), DLT_CHOICE(DLT_PPP_ETHER, "PPPoE"), DLT_CHOICE(DLT_SYMANTEC_FIREWALL, "Symantec Firewall"), DLT_CHOICE(DLT_C_HDLC, "Cisco HDLC"), DLT_CHOICE(DLT_IEEE802_11, "802.11"), DLT_CHOICE(DLT_FRELAY, "Frame Relay"), DLT_CHOICE(DLT_LOOP, "OpenBSD loopback"), DLT_CHOICE(DLT_ENC, "OpenBSD encapsulated IP"), DLT_CHOICE(DLT_LINUX_SLL, "Linux cooked"), DLT_CHOICE(DLT_LTALK, "Localtalk"), DLT_CHOICE(DLT_PFLOG, "OpenBSD pflog file"), DLT_CHOICE(DLT_PFSYNC, "Packet filter state syncing"), DLT_CHOICE(DLT_PRISM_HEADER, "802.11 plus Prism header"), DLT_CHOICE(DLT_IP_OVER_FC, "RFC 2625 IP-over-Fibre Channel"), DLT_CHOICE(DLT_SUNATM, "Sun raw ATM"), DLT_CHOICE(DLT_IEEE802_11_RADIO, "802.11 plus radiotap header"), DLT_CHOICE(DLT_ARCNET_LINUX, "Linux ARCNET"), DLT_CHOICE(DLT_JUNIPER_MLPPP, "Juniper Multi-Link PPP"), DLT_CHOICE(DLT_JUNIPER_MLFR, "Juniper Multi-Link Frame Relay"), DLT_CHOICE(DLT_JUNIPER_ES, "Juniper Encryption Services PIC"), DLT_CHOICE(DLT_JUNIPER_GGSN, "Juniper GGSN PIC"), DLT_CHOICE(DLT_JUNIPER_MFR, "Juniper FRF.16 Frame Relay"), DLT_CHOICE(DLT_JUNIPER_ATM2, "Juniper ATM2 PIC"), DLT_CHOICE(DLT_JUNIPER_SERVICES, "Juniper Advanced Services PIC"), DLT_CHOICE(DLT_JUNIPER_ATM1, "Juniper ATM1 PIC"), DLT_CHOICE(DLT_APPLE_IP_OVER_IEEE1394, "Apple IP-over-IEEE 1394"), DLT_CHOICE(DLT_MTP2_WITH_PHDR, "SS7 MTP2 with Pseudo-header"), DLT_CHOICE(DLT_MTP2, "SS7 MTP2"), DLT_CHOICE(DLT_MTP3, "SS7 MTP3"), DLT_CHOICE(DLT_SCCP, "SS7 SCCP"), DLT_CHOICE(DLT_DOCSIS, "DOCSIS"), DLT_CHOICE(DLT_LINUX_IRDA, "Linux IrDA"), DLT_CHOICE(DLT_IEEE802_11_RADIO_AVS, "802.11 plus AVS radio information header"), DLT_CHOICE(DLT_JUNIPER_MONITOR, "Juniper Passive Monitor PIC"), DLT_CHOICE(DLT_PPP_PPPD, "PPP for pppd, with direction flag"), DLT_CHOICE(DLT_JUNIPER_PPPOE, "Juniper PPPoE"), DLT_CHOICE(DLT_JUNIPER_PPPOE_ATM, "Juniper PPPoE/ATM"), DLT_CHOICE(DLT_GPRS_LLC, "GPRS LLC"), DLT_CHOICE(DLT_GPF_T, "GPF-T"), DLT_CHOICE(DLT_GPF_F, "GPF-F"), DLT_CHOICE(DLT_JUNIPER_PIC_PEER, "Juniper PIC Peer"), DLT_CHOICE(DLT_ERF_ETH, "Ethernet with Endace ERF header"), DLT_CHOICE(DLT_ERF_POS, "Packet-over-SONET with Endace ERF header"), DLT_CHOICE(DLT_LINUX_LAPD, "Linux vISDN LAPD"), DLT_CHOICE(DLT_JUNIPER_ETHER, "Juniper Ethernet"), DLT_CHOICE(DLT_JUNIPER_PPP, "Juniper PPP"), DLT_CHOICE(DLT_JUNIPER_FRELAY, "Juniper Frame Relay"), DLT_CHOICE(DLT_JUNIPER_CHDLC, "Juniper C-HDLC"), DLT_CHOICE(DLT_MFR, "FRF.16 Frame Relay"), DLT_CHOICE(DLT_JUNIPER_VP, "Juniper Voice PIC"), DLT_CHOICE(DLT_A429, "Arinc 429"), DLT_CHOICE(DLT_A653_ICM, "Arinc 653 Interpartition Communication"), DLT_CHOICE(DLT_USB, "USB"), DLT_CHOICE(DLT_BLUETOOTH_HCI_H4, "Bluetooth HCI UART transport layer"), DLT_CHOICE(DLT_IEEE802_16_MAC_CPS, "IEEE 802.16 MAC Common Part Sublayer"), DLT_CHOICE(DLT_USB_LINUX, "USB with Linux header"), DLT_CHOICE(DLT_CAN20B, "Controller Area Network (CAN) v. 2.0B"), DLT_CHOICE(DLT_IEEE802_15_4_LINUX, "IEEE 802.15.4 with Linux padding"), DLT_CHOICE(DLT_PPI, "Per-Packet Information"), DLT_CHOICE(DLT_IEEE802_16_MAC_CPS_RADIO, "IEEE 802.16 MAC Common Part Sublayer plus radiotap header"), DLT_CHOICE(DLT_JUNIPER_ISM, "Juniper Integrated Service Module"), DLT_CHOICE(DLT_IEEE802_15_4, "IEEE 802.15.4 with FCS"), DLT_CHOICE(DLT_SITA, "SITA pseudo-header"), DLT_CHOICE(DLT_ERF, "Endace ERF header"), DLT_CHOICE(DLT_RAIF1, "Ethernet with u10 Networks pseudo-header"), DLT_CHOICE(DLT_IPMB, "IPMB"), DLT_CHOICE(DLT_JUNIPER_ST, "Juniper Secure Tunnel"), DLT_CHOICE(DLT_BLUETOOTH_HCI_H4_WITH_PHDR, "Bluetooth HCI UART transport layer plus pseudo-header"), DLT_CHOICE(DLT_AX25_KISS, "AX.25 with KISS header"), DLT_CHOICE(DLT_IEEE802_15_4_NONASK_PHY, "IEEE 802.15.4 with non-ASK PHY data"), DLT_CHOICE(DLT_MPLS, "MPLS with label as link-layer header"), DLT_CHOICE(DLT_USB_LINUX_MMAPPED, "USB with padded Linux header"), DLT_CHOICE(DLT_DECT, "DECT"), DLT_CHOICE(DLT_AOS, "AOS Space Data Link protocol"), DLT_CHOICE(DLT_WIHART, "Wireless HART"), DLT_CHOICE(DLT_FC_2, "Fibre Channel FC-2"), DLT_CHOICE(DLT_FC_2_WITH_FRAME_DELIMS, "Fibre Channel FC-2 with frame delimiters"), DLT_CHOICE(DLT_IPNET, "Solaris ipnet"), DLT_CHOICE(DLT_CAN_SOCKETCAN, "CAN-bus with SocketCAN headers"), DLT_CHOICE(DLT_IPV4, "Raw IPv4"), DLT_CHOICE(DLT_IPV6, "Raw IPv6"), DLT_CHOICE(DLT_IEEE802_15_4_NOFCS, "IEEE 802.15.4 without FCS"), DLT_CHOICE(DLT_JUNIPER_VS, "Juniper Virtual Server"), DLT_CHOICE(DLT_JUNIPER_SRX_E2E, "Juniper SRX E2E"), DLT_CHOICE(DLT_JUNIPER_FIBRECHANNEL, "Juniper Fibre Channel"), DLT_CHOICE(DLT_DVB_CI, "DVB-CI"), DLT_CHOICE(DLT_JUNIPER_ATM_CEMIC, "Juniper ATM CEMIC"), DLT_CHOICE(DLT_NFLOG, "Linux netfilter log messages"), DLT_CHOICE(DLT_NETANALYZER, "Ethernet with Hilscher netANALYZER pseudo-header"), DLT_CHOICE(DLT_NETANALYZER_TRANSPARENT, "Ethernet with Hilscher netANALYZER pseudo-header and with preamble and SFD"), DLT_CHOICE(DLT_IPOIB, "RFC 4391 IP-over-Infiniband"), DLT_CHOICE_SENTINEL }; int pcap_datalink_name_to_val(const char *name) { int i; for (i = 0; dlt_choices[i].name != NULL; i++) { if (pcap_strcasecmp(dlt_choices[i].name + sizeof("DLT_") - 1, name) == 0) return (dlt_choices[i].dlt); } return (-1); } const char * pcap_datalink_val_to_name(int dlt) { int i; for (i = 0; dlt_choices[i].name != NULL; i++) { if (dlt_choices[i].dlt == dlt) return (dlt_choices[i].name + sizeof("DLT_") - 1); } return (NULL); } const char * pcap_datalink_val_to_description(int dlt) { int i; for (i = 0; dlt_choices[i].name != NULL; i++) { if (dlt_choices[i].dlt == dlt) return (dlt_choices[i].description); } return (NULL); } struct tstamp_type_choice { const char *name; const char *description; int type; }; static struct tstamp_type_choice tstamp_type_choices[] = { { "host", "Host", PCAP_TSTAMP_HOST }, { "host_lowprec", "Host, low precision", PCAP_TSTAMP_HOST_LOWPREC }, { "host_hiprec", "Host, high precision", PCAP_TSTAMP_HOST_HIPREC }, { "adapter", "Adapter", PCAP_TSTAMP_ADAPTER }, { "adapter_unsynced", "Adapter, not synced with system time", PCAP_TSTAMP_ADAPTER_UNSYNCED }, { NULL, NULL, 0 } }; int pcap_tstamp_type_name_to_val(const char *name) { int i; for (i = 0; tstamp_type_choices[i].name != NULL; i++) { if (pcap_strcasecmp(tstamp_type_choices[i].name, name) == 0) return (tstamp_type_choices[i].type); } return (PCAP_ERROR); } const char * pcap_tstamp_type_val_to_name(int tstamp_type) { int i; for (i = 0; tstamp_type_choices[i].name != NULL; i++) { if (tstamp_type_choices[i].type == tstamp_type) return (tstamp_type_choices[i].name); } return (NULL); } const char * pcap_tstamp_type_val_to_description(int tstamp_type) { int i; for (i = 0; tstamp_type_choices[i].name != NULL; i++) { if (tstamp_type_choices[i].type == tstamp_type) return (tstamp_type_choices[i].description); } return (NULL); } int pcap_snapshot(pcap_t *p) { return (p->snapshot); } int pcap_is_swapped(pcap_t *p) { return (p->sf.swapped); } int pcap_major_version(pcap_t *p) { return (p->sf.version_major); } int pcap_minor_version(pcap_t *p) { return (p->sf.version_minor); } FILE * pcap_file(pcap_t *p) { return (p->sf.rfile); } int pcap_fileno(pcap_t *p) { #ifndef WIN32 return (p->fd); #else if (p->adapter != NULL) return ((int)(DWORD)p->adapter->hFile); else return (-1); #endif } #if !defined(WIN32) && !defined(MSDOS) int pcap_get_selectable_fd(pcap_t *p) { return (p->selectable_fd); } #endif void pcap_perror(pcap_t *p, char *prefix) { fprintf(stderr, "%s: %s\n", prefix, p->errbuf); } char * pcap_geterr(pcap_t *p) { return (p->errbuf); } int pcap_getnonblock(pcap_t *p, char *errbuf) { return (p->getnonblock_op(p, errbuf)); } /* * Get the current non-blocking mode setting, under the assumption that * it's just the standard POSIX non-blocking flag. * * We don't look at "p->nonblock", in case somebody tweaked the FD * directly. */ #if !defined(WIN32) && !defined(MSDOS) int pcap_getnonblock_fd(pcap_t *p, char *errbuf) { int fdflags; fdflags = fcntl(p->fd, F_GETFL, 0); if (fdflags == -1) { snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "F_GETFL: %s", pcap_strerror(errno)); return (-1); } if (fdflags & O_NONBLOCK) return (1); else return (0); } #endif int pcap_setnonblock(pcap_t *p, int nonblock, char *errbuf) { return (p->setnonblock_op(p, nonblock, errbuf)); } #if !defined(WIN32) && !defined(MSDOS) /* * Set non-blocking mode, under the assumption that it's just the * standard POSIX non-blocking flag. (This can be called by the * per-platform non-blocking-mode routine if that routine also * needs to do some additional work.) */ int pcap_setnonblock_fd(pcap_t *p, int nonblock, char *errbuf) { int fdflags; fdflags = fcntl(p->fd, F_GETFL, 0); if (fdflags == -1) { snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "F_GETFL: %s", pcap_strerror(errno)); return (-1); } if (nonblock) fdflags |= O_NONBLOCK; else fdflags &= ~O_NONBLOCK; if (fcntl(p->fd, F_SETFL, fdflags) == -1) { snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "F_SETFL: %s", pcap_strerror(errno)); return (-1); } return (0); } #endif #ifdef WIN32 /* * Generate a string for the last Win32-specific error (i.e. an error generated when * calling a Win32 API). * For errors occurred during standard C calls, we still use pcap_strerror() */ char * pcap_win32strerror(void) { DWORD error; static char errbuf[PCAP_ERRBUF_SIZE+1]; int errlen; char *p; error = GetLastError(); FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, error, 0, errbuf, PCAP_ERRBUF_SIZE, NULL); /* * "FormatMessage()" "helpfully" sticks CR/LF at the end of the * message. Get rid of it. */ errlen = strlen(errbuf); if (errlen >= 2) { errbuf[errlen - 1] = '\0'; errbuf[errlen - 2] = '\0'; } p = strchr(errbuf, '\0'); snprintf (p, sizeof(errbuf)-(p-errbuf), " (%lu)", error); return (errbuf); } #endif /* * Generate error strings for PCAP_ERROR_ and PCAP_WARNING_ values. */ const char * pcap_statustostr(int errnum) { static char ebuf[15+10+1]; switch (errnum) { case PCAP_WARNING: return("Generic warning"); case PCAP_WARNING_TSTAMP_TYPE_NOTSUP: return ("That type of time stamp is not supported by that device"); case PCAP_WARNING_PROMISC_NOTSUP: return ("That device doesn't support promiscuous mode"); case PCAP_ERROR: return("Generic error"); case PCAP_ERROR_BREAK: return("Loop terminated by pcap_breakloop"); case PCAP_ERROR_NOT_ACTIVATED: return("The pcap_t has not been activated"); case PCAP_ERROR_ACTIVATED: return ("The setting can't be changed after the pcap_t is activated"); case PCAP_ERROR_NO_SUCH_DEVICE: return ("No such device exists"); case PCAP_ERROR_RFMON_NOTSUP: return ("That device doesn't support monitor mode"); case PCAP_ERROR_NOT_RFMON: return ("That operation is supported only in monitor mode"); case PCAP_ERROR_PERM_DENIED: return ("You don't have permission to capture on that device"); case PCAP_ERROR_IFACE_NOT_UP: return ("That device is not up"); case PCAP_ERROR_CANTSET_TSTAMP_TYPE: return ("That device doesn't support setting the time stamp type"); case PCAP_ERROR_PROMISC_PERM_DENIED: return ("You don't have permission to capture in promiscuous mode on that device"); } (void)snprintf(ebuf, sizeof ebuf, "Unknown error: %d", errnum); return(ebuf); } /* * Not all systems have strerror(). */ const char * pcap_strerror(int errnum) { #ifdef HAVE_STRERROR return (strerror(errnum)); #else extern int sys_nerr; extern const char *const sys_errlist[]; static char ebuf[15+10+1]; if ((unsigned int)errnum < sys_nerr) return ((char *)sys_errlist[errnum]); (void)snprintf(ebuf, sizeof ebuf, "Unknown error: %d", errnum); return(ebuf); #endif } int pcap_setfilter(pcap_t *p, struct bpf_program *fp) { return (p->setfilter_op(p, fp)); } /* * Set direction flag, which controls whether we accept only incoming * packets, only outgoing packets, or both. * Note that, depending on the platform, some or all direction arguments * might not be supported. */ int pcap_setdirection(pcap_t *p, pcap_direction_t d) { if (p->setdirection_op == NULL) { snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "Setting direction is not implemented on this platform"); return (-1); } else return (p->setdirection_op(p, d)); } int pcap_stats(pcap_t *p, struct pcap_stat *ps) { return (p->stats_op(p, ps)); } static int pcap_stats_dead(pcap_t *p, struct pcap_stat *ps _U_) { snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "Statistics aren't available from a pcap_open_dead pcap_t"); return (-1); } #ifdef WIN32 int pcap_setbuff(pcap_t *p, int dim) { return (p->setbuff_op(p, dim)); } static int pcap_setbuff_dead(pcap_t *p, int dim) { snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "The kernel buffer size cannot be set on a pcap_open_dead pcap_t"); return (-1); } int pcap_setmode(pcap_t *p, int mode) { return (p->setmode_op(p, mode)); } static int pcap_setmode_dead(pcap_t *p, int mode) { snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "impossible to set mode on a pcap_open_dead pcap_t"); return (-1); } int pcap_setmintocopy(pcap_t *p, int size) { return (p->setmintocopy_op(p, size)); } static int pcap_setmintocopy_dead(pcap_t *p, int size) { snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "The mintocopy parameter cannot be set on a pcap_open_dead pcap_t"); return (-1); } #endif /* * On some platforms, we need to clean up promiscuous or monitor mode * when we close a device - and we want that to happen even if the * application just exits without explicitl closing devices. * On those platforms, we need to register a "close all the pcaps" * routine to be called when we exit, and need to maintain a list of * pcaps that need to be closed to clean up modes. * * XXX - not thread-safe. */ /* * List of pcaps on which we've done something that needs to be * cleaned up. * If there are any such pcaps, we arrange to call "pcap_close_all()" * when we exit, and have it close all of them. */ static struct pcap *pcaps_to_close; /* * TRUE if we've already called "atexit()" to cause "pcap_close_all()" to * be called on exit. */ static int did_atexit; static void pcap_close_all(void) { struct pcap *handle; while ((handle = pcaps_to_close) != NULL) pcap_close(handle); } int pcap_do_addexit(pcap_t *p) { /* * If we haven't already done so, arrange to have * "pcap_close_all()" called when we exit. */ if (!did_atexit) { if (atexit(pcap_close_all) == -1) { /* * "atexit()" failed; let our caller know. */ strncpy(p->errbuf, "atexit failed", PCAP_ERRBUF_SIZE); return (0); } did_atexit = 1; } return (1); } void pcap_add_to_pcaps_to_close(pcap_t *p) { p->md.next = pcaps_to_close; pcaps_to_close = p; } void pcap_remove_from_pcaps_to_close(pcap_t *p) { pcap_t *pc, *prevpc; for (pc = pcaps_to_close, prevpc = NULL; pc != NULL; prevpc = pc, pc = pc->md.next) { if (pc == p) { /* * Found it. Remove it from the list. */ if (prevpc == NULL) { /* * It was at the head of the list. */ pcaps_to_close = pc->md.next; } else { /* * It was in the middle of the list. */ prevpc->md.next = pc->md.next; } break; } } } void pcap_cleanup_live_common(pcap_t *p) { if (p->buffer != NULL) { free(p->buffer); p->buffer = NULL; } if (p->dlt_list != NULL) { free(p->dlt_list); p->dlt_list = NULL; p->dlt_count = 0; } if (p->tstamp_type_list != NULL) { free(p->tstamp_type_list); p->tstamp_type_list = NULL; p->tstamp_type_count = 0; } pcap_freecode(&p->fcode); #if !defined(WIN32) && !defined(MSDOS) if (p->fd >= 0) { close(p->fd); p->fd = -1; } p->selectable_fd = -1; p->send_fd = -1; #endif } static void pcap_cleanup_dead(pcap_t *p _U_) { /* Nothing to do. */ } pcap_t * pcap_open_dead(int linktype, int snaplen) { pcap_t *p; p = malloc(sizeof(*p)); if (p == NULL) return NULL; memset (p, 0, sizeof(*p)); p->snapshot = snaplen; p->linktype = linktype; p->stats_op = pcap_stats_dead; #ifdef WIN32 p->setbuff_op = pcap_setbuff_dead; p->setmode_op = pcap_setmode_dead; p->setmintocopy_op = pcap_setmintocopy_dead; #endif p->cleanup_op = pcap_cleanup_dead; p->activated = 1; return (p); } /* * API compatible with WinPcap's "send a packet" routine - returns -1 * on error, 0 otherwise. * * XXX - what if we get a short write? */ int pcap_sendpacket(pcap_t *p, const u_char *buf, int size) { if (p->inject_op(p, buf, size) == -1) return (-1); return (0); } /* * API compatible with OpenBSD's "send a packet" routine - returns -1 on * error, number of bytes written otherwise. */ int pcap_inject(pcap_t *p, const void *buf, size_t size) { return (p->inject_op(p, buf, size)); } void pcap_close(pcap_t *p) { if (p->opt.source != NULL) free(p->opt.source); p->cleanup_op(p); free(p); } /* * Given a BPF program, a pcap_pkthdr structure for a packet, and the raw * data for the packet, check whether the packet passes the filter. * Returns the return value of the filter program, which will be zero if * the packet doesn't pass and non-zero if the packet does pass. */ int pcap_offline_filter(struct bpf_program *fp, const struct pcap_pkthdr *h, const u_char *pkt) { struct bpf_insn *fcode = fp->bf_insns; if (fcode != NULL) return (bpf_filter(fcode, pkt, h->len, h->caplen)); else return (0); } /* * We make the version string static, and return a pointer to it, rather * than exporting the version string directly. On at least some UNIXes, * if you import data from a shared library into an program, the data is * bound into the program binary, so if the string in the version of the * library with which the program was linked isn't the same as the * string in the version of the library with which the program is being * run, various undesirable things may happen (warnings, the string * being the one from the version of the library with which the program * was linked, or even weirder things, such as the string being the one * from the library but being truncated). */ #ifdef HAVE_VERSION_H #include "version.h" #else static const char pcap_version_string[] = "libpcap version 1.x.y"; #endif #ifdef WIN32 /* * XXX - it'd be nice if we could somehow generate the WinPcap and libpcap * version numbers when building WinPcap. (It'd be nice to do so for * the packet.dll version number as well.) */ static const char wpcap_version_string[] = "4.0"; static const char pcap_version_string_fmt[] = "WinPcap version %s, based on %s"; static const char pcap_version_string_packet_dll_fmt[] = "WinPcap version %s (packet.dll version %s), based on %s"; static char *full_pcap_version_string; const char * pcap_lib_version(void) { char *packet_version_string; size_t full_pcap_version_string_len; if (full_pcap_version_string == NULL) { /* * Generate the version string. */ packet_version_string = PacketGetVersion(); if (strcmp(wpcap_version_string, packet_version_string) == 0) { /* * WinPcap version string and packet.dll version * string are the same; just report the WinPcap * version. */ full_pcap_version_string_len = (sizeof pcap_version_string_fmt - 4) + strlen(wpcap_version_string) + strlen(pcap_version_string); full_pcap_version_string = malloc(full_pcap_version_string_len); sprintf(full_pcap_version_string, pcap_version_string_fmt, wpcap_version_string, pcap_version_string); } else { /* * WinPcap version string and packet.dll version * string are different; that shouldn't be the * case (the two libraries should come from the * same version of WinPcap), so we report both * versions. */ full_pcap_version_string_len = (sizeof pcap_version_string_packet_dll_fmt - 6) + strlen(wpcap_version_string) + strlen(packet_version_string) + strlen(pcap_version_string); full_pcap_version_string = malloc(full_pcap_version_string_len); sprintf(full_pcap_version_string, pcap_version_string_packet_dll_fmt, wpcap_version_string, packet_version_string, pcap_version_string); } } return (full_pcap_version_string); } #elif defined(MSDOS) static char *full_pcap_version_string; const char * pcap_lib_version (void) { char *packet_version_string; size_t full_pcap_version_string_len; static char dospfx[] = "DOS-"; if (full_pcap_version_string == NULL) { /* * Generate the version string. */ full_pcap_version_string_len = sizeof dospfx + strlen(pcap_version_string); full_pcap_version_string = malloc(full_pcap_version_string_len); strcpy(full_pcap_version_string, dospfx); strcat(full_pcap_version_string, pcap_version_string); } return (full_pcap_version_string); } #else /* UN*X */ const char * pcap_lib_version(void) { return (pcap_version_string); } #endif