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pcap.c

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00001 /*
00002  * Copyright (c) 1993, 1994, 1995, 1996, 1997, 1998
00003  *  The Regents of the University of California.  All rights reserved.
00004  *
00005  * Redistribution and use in source and binary forms, with or without
00006  * modification, are permitted provided that the following conditions
00007  * are met:
00008  * 1. Redistributions of source code must retain the above copyright
00009  *    notice, this list of conditions and the following disclaimer.
00010  * 2. Redistributions in binary form must reproduce the above copyright
00011  *    notice, this list of conditions and the following disclaimer in the
00012  *    documentation and/or other materials provided with the distribution.
00013  * 3. All advertising materials mentioning features or use of this software
00014  *    must display the following acknowledgement:
00015  *  This product includes software developed by the Computer Systems
00016  *  Engineering Group at Lawrence Berkeley Laboratory.
00017  * 4. Neither the name of the University nor of the Laboratory may be used
00018  *    to endorse or promote products derived from this software without
00019  *    specific prior written permission.
00020  *
00021  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
00022  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
00023  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
00024  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
00025  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
00026  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
00027  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
00028  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
00029  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
00030  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
00031  * SUCH DAMAGE.
00032  */
00033 
00034 #ifndef lint
00035 static const char rcsid[] _U_ =
00036     "@(#) $Header: /tcpdump/master/libpcap/pcap.c,v 1.70 2003/12/18 23:32:34 guy Exp $ (LBL)";
00037 #endif
00038 
00039 #ifdef HAVE_CONFIG_H
00040 #include "config.h"
00041 #endif
00042 
00043 #ifdef WIN32
00044 #include <pcap-stdinc.h>
00045 #else /* WIN32 */
00046 #include <sys/types.h>
00047 #endif /* WIN32 */
00048 
00049 #include <stdio.h>
00050 #include <stdlib.h>
00051 #include <string.h>
00052 #ifndef WIN32
00053 #include <unistd.h>
00054 #endif
00055 #include <fcntl.h>
00056 #include <errno.h>
00057 
00058 #ifdef HAVE_OS_PROTO_H
00059 #include "os-proto.h"
00060 #endif
00061 
00062 #include "pcap-int.h"
00063 
00064 #ifdef HAVE_DAG_API
00065 #include <dagnew.h>
00066 #include <dagapi.h>
00067 #endif
00068 
00069 #ifdef HAVE_REMOTE
00070 #include <pcap-remote.h>
00071 #endif
00072 
00073 
00074 int
00075 pcap_dispatch(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
00076 {
00077 
00078     return p->read_op(p, cnt, callback, user);
00079 }
00080 
00081 /*
00082  * XXX - is this necessary?
00083  */
00084 int
00085 pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
00086 {
00087 
00088     return p->read_op(p, cnt, callback, user);
00089 }
00090 
00091 int
00092 pcap_loop(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
00093 {
00094     register int n;
00095 
00096 #ifdef HAVE_REMOTE
00097     /* Checks the capture type */
00098     if (p->rmt_clientside)
00099     {
00100         /* We are on an remote capture */
00101         if (!p->rmt_capstarted)
00102         {
00103             // if the capture has not started yet, please start it
00104             if (pcap_startcapture_remote(p) )
00105                 return -1;
00106         }
00107     }
00108 #endif /* HAVE_REMOTE */
00109 
00110     for (;;) {
00111         if (p->sf.rfile != NULL) {
00112             /*
00113              * 0 means EOF, so don't loop if we get 0.
00114              */
00115             n = pcap_offline_read(p, cnt, callback, user);
00116         } else {
00117             /*
00118              * XXX keep reading until we get something
00119              * (or an error occurs)
00120              */
00121             do {
00122                 n = p->read_op(p, cnt, callback, user);
00123             } while (n == 0);
00124         }
00125         if (n <= 0)
00126             return (n);
00127         if (cnt > 0) {
00128             cnt -= n;
00129             if (cnt <= 0)
00130                 return (0);
00131         }
00132     }
00133 }
00134 
00135 struct singleton {
00136     struct pcap_pkthdr *hdr;
00137     const u_char *pkt;
00138 };
00139 
00140 
00141 static void
00142 pcap_oneshot(u_char *userData, const struct pcap_pkthdr *h, const u_char *pkt)
00143 {
00144     struct singleton *sp = (struct singleton *)userData;
00145     *sp->hdr = *h;
00146     sp->pkt = pkt;
00147 }
00148 
00149 const u_char *
00150 pcap_next(pcap_t *p, struct pcap_pkthdr *h)
00151 {
00152     struct singleton s;
00153 
00154     s.hdr = h;
00155     if (pcap_dispatch(p, 1, pcap_oneshot, (u_char*)&s) <= 0)
00156         return (0);
00157     return (s.pkt);
00158 }
00159 
00160 struct pkt_for_fakecallback {
00161     struct pcap_pkthdr *hdr;
00162     const u_char **pkt;
00163 };
00164 
00165 static void
00166 pcap_fakecallback(u_char *userData, const struct pcap_pkthdr *h,
00167     const u_char *pkt)
00168 {
00169     struct pkt_for_fakecallback *sp = (struct pkt_for_fakecallback *)userData;
00170 
00171     *sp->hdr = *h;
00172     *sp->pkt = pkt;
00173 }
00174 
00175 int 
00176 pcap_next_ex(pcap_t *p, struct pcap_pkthdr **pkt_header,
00177     const u_char **pkt_data)
00178 {
00179     struct pkt_for_fakecallback s;
00180 
00181     s.hdr = &p->pcap_header;
00182     s.pkt = pkt_data;
00183 
00184     /* Saves a pointer to the packet headers */
00185     *pkt_header= &p->pcap_header;
00186 
00187 #ifdef HAVE_REMOTE
00188     /* Checks the capture type */
00189     if (p->rmt_clientside)
00190     {
00191         /* We are on an remote capture */
00192         if (!p->rmt_capstarted)
00193         {
00194             // if the capture has not started yet, please start it
00195             if (pcap_startcapture_remote(p) )
00196                 return -1;
00197         }
00198 
00199         return pcap_read_nocb_remote(p, pkt_header, (u_char **) pkt_data);
00200     }
00201 #endif /* HAVE_REMOTE */
00202 
00203     if (p->sf.rfile != NULL) {
00204         int status;
00205 
00206         /* We are on an offline capture */
00207         status = pcap_offline_read(p, 1, pcap_fakecallback,
00208             (u_char *)&s);
00209 
00210         /*
00211          * Return codes for pcap_offline_read() are:
00212          *   -  0: EOF
00213          *   - -1: error
00214          *   - >1: OK
00215          * The first one ('0') conflicts with the return code of
00216          * 0 from pcap_read() meaning "no packets arrived before
00217          * the timeout expired", so we map it to -2 so you can
00218          * distinguish between an EOF from a savefile and a
00219          * "no packets arrived before the timeout expired, try
00220          * again" from a live capture.
00221          */
00222         if (status == 0)
00223             return (-2);
00224         else
00225             return (status);
00226     }
00227 
00228     /*
00229      * Return codes for pcap_read() are:
00230      *   -  0: timeout
00231      *   - -1: error
00232      *   - -2: loop was broken out of with pcap_breakloop()
00233      *   - >1: OK
00234      * The first one ('0') conflicts with the return code of 0 from
00235      * pcap_offline_read() meaning "end of file".
00236     */
00237     return (p->read_op(p, 1, pcap_fakecallback, (u_char *)&s));
00238 }
00239 
00240 /*
00241  * Force the loop in "pcap_read()" or "pcap_read_offline()" to terminate.
00242  */
00243 void
00244 pcap_breakloop(pcap_t *p)
00245 {
00246     p->break_loop = 1;
00247 }
00248 
00249 int
00250 pcap_datalink(pcap_t *p)
00251 {
00252     return (p->linktype);
00253 }
00254 
00255 int
00256 pcap_list_datalinks(pcap_t *p, int **dlt_buffer)
00257 {
00258     if (p->dlt_count == 0) {
00259         /*
00260          * We couldn't fetch the list of DLTs, which means
00261          * this platform doesn't support changing the
00262          * DLT for an interface.  Return a list of DLTs
00263          * containing only the DLT this device supports.
00264          */
00265         *dlt_buffer = (int*)malloc(sizeof(**dlt_buffer));
00266         if (*dlt_buffer == NULL) {
00267             (void)snprintf(p->errbuf, sizeof(p->errbuf),
00268                 "malloc: %s", pcap_strerror(errno));
00269             return (-1);
00270         }
00271         **dlt_buffer = p->linktype;
00272         return (1);
00273     } else {
00274         *dlt_buffer = (int*)malloc(sizeof(**dlt_buffer) * p->dlt_count);
00275         if (*dlt_buffer == NULL) {
00276             (void)snprintf(p->errbuf, sizeof(p->errbuf),
00277                 "malloc: %s", pcap_strerror(errno));
00278             return (-1);
00279         }
00280         (void)memcpy(*dlt_buffer, p->dlt_list,
00281             sizeof(**dlt_buffer) * p->dlt_count);
00282         return (p->dlt_count);
00283     }
00284 }
00285 
00286 int
00287 pcap_set_datalink(pcap_t *p, int dlt)
00288 {
00289     int i;
00290     const char *dlt_name;
00291 
00292     if (p->dlt_count == 0 || p->set_datalink_op == NULL) {
00293         /*
00294          * We couldn't fetch the list of DLTs, or we don't
00295          * have a "set datalink" operation, which means
00296          * this platform doesn't support changing the
00297          * DLT for an interface.  Check whether the new
00298          * DLT is the one this interface supports.
00299          */
00300         if (p->linktype != dlt)
00301             goto unsupported;
00302 
00303         /*
00304          * It is, so there's nothing we need to do here.
00305          */
00306         return (0);
00307     }
00308     for (i = 0; i < p->dlt_count; i++)
00309         if (p->dlt_list[i] == dlt)
00310             break;
00311     if (i >= p->dlt_count)
00312         goto unsupported;
00313     if (p->dlt_count == 2 && p->dlt_list[0] == DLT_EN10MB &&
00314         dlt == DLT_DOCSIS) {
00315         /*
00316          * This is presumably an Ethernet device, as the first
00317          * link-layer type it offers is DLT_EN10MB, and the only
00318          * other type it offers is DLT_DOCSIS.  That means that
00319          * we can't tell the driver to supply DOCSIS link-layer
00320          * headers - we're just pretending that's what we're
00321          * getting, as, presumably, we're capturing on a dedicated
00322          * link to a Cisco Cable Modem Termination System, and
00323          * it's putting raw DOCSIS frames on the wire inside low-level
00324          * Ethernet framing.
00325          */
00326         p->linktype = dlt;
00327         return (0);
00328     }
00329     if (p->set_datalink_op(p, dlt) == -1)
00330         return (-1);
00331     p->linktype = dlt;
00332     return (0);
00333 
00334 unsupported:
00335     dlt_name = pcap_datalink_val_to_name(dlt);
00336     if (dlt_name != NULL) {
00337         (void) snprintf(p->errbuf, sizeof(p->errbuf),
00338             "%s is not one of the DLTs supported by this device",
00339             dlt_name);
00340     } else {
00341         (void) snprintf(p->errbuf, sizeof(p->errbuf),
00342             "DLT %d is not one of the DLTs supported by this device",
00343             dlt);
00344     }
00345     return (-1);
00346 }
00347 
00348 struct dlt_choice {
00349     const char *name;
00350     const char *description;
00351     int dlt;
00352 };
00353 
00354 #define DLT_CHOICE(code, description) { #code, description, code }
00355 #define DLT_CHOICE_SENTINEL { NULL, NULL, 0 }
00356 
00357 static struct dlt_choice dlt_choices[] = {
00358     DLT_CHOICE(DLT_NULL, "BSD loopback"),
00359     DLT_CHOICE(DLT_EN10MB, "Ethernet"),
00360     DLT_CHOICE(DLT_IEEE802, "Token ring"),
00361     DLT_CHOICE(DLT_ARCNET, "ARCNET"),
00362     DLT_CHOICE(DLT_SLIP, "SLIP"),
00363     DLT_CHOICE(DLT_PPP, "PPP"),
00364     DLT_CHOICE(DLT_FDDI, "FDDI"),
00365     DLT_CHOICE(DLT_ATM_RFC1483, "RFC 1483 IP-over-ATM"),
00366     DLT_CHOICE(DLT_RAW, "Raw IP"),
00367     DLT_CHOICE(DLT_SLIP_BSDOS, "BSD/OS SLIP"),
00368     DLT_CHOICE(DLT_PPP_BSDOS, "BSD/OS PPP"),
00369     DLT_CHOICE(DLT_ATM_CLIP, "Linux Classical IP-over-ATM"),
00370     DLT_CHOICE(DLT_PPP_SERIAL, "PPP over serial"),
00371     DLT_CHOICE(DLT_PPP_ETHER, "PPPoE"),
00372     DLT_CHOICE(DLT_C_HDLC, "Cisco HDLC"),
00373     DLT_CHOICE(DLT_IEEE802_11, "802.11"),
00374     DLT_CHOICE(DLT_FRELAY, "Frame Relay"),
00375     DLT_CHOICE(DLT_LOOP, "OpenBSD loopback"),
00376     DLT_CHOICE(DLT_ENC, "OpenBSD encapsulated IP"),
00377     DLT_CHOICE(DLT_LINUX_SLL, "Linux cooked"),
00378     DLT_CHOICE(DLT_LTALK, "Localtalk"),
00379     DLT_CHOICE(DLT_PFLOG, "OpenBSD pflog file"),
00380     DLT_CHOICE(DLT_PRISM_HEADER, "802.11 plus Prism header"),
00381     DLT_CHOICE(DLT_IP_OVER_FC, "RFC 2625 IP-over-Fibre Channel"),
00382     DLT_CHOICE(DLT_SUNATM, "Sun raw ATM"),
00383     DLT_CHOICE(DLT_IEEE802_11_RADIO, "802.11 plus radio information header"),
00384     DLT_CHOICE(DLT_ARCNET_LINUX, "Linux ARCNET"),
00385     DLT_CHOICE(DLT_DOCSIS, "DOCSIS"),
00386     DLT_CHOICE(DLT_LINUX_IRDA, "Linux IrDA"),
00387     DLT_CHOICE_SENTINEL
00388 };
00389 
00390 /*
00391  * This array is designed for mapping upper and lower case letter
00392  * together for a case independent comparison.  The mappings are
00393  * based upon ascii character sequences.
00394  */
00395 static const u_char charmap[] = {
00396     (u_char)'\000', (u_char)'\001', (u_char)'\002', (u_char)'\003',
00397     (u_char)'\004', (u_char)'\005', (u_char)'\006', (u_char)'\007',
00398     (u_char)'\010', (u_char)'\011', (u_char)'\012', (u_char)'\013',
00399     (u_char)'\014', (u_char)'\015', (u_char)'\016', (u_char)'\017',
00400     (u_char)'\020', (u_char)'\021', (u_char)'\022', (u_char)'\023',
00401     (u_char)'\024', (u_char)'\025', (u_char)'\026', (u_char)'\027',
00402     (u_char)'\030', (u_char)'\031', (u_char)'\032', (u_char)'\033',
00403     (u_char)'\034', (u_char)'\035', (u_char)'\036', (u_char)'\037',
00404     (u_char)'\040', (u_char)'\041', (u_char)'\042', (u_char)'\043',
00405     (u_char)'\044', (u_char)'\045', (u_char)'\046', (u_char)'\047',
00406     (u_char)'\050', (u_char)'\051', (u_char)'\052', (u_char)'\053',
00407     (u_char)'\054', (u_char)'\055', (u_char)'\056', (u_char)'\057',
00408     (u_char)'\060', (u_char)'\061', (u_char)'\062', (u_char)'\063',
00409     (u_char)'\064', (u_char)'\065', (u_char)'\066', (u_char)'\067',
00410     (u_char)'\070', (u_char)'\071', (u_char)'\072', (u_char)'\073',
00411     (u_char)'\074', (u_char)'\075', (u_char)'\076', (u_char)'\077',
00412     (u_char)'\100', (u_char)'\141', (u_char)'\142', (u_char)'\143',
00413     (u_char)'\144', (u_char)'\145', (u_char)'\146', (u_char)'\147',
00414     (u_char)'\150', (u_char)'\151', (u_char)'\152', (u_char)'\153',
00415     (u_char)'\154', (u_char)'\155', (u_char)'\156', (u_char)'\157',
00416     (u_char)'\160', (u_char)'\161', (u_char)'\162', (u_char)'\163',
00417     (u_char)'\164', (u_char)'\165', (u_char)'\166', (u_char)'\167',
00418     (u_char)'\170', (u_char)'\171', (u_char)'\172', (u_char)'\133',
00419     (u_char)'\134', (u_char)'\135', (u_char)'\136', (u_char)'\137',
00420     (u_char)'\140', (u_char)'\141', (u_char)'\142', (u_char)'\143',
00421     (u_char)'\144', (u_char)'\145', (u_char)'\146', (u_char)'\147',
00422     (u_char)'\150', (u_char)'\151', (u_char)'\152', (u_char)'\153',
00423     (u_char)'\154', (u_char)'\155', (u_char)'\156', (u_char)'\157',
00424     (u_char)'\160', (u_char)'\161', (u_char)'\162', (u_char)'\163',
00425     (u_char)'\164', (u_char)'\165', (u_char)'\166', (u_char)'\167',
00426     (u_char)'\170', (u_char)'\171', (u_char)'\172', (u_char)'\173',
00427     (u_char)'\174', (u_char)'\175', (u_char)'\176', (u_char)'\177',
00428     (u_char)'\200', (u_char)'\201', (u_char)'\202', (u_char)'\203',
00429     (u_char)'\204', (u_char)'\205', (u_char)'\206', (u_char)'\207',
00430     (u_char)'\210', (u_char)'\211', (u_char)'\212', (u_char)'\213',
00431     (u_char)'\214', (u_char)'\215', (u_char)'\216', (u_char)'\217',
00432     (u_char)'\220', (u_char)'\221', (u_char)'\222', (u_char)'\223',
00433     (u_char)'\224', (u_char)'\225', (u_char)'\226', (u_char)'\227',
00434     (u_char)'\230', (u_char)'\231', (u_char)'\232', (u_char)'\233',
00435     (u_char)'\234', (u_char)'\235', (u_char)'\236', (u_char)'\237',
00436     (u_char)'\240', (u_char)'\241', (u_char)'\242', (u_char)'\243',
00437     (u_char)'\244', (u_char)'\245', (u_char)'\246', (u_char)'\247',
00438     (u_char)'\250', (u_char)'\251', (u_char)'\252', (u_char)'\253',
00439     (u_char)'\254', (u_char)'\255', (u_char)'\256', (u_char)'\257',
00440     (u_char)'\260', (u_char)'\261', (u_char)'\262', (u_char)'\263',
00441     (u_char)'\264', (u_char)'\265', (u_char)'\266', (u_char)'\267',
00442     (u_char)'\270', (u_char)'\271', (u_char)'\272', (u_char)'\273',
00443     (u_char)'\274', (u_char)'\275', (u_char)'\276', (u_char)'\277',
00444     (u_char)'\300', (u_char)'\341', (u_char)'\342', (u_char)'\343',
00445     (u_char)'\344', (u_char)'\345', (u_char)'\346', (u_char)'\347',
00446     (u_char)'\350', (u_char)'\351', (u_char)'\352', (u_char)'\353',
00447     (u_char)'\354', (u_char)'\355', (u_char)'\356', (u_char)'\357',
00448     (u_char)'\360', (u_char)'\361', (u_char)'\362', (u_char)'\363',
00449     (u_char)'\364', (u_char)'\365', (u_char)'\366', (u_char)'\367',
00450     (u_char)'\370', (u_char)'\371', (u_char)'\372', (u_char)'\333',
00451     (u_char)'\334', (u_char)'\335', (u_char)'\336', (u_char)'\337',
00452     (u_char)'\340', (u_char)'\341', (u_char)'\342', (u_char)'\343',
00453     (u_char)'\344', (u_char)'\345', (u_char)'\346', (u_char)'\347',
00454     (u_char)'\350', (u_char)'\351', (u_char)'\352', (u_char)'\353',
00455     (u_char)'\354', (u_char)'\355', (u_char)'\356', (u_char)'\357',
00456     (u_char)'\360', (u_char)'\361', (u_char)'\362', (u_char)'\363',
00457     (u_char)'\364', (u_char)'\365', (u_char)'\366', (u_char)'\367',
00458     (u_char)'\370', (u_char)'\371', (u_char)'\372', (u_char)'\373',
00459     (u_char)'\374', (u_char)'\375', (u_char)'\376', (u_char)'\377',
00460 };
00461 
00462 int
00463 pcap_strcasecmp(const char *s1, const char *s2)
00464 {
00465     register const u_char   *cm = charmap,
00466                 *us1 = (u_char *)s1,
00467                 *us2 = (u_char *)s2;
00468 
00469     while (cm[*us1] == cm[*us2++])
00470         if (*us1++ == '\0')
00471             return(0);
00472     return (cm[*us1] - cm[*--us2]);
00473 }
00474 
00475 int
00476 pcap_datalink_name_to_val(const char *name)
00477 {
00478     int i;
00479 
00480     for (i = 0; dlt_choices[i].name != NULL; i++) {
00481         if (pcap_strcasecmp(dlt_choices[i].name + sizeof("DLT_") - 1,
00482             name) == 0)
00483             return (dlt_choices[i].dlt);
00484     }
00485     return (-1);
00486 }
00487 
00488 const char *
00489 pcap_datalink_val_to_name(int dlt)
00490 {
00491     int i;
00492 
00493     for (i = 0; dlt_choices[i].name != NULL; i++) {
00494         if (dlt_choices[i].dlt == dlt)
00495             return (dlt_choices[i].name + sizeof("DLT_") - 1);
00496     }
00497     return (NULL);
00498 }
00499 
00500 const char *
00501 pcap_datalink_val_to_description(int dlt)
00502 {
00503     int i;
00504 
00505     for (i = 0; dlt_choices[i].name != NULL; i++) {
00506         if (dlt_choices[i].dlt == dlt)
00507             return (dlt_choices[i].description);
00508     }
00509     return (NULL);
00510 }
00511 
00512 int
00513 pcap_snapshot(pcap_t *p)
00514 {
00515     return (p->snapshot);
00516 }
00517 
00518 int
00519 pcap_is_swapped(pcap_t *p)
00520 {
00521     return (p->sf.swapped);
00522 }
00523 
00524 int
00525 pcap_major_version(pcap_t *p)
00526 {
00527     return (p->sf.version_major);
00528 }
00529 
00530 int
00531 pcap_minor_version(pcap_t *p)
00532 {
00533     return (p->sf.version_minor);
00534 }
00535 
00536 FILE *
00537 pcap_file(pcap_t *p)
00538 {
00539     return (p->sf.rfile);
00540 }
00541 
00542 int
00543 pcap_fileno(pcap_t *p)
00544 {
00545 #ifdef HAVE_REMOTE
00546     if (p->rmt_clientside)
00547         return(p->rmt_sockdata);
00548 #endif /* HAVE_REMOTE */
00549 
00550 #ifndef WIN32
00551     return (p->fd);
00552 #else
00553     if (p->adapter != NULL)
00554         return ((int)(DWORD)p->adapter->hFile);
00555     else
00556         return (-1);
00557 #endif
00558 }
00559 
00560 #ifndef WIN32
00561 int
00562 pcap_get_selectable_fd(pcap_t *p)
00563 {
00564     return (p->selectable_fd);
00565 }
00566 #endif
00567 
00568 void
00569 pcap_perror(pcap_t *p, char *prefix)
00570 {
00571     fprintf(stderr, "%s: %s\n", prefix, p->errbuf);
00572 }
00573 
00574 char *
00575 pcap_geterr(pcap_t *p)
00576 {
00577     return (p->errbuf);
00578 }
00579 
00580 int
00581 pcap_getnonblock(pcap_t *p, char *errbuf)
00582 {
00583     return p->getnonblock_op(p, errbuf);
00584 }
00585 
00586 /*
00587  * Get the current non-blocking mode setting, under the assumption that
00588  * it's just the standard POSIX non-blocking flag.
00589  *
00590  * We don't look at "p->nonblock", in case somebody tweaked the FD
00591  * directly.
00592  */
00593 #ifndef WIN32
00594 int
00595 pcap_getnonblock_fd(pcap_t *p, char *errbuf)
00596 {
00597     int fdflags;
00598 
00599     fdflags = fcntl(p->fd, F_GETFL, 0);
00600     if (fdflags == -1) {
00601         snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "F_GETFL: %s",
00602             pcap_strerror(errno));
00603         return (-1);
00604     }
00605     if (fdflags & O_NONBLOCK)
00606         return (1);
00607     else
00608         return (0);
00609 }
00610 #endif
00611 
00612 int
00613 pcap_setnonblock(pcap_t *p, int nonblock, char *errbuf)
00614 {
00615     return p->setnonblock_op(p, nonblock, errbuf);
00616 }
00617 
00618 #ifndef WIN32
00619 /*
00620  * Set non-blocking mode, under the assumption that it's just the
00621  * standard POSIX non-blocking flag.  (This can be called by the
00622  * per-platform non-blocking-mode routine if that routine also
00623  * needs to do some additional work.)
00624  */
00625 int
00626 pcap_setnonblock_fd(pcap_t *p, int nonblock, char *errbuf)
00627 {
00628     int fdflags;
00629 
00630     fdflags = fcntl(p->fd, F_GETFL, 0);
00631     if (fdflags == -1) {
00632         snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "F_GETFL: %s",
00633             pcap_strerror(errno));
00634         return (-1);
00635     }
00636     if (nonblock)
00637         fdflags |= O_NONBLOCK;
00638     else
00639         fdflags &= ~O_NONBLOCK;
00640     if (fcntl(p->fd, F_SETFL, fdflags) == -1) {
00641         snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "F_SETFL: %s",
00642             pcap_strerror(errno));
00643         return (-1);
00644     }
00645     return (0);
00646 }
00647 #endif
00648 
00649 #ifdef WIN32
00650 /*
00651  * Generate a string for the last Win32-specific error (i.e. an error generated when 
00652  * calling a Win32 API).
00653  * For errors occurred during standard C calls, we still use pcap_strerror()
00654  */
00655 char *
00656 pcap_win32strerror(void)
00657 {
00658     DWORD error;
00659     static char errbuf[PCAP_ERRBUF_SIZE+1];
00660     int errlen;
00661 
00662     error = GetLastError();
00663     FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, error, 0, errbuf,
00664         PCAP_ERRBUF_SIZE, NULL);
00665 
00666     /*
00667      * "FormatMessage()" "helpfully" sticks CR/LF at the end of the
00668      * message.  Get rid of it.
00669      */
00670     errlen = strlen(errbuf);
00671     if (errlen >= 2) {
00672         errbuf[errlen - 1] = '\0';
00673         errbuf[errlen - 2] = '\0';
00674     }
00675     return (errbuf);
00676 }
00677 #endif
00678 
00679 /*
00680  * Not all systems have strerror().
00681  */
00682 char *
00683 pcap_strerror(int errnum)
00684 {
00685 #ifdef HAVE_STRERROR
00686     return (strerror(errnum));
00687 #else
00688     extern int sys_nerr;
00689     extern const char *const sys_errlist[];
00690     static char ebuf[20];
00691 
00692     if ((unsigned int)errnum < sys_nerr)
00693         return ((char *)sys_errlist[errnum]);
00694     (void)snprintf(ebuf, sizeof ebuf, "Unknown error: %d", errnum);
00695     return(ebuf);
00696 #endif
00697 }
00698 
00699 int
00700 pcap_setfilter(pcap_t *p, struct bpf_program *fp)
00701 {
00702     return p->setfilter_op(p, fp);
00703 }
00704 
00705 int
00706 pcap_stats(pcap_t *p, struct pcap_stat *ps)
00707 {
00708     return p->stats_op(p, ps);
00709 }
00710 
00711 static int
00712 pcap_stats_dead(pcap_t *p, struct pcap_stat *ps)
00713 {
00714     snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
00715         "Statistics aren't available from a pcap_open_dead pcap_t");
00716     return (-1);
00717 }
00718 
00719 static void
00720 pcap_close_dead(pcap_t *p)
00721 {
00722     /* Nothing to do. */
00723 }
00724 
00725 pcap_t *
00726 pcap_open_dead(int linktype, int snaplen)
00727 {
00728     pcap_t *p;
00729 
00730     p = malloc(sizeof(*p));
00731     if (p == NULL)
00732         return NULL;
00733     memset (p, 0, sizeof(*p));
00734     p->snapshot = snaplen;
00735     p->linktype = linktype;
00736     p->stats_op = pcap_stats_dead;
00737     p->close_op = pcap_close_dead;
00738     return p;
00739 }
00740 
00741 void
00742 pcap_close(pcap_t *p)
00743 {
00744     p->close_op(p);
00745     if (p->dlt_list != NULL)
00746         free(p->dlt_list);
00747     pcap_freecode(&p->fcode);
00748     free(p);
00749 }
00750 
00751 /*
00752  * We make the version string static, and return a pointer to it, rather
00753  * than exporting the version string directly.  On at least some UNIXes,
00754  * if you import data from a shared library into an program, the data is
00755  * bound into the program binary, so if the string in the version of the
00756  * library with which the program was linked isn't the same as the
00757  * string in the version of the library with which the program is being
00758  * run, various undesirable things may happen (warnings, the string
00759  * being the one from the version of the library with which the program
00760  * was linked, or even weirder things, such as the string being the one
00761  * from the library but being truncated).
00762  */
00763 #ifdef WIN32
00764 /*
00765  * XXX - it'd be nice if we could somehow generate the WinPcap and libpcap
00766  * version numbers when building WinPcap.  (It'd be nice to do so for
00767  * the packet.dll version number as well.)
00768  */
00769 static const char wpcap_version_string[] = "3.1 beta2";
00770 static const char pcap_version_string_fmt[] =
00771     "WinPcap version %s, based on libpcap version 0.8.1";
00772 static const char pcap_version_string_packet_dll_fmt[] =
00773     "WinPcap version %s (packet.dll version %s), based on libpcap version 0.8.1";
00774 static char *pcap_version_string;
00775 
00776 const char *
00777 pcap_lib_version(void)
00778 {
00779     char *packet_version_string;
00780     size_t pcap_version_string_len;
00781 
00782     if (pcap_version_string == NULL) {
00783         /*
00784          * Generate the version string.
00785          */
00786         packet_version_string = PacketGetVersion();
00787         if (strcmp(wpcap_version_string, packet_version_string) == 0) {
00788             /*
00789              * WinPcap version string and packet.dll version
00790              * string are the same; just report the WinPcap
00791              * version.
00792              */
00793             pcap_version_string_len =
00794                 (sizeof pcap_version_string_fmt - 2) +
00795                 strlen(wpcap_version_string);
00796             pcap_version_string = malloc(pcap_version_string_len);
00797             sprintf(pcap_version_string, pcap_version_string_fmt,
00798                 wpcap_version_string);
00799         } else {
00800             /*
00801              * WinPcap version string and packet.dll version
00802              * string are different; that shouldn't be the
00803              * case (the two libraries should come from the
00804              * same version of WinPcap), so we report both
00805              * versions.
00806              */
00807             pcap_version_string_len =
00808                 (sizeof pcap_version_string_packet_dll_fmt - 4) +
00809                 strlen(wpcap_version_string) +
00810                 strlen(packet_version_string);
00811             pcap_version_string = malloc(pcap_version_string_len);
00812             sprintf(pcap_version_string,
00813                 pcap_version_string_packet_dll_fmt,
00814                 wpcap_version_string, packet_version_string);
00815         }
00816     }
00817     return (pcap_version_string);
00818 }
00819 #else
00820 #include "version.h"
00821 
00822 const char *
00823 pcap_lib_version(void)
00824 {
00825     return (pcap_version_string);
00826 }
00827 #endif

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