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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     for (;;) {
00097         if (p->sf.rfile != NULL) {
00098             /*
00099              * 0 means EOF, so don't loop if we get 0.
00100              */
00101             n = pcap_offline_read(p, cnt, callback, user);
00102         } else {
00103             /*
00104              * XXX keep reading until we get something
00105              * (or an error occurs)
00106              */
00107             do {
00108                 n = p->read_op(p, cnt, callback, user);
00109             } while (n == 0);
00110         }
00111         if (n <= 0)
00112             return (n);
00113         if (cnt > 0) {
00114             cnt -= n;
00115             if (cnt <= 0)
00116                 return (0);
00117         }
00118     }
00119 }
00120 
00121 struct singleton {
00122     struct pcap_pkthdr *hdr;
00123     const u_char *pkt;
00124 };
00125 
00126 
00127 static void
00128 pcap_oneshot(u_char *userData, const struct pcap_pkthdr *h, const u_char *pkt)
00129 {
00130     struct singleton *sp = (struct singleton *)userData;
00131     *sp->hdr = *h;
00132     sp->pkt = pkt;
00133 }
00134 
00135 const u_char *
00136 pcap_next(pcap_t *p, struct pcap_pkthdr *h)
00137 {
00138     struct singleton s;
00139 
00140     s.hdr = h;
00141     if (pcap_dispatch(p, 1, pcap_oneshot, (u_char*)&s) <= 0)
00142         return (0);
00143     return (s.pkt);
00144 }
00145 
00146 struct pkt_for_fakecallback {
00147     struct pcap_pkthdr *hdr;
00148     const u_char **pkt;
00149 };
00150 
00151 static void
00152 pcap_fakecallback(u_char *userData, const struct pcap_pkthdr *h,
00153     const u_char *pkt)
00154 {
00155     struct pkt_for_fakecallback *sp = (struct pkt_for_fakecallback *)userData;
00156 
00157     *sp->hdr = *h;
00158     *sp->pkt = pkt;
00159 }
00160 
00161 int 
00162 pcap_next_ex(pcap_t *p, struct pcap_pkthdr **pkt_header,
00163     const u_char **pkt_data)
00164 {
00165     struct pkt_for_fakecallback s;
00166 
00167     s.hdr = &p->pcap_header;
00168     s.pkt = pkt_data;
00169 
00170     /* Saves a pointer to the packet headers */
00171     *pkt_header= &p->pcap_header;
00172 
00173 #ifdef HAVE_REMOTE
00174     /* Checks the capture type */
00175     if (p->rmt_clientside)
00176     {
00177         /* We are on an remote capture */
00178         if (!p->rmt_capstarted)
00179         {
00180             // if the capture has not started yet, please start it
00181             if (pcap_startcapture_remote(p) )
00182                 return -1;
00183         }
00184 
00185         return pcap_read_nocb_remote(p, pkt_header, (u_char **) pkt_data);
00186     }
00187 #endif /* HAVE_REMOTE */
00188 
00189     if (p->sf.rfile != NULL) {
00190         int status;
00191 
00192         /* We are on an offline capture */
00193         status = pcap_offline_read(p, 1, pcap_fakecallback,
00194             (u_char *)&s);
00195 
00196         /*
00197          * Return codes for pcap_offline_read() are:
00198          *   -  0: EOF
00199          *   - -1: error
00200          *   - >1: OK
00201          * The first one ('0') conflicts with the return code of
00202          * 0 from pcap_read() meaning "no packets arrived before
00203          * the timeout expired", so we map it to -2 so you can
00204          * distinguish between an EOF from a savefile and a
00205          * "no packets arrived before the timeout expired, try
00206          * again" from a live capture.
00207          */
00208         if (status == 0)
00209             return (-2);
00210         else
00211             return (status);
00212     }
00213 
00214     /*
00215      * Return codes for pcap_read() are:
00216      *   -  0: timeout
00217      *   - -1: error
00218      *   - -2: loop was broken out of with pcap_breakloop()
00219      *   - >1: OK
00220      * The first one ('0') conflicts with the return code of 0 from
00221      * pcap_offline_read() meaning "end of file".
00222     */
00223     return (p->read_op(p, 1, pcap_fakecallback, (u_char *)&s));
00224 }
00225 
00226 /*
00227  * Force the loop in "pcap_read()" or "pcap_read_offline()" to terminate.
00228  */
00229 void
00230 pcap_breakloop(pcap_t *p)
00231 {
00232     p->break_loop = 1;
00233 }
00234 
00235 int
00236 pcap_datalink(pcap_t *p)
00237 {
00238     return (p->linktype);
00239 }
00240 
00241 int
00242 pcap_list_datalinks(pcap_t *p, int **dlt_buffer)
00243 {
00244     if (p->dlt_count == 0) {
00245         /*
00246          * We couldn't fetch the list of DLTs, which means
00247          * this platform doesn't support changing the
00248          * DLT for an interface.  Return a list of DLTs
00249          * containing only the DLT this device supports.
00250          */
00251         *dlt_buffer = (int*)malloc(sizeof(**dlt_buffer));
00252         if (*dlt_buffer == NULL) {
00253             (void)snprintf(p->errbuf, sizeof(p->errbuf),
00254                 "malloc: %s", pcap_strerror(errno));
00255             return (-1);
00256         }
00257         **dlt_buffer = p->linktype;
00258         return (1);
00259     } else {
00260         *dlt_buffer = (int*)malloc(sizeof(**dlt_buffer) * p->dlt_count);
00261         if (*dlt_buffer == NULL) {
00262             (void)snprintf(p->errbuf, sizeof(p->errbuf),
00263                 "malloc: %s", pcap_strerror(errno));
00264             return (-1);
00265         }
00266         (void)memcpy(*dlt_buffer, p->dlt_list,
00267             sizeof(**dlt_buffer) * p->dlt_count);
00268         return (p->dlt_count);
00269     }
00270 }
00271 
00272 int
00273 pcap_set_datalink(pcap_t *p, int dlt)
00274 {
00275     int i;
00276     const char *dlt_name;
00277 
00278     if (p->dlt_count == 0 || p->set_datalink_op == NULL) {
00279         /*
00280          * We couldn't fetch the list of DLTs, or we don't
00281          * have a "set datalink" operation, which means
00282          * this platform doesn't support changing the
00283          * DLT for an interface.  Check whether the new
00284          * DLT is the one this interface supports.
00285          */
00286         if (p->linktype != dlt)
00287             goto unsupported;
00288 
00289         /*
00290          * It is, so there's nothing we need to do here.
00291          */
00292         return (0);
00293     }
00294     for (i = 0; i < p->dlt_count; i++)
00295         if (p->dlt_list[i] == dlt)
00296             break;
00297     if (i >= p->dlt_count)
00298         goto unsupported;
00299     if (p->dlt_count == 2 && p->dlt_list[0] == DLT_EN10MB &&
00300         dlt == DLT_DOCSIS) {
00301         /*
00302          * This is presumably an Ethernet device, as the first
00303          * link-layer type it offers is DLT_EN10MB, and the only
00304          * other type it offers is DLT_DOCSIS.  That means that
00305          * we can't tell the driver to supply DOCSIS link-layer
00306          * headers - we're just pretending that's what we're
00307          * getting, as, presumably, we're capturing on a dedicated
00308          * link to a Cisco Cable Modem Termination System, and
00309          * it's putting raw DOCSIS frames on the wire inside low-level
00310          * Ethernet framing.
00311          */
00312         p->linktype = dlt;
00313         return (0);
00314     }
00315     if (p->set_datalink_op(p, dlt) == -1)
00316         return (-1);
00317     p->linktype = dlt;
00318     return (0);
00319 
00320 unsupported:
00321     dlt_name = pcap_datalink_val_to_name(dlt);
00322     if (dlt_name != NULL) {
00323         (void) snprintf(p->errbuf, sizeof(p->errbuf),
00324             "%s is not one of the DLTs supported by this device",
00325             dlt_name);
00326     } else {
00327         (void) snprintf(p->errbuf, sizeof(p->errbuf),
00328             "DLT %d is not one of the DLTs supported by this device",
00329             dlt);
00330     }
00331     return (-1);
00332 }
00333 
00334 struct dlt_choice {
00335     const char *name;
00336     const char *description;
00337     int dlt;
00338 };
00339 
00340 #define DLT_CHOICE(code, description) { #code, description, code }
00341 #define DLT_CHOICE_SENTINEL { NULL, NULL, 0 }
00342 
00343 static struct dlt_choice dlt_choices[] = {
00344     DLT_CHOICE(DLT_NULL, "BSD loopback"),
00345     DLT_CHOICE(DLT_EN10MB, "Ethernet"),
00346     DLT_CHOICE(DLT_IEEE802, "Token ring"),
00347     DLT_CHOICE(DLT_ARCNET, "ARCNET"),
00348     DLT_CHOICE(DLT_SLIP, "SLIP"),
00349     DLT_CHOICE(DLT_PPP, "PPP"),
00350     DLT_CHOICE(DLT_FDDI, "FDDI"),
00351     DLT_CHOICE(DLT_ATM_RFC1483, "RFC 1483 IP-over-ATM"),
00352     DLT_CHOICE(DLT_RAW, "Raw IP"),
00353     DLT_CHOICE(DLT_SLIP_BSDOS, "BSD/OS SLIP"),
00354     DLT_CHOICE(DLT_PPP_BSDOS, "BSD/OS PPP"),
00355     DLT_CHOICE(DLT_ATM_CLIP, "Linux Classical IP-over-ATM"),
00356     DLT_CHOICE(DLT_PPP_SERIAL, "PPP over serial"),
00357     DLT_CHOICE(DLT_PPP_ETHER, "PPPoE"),
00358     DLT_CHOICE(DLT_C_HDLC, "Cisco HDLC"),
00359     DLT_CHOICE(DLT_IEEE802_11, "802.11"),
00360     DLT_CHOICE(DLT_FRELAY, "Frame Relay"),
00361     DLT_CHOICE(DLT_LOOP, "OpenBSD loopback"),
00362     DLT_CHOICE(DLT_ENC, "OpenBSD encapsulated IP"),
00363     DLT_CHOICE(DLT_LINUX_SLL, "Linux cooked"),
00364     DLT_CHOICE(DLT_LTALK, "Localtalk"),
00365     DLT_CHOICE(DLT_PFLOG, "OpenBSD pflog file"),
00366     DLT_CHOICE(DLT_PRISM_HEADER, "802.11 plus Prism header"),
00367     DLT_CHOICE(DLT_IP_OVER_FC, "RFC 2625 IP-over-Fibre Channel"),
00368     DLT_CHOICE(DLT_SUNATM, "Sun raw ATM"),
00369     DLT_CHOICE(DLT_IEEE802_11_RADIO, "802.11 plus radio information header"),
00370     DLT_CHOICE(DLT_ARCNET_LINUX, "Linux ARCNET"),
00371     DLT_CHOICE(DLT_DOCSIS, "DOCSIS"),
00372     DLT_CHOICE(DLT_LINUX_IRDA, "Linux IrDA"),
00373     DLT_CHOICE_SENTINEL
00374 };
00375 
00376 /*
00377  * This array is designed for mapping upper and lower case letter
00378  * together for a case independent comparison.  The mappings are
00379  * based upon ascii character sequences.
00380  */
00381 static const u_char charmap[] = {
00382     (u_char)'\000', (u_char)'\001', (u_char)'\002', (u_char)'\003',
00383     (u_char)'\004', (u_char)'\005', (u_char)'\006', (u_char)'\007',
00384     (u_char)'\010', (u_char)'\011', (u_char)'\012', (u_char)'\013',
00385     (u_char)'\014', (u_char)'\015', (u_char)'\016', (u_char)'\017',
00386     (u_char)'\020', (u_char)'\021', (u_char)'\022', (u_char)'\023',
00387     (u_char)'\024', (u_char)'\025', (u_char)'\026', (u_char)'\027',
00388     (u_char)'\030', (u_char)'\031', (u_char)'\032', (u_char)'\033',
00389     (u_char)'\034', (u_char)'\035', (u_char)'\036', (u_char)'\037',
00390     (u_char)'\040', (u_char)'\041', (u_char)'\042', (u_char)'\043',
00391     (u_char)'\044', (u_char)'\045', (u_char)'\046', (u_char)'\047',
00392     (u_char)'\050', (u_char)'\051', (u_char)'\052', (u_char)'\053',
00393     (u_char)'\054', (u_char)'\055', (u_char)'\056', (u_char)'\057',
00394     (u_char)'\060', (u_char)'\061', (u_char)'\062', (u_char)'\063',
00395     (u_char)'\064', (u_char)'\065', (u_char)'\066', (u_char)'\067',
00396     (u_char)'\070', (u_char)'\071', (u_char)'\072', (u_char)'\073',
00397     (u_char)'\074', (u_char)'\075', (u_char)'\076', (u_char)'\077',
00398     (u_char)'\100', (u_char)'\141', (u_char)'\142', (u_char)'\143',
00399     (u_char)'\144', (u_char)'\145', (u_char)'\146', (u_char)'\147',
00400     (u_char)'\150', (u_char)'\151', (u_char)'\152', (u_char)'\153',
00401     (u_char)'\154', (u_char)'\155', (u_char)'\156', (u_char)'\157',
00402     (u_char)'\160', (u_char)'\161', (u_char)'\162', (u_char)'\163',
00403     (u_char)'\164', (u_char)'\165', (u_char)'\166', (u_char)'\167',
00404     (u_char)'\170', (u_char)'\171', (u_char)'\172', (u_char)'\133',
00405     (u_char)'\134', (u_char)'\135', (u_char)'\136', (u_char)'\137',
00406     (u_char)'\140', (u_char)'\141', (u_char)'\142', (u_char)'\143',
00407     (u_char)'\144', (u_char)'\145', (u_char)'\146', (u_char)'\147',
00408     (u_char)'\150', (u_char)'\151', (u_char)'\152', (u_char)'\153',
00409     (u_char)'\154', (u_char)'\155', (u_char)'\156', (u_char)'\157',
00410     (u_char)'\160', (u_char)'\161', (u_char)'\162', (u_char)'\163',
00411     (u_char)'\164', (u_char)'\165', (u_char)'\166', (u_char)'\167',
00412     (u_char)'\170', (u_char)'\171', (u_char)'\172', (u_char)'\173',
00413     (u_char)'\174', (u_char)'\175', (u_char)'\176', (u_char)'\177',
00414     (u_char)'\200', (u_char)'\201', (u_char)'\202', (u_char)'\203',
00415     (u_char)'\204', (u_char)'\205', (u_char)'\206', (u_char)'\207',
00416     (u_char)'\210', (u_char)'\211', (u_char)'\212', (u_char)'\213',
00417     (u_char)'\214', (u_char)'\215', (u_char)'\216', (u_char)'\217',
00418     (u_char)'\220', (u_char)'\221', (u_char)'\222', (u_char)'\223',
00419     (u_char)'\224', (u_char)'\225', (u_char)'\226', (u_char)'\227',
00420     (u_char)'\230', (u_char)'\231', (u_char)'\232', (u_char)'\233',
00421     (u_char)'\234', (u_char)'\235', (u_char)'\236', (u_char)'\237',
00422     (u_char)'\240', (u_char)'\241', (u_char)'\242', (u_char)'\243',
00423     (u_char)'\244', (u_char)'\245', (u_char)'\246', (u_char)'\247',
00424     (u_char)'\250', (u_char)'\251', (u_char)'\252', (u_char)'\253',
00425     (u_char)'\254', (u_char)'\255', (u_char)'\256', (u_char)'\257',
00426     (u_char)'\260', (u_char)'\261', (u_char)'\262', (u_char)'\263',
00427     (u_char)'\264', (u_char)'\265', (u_char)'\266', (u_char)'\267',
00428     (u_char)'\270', (u_char)'\271', (u_char)'\272', (u_char)'\273',
00429     (u_char)'\274', (u_char)'\275', (u_char)'\276', (u_char)'\277',
00430     (u_char)'\300', (u_char)'\341', (u_char)'\342', (u_char)'\343',
00431     (u_char)'\344', (u_char)'\345', (u_char)'\346', (u_char)'\347',
00432     (u_char)'\350', (u_char)'\351', (u_char)'\352', (u_char)'\353',
00433     (u_char)'\354', (u_char)'\355', (u_char)'\356', (u_char)'\357',
00434     (u_char)'\360', (u_char)'\361', (u_char)'\362', (u_char)'\363',
00435     (u_char)'\364', (u_char)'\365', (u_char)'\366', (u_char)'\367',
00436     (u_char)'\370', (u_char)'\371', (u_char)'\372', (u_char)'\333',
00437     (u_char)'\334', (u_char)'\335', (u_char)'\336', (u_char)'\337',
00438     (u_char)'\340', (u_char)'\341', (u_char)'\342', (u_char)'\343',
00439     (u_char)'\344', (u_char)'\345', (u_char)'\346', (u_char)'\347',
00440     (u_char)'\350', (u_char)'\351', (u_char)'\352', (u_char)'\353',
00441     (u_char)'\354', (u_char)'\355', (u_char)'\356', (u_char)'\357',
00442     (u_char)'\360', (u_char)'\361', (u_char)'\362', (u_char)'\363',
00443     (u_char)'\364', (u_char)'\365', (u_char)'\366', (u_char)'\367',
00444     (u_char)'\370', (u_char)'\371', (u_char)'\372', (u_char)'\373',
00445     (u_char)'\374', (u_char)'\375', (u_char)'\376', (u_char)'\377',
00446 };
00447 
00448 int
00449 pcap_strcasecmp(const char *s1, const char *s2)
00450 {
00451     register const u_char   *cm = charmap,
00452                 *us1 = (u_char *)s1,
00453                 *us2 = (u_char *)s2;
00454 
00455     while (cm[*us1] == cm[*us2++])
00456         if (*us1++ == '\0')
00457             return(0);
00458     return (cm[*us1] - cm[*--us2]);
00459 }
00460 
00461 int
00462 pcap_datalink_name_to_val(const char *name)
00463 {
00464     int i;
00465 
00466     for (i = 0; dlt_choices[i].name != NULL; i++) {
00467         if (pcap_strcasecmp(dlt_choices[i].name + sizeof("DLT_") - 1,
00468             name) == 0)
00469             return (dlt_choices[i].dlt);
00470     }
00471     return (-1);
00472 }
00473 
00474 const char *
00475 pcap_datalink_val_to_name(int dlt)
00476 {
00477     int i;
00478 
00479     for (i = 0; dlt_choices[i].name != NULL; i++) {
00480         if (dlt_choices[i].dlt == dlt)
00481             return (dlt_choices[i].name + sizeof("DLT_") - 1);
00482     }
00483     return (NULL);
00484 }
00485 
00486 const char *
00487 pcap_datalink_val_to_description(int dlt)
00488 {
00489     int i;
00490 
00491     for (i = 0; dlt_choices[i].name != NULL; i++) {
00492         if (dlt_choices[i].dlt == dlt)
00493             return (dlt_choices[i].description);
00494     }
00495     return (NULL);
00496 }
00497 
00498 int
00499 pcap_snapshot(pcap_t *p)
00500 {
00501     return (p->snapshot);
00502 }
00503 
00504 int
00505 pcap_is_swapped(pcap_t *p)
00506 {
00507     return (p->sf.swapped);
00508 }
00509 
00510 int
00511 pcap_major_version(pcap_t *p)
00512 {
00513     return (p->sf.version_major);
00514 }
00515 
00516 int
00517 pcap_minor_version(pcap_t *p)
00518 {
00519     return (p->sf.version_minor);
00520 }
00521 
00522 FILE *
00523 pcap_file(pcap_t *p)
00524 {
00525     return (p->sf.rfile);
00526 }
00527 
00528 int
00529 pcap_fileno(pcap_t *p)
00530 {
00531 #ifdef HAVE_REMOTE
00532     if (p->rmt_clientside)
00533         return(p->rmt_sockdata);
00534 #endif /* HAVE_REMOTE */
00535 
00536 #ifndef WIN32
00537     return (p->fd);
00538 #else
00539     if (p->adapter != NULL)
00540         return ((int)(DWORD)p->adapter->hFile);
00541     else
00542         return (-1);
00543 #endif
00544 }
00545 
00546 #ifndef WIN32
00547 int
00548 pcap_get_selectable_fd(pcap_t *p)
00549 {
00550     return (p->selectable_fd);
00551 }
00552 #endif
00553 
00554 void
00555 pcap_perror(pcap_t *p, char *prefix)
00556 {
00557     fprintf(stderr, "%s: %s\n", prefix, p->errbuf);
00558 }
00559 
00560 char *
00561 pcap_geterr(pcap_t *p)
00562 {
00563     return (p->errbuf);
00564 }
00565 
00566 int
00567 pcap_getnonblock(pcap_t *p, char *errbuf)
00568 {
00569     return p->getnonblock_op(p, errbuf);
00570 }
00571 
00572 /*
00573  * Get the current non-blocking mode setting, under the assumption that
00574  * it's just the standard POSIX non-blocking flag.
00575  *
00576  * We don't look at "p->nonblock", in case somebody tweaked the FD
00577  * directly.
00578  */
00579 #ifndef WIN32
00580 int
00581 pcap_getnonblock_fd(pcap_t *p, char *errbuf)
00582 {
00583     int fdflags;
00584 
00585     fdflags = fcntl(p->fd, F_GETFL, 0);
00586     if (fdflags == -1) {
00587         snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "F_GETFL: %s",
00588             pcap_strerror(errno));
00589         return (-1);
00590     }
00591     if (fdflags & O_NONBLOCK)
00592         return (1);
00593     else
00594         return (0);
00595 }
00596 #endif
00597 
00598 int
00599 pcap_setnonblock(pcap_t *p, int nonblock, char *errbuf)
00600 {
00601     return p->setnonblock_op(p, nonblock, errbuf);
00602 }
00603 
00604 #ifndef WIN32
00605 /*
00606  * Set non-blocking mode, under the assumption that it's just the
00607  * standard POSIX non-blocking flag.  (This can be called by the
00608  * per-platform non-blocking-mode routine if that routine also
00609  * needs to do some additional work.)
00610  */
00611 int
00612 pcap_setnonblock_fd(pcap_t *p, int nonblock, char *errbuf)
00613 {
00614     int fdflags;
00615 
00616     fdflags = fcntl(p->fd, F_GETFL, 0);
00617     if (fdflags == -1) {
00618         snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "F_GETFL: %s",
00619             pcap_strerror(errno));
00620         return (-1);
00621     }
00622     if (nonblock)
00623         fdflags |= O_NONBLOCK;
00624     else
00625         fdflags &= ~O_NONBLOCK;
00626     if (fcntl(p->fd, F_SETFL, fdflags) == -1) {
00627         snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "F_SETFL: %s",
00628             pcap_strerror(errno));
00629         return (-1);
00630     }
00631     return (0);
00632 }
00633 #endif
00634 
00635 #ifdef WIN32
00636 /*
00637  * Generate a string for the last Win32-specific error (i.e. an error generated when 
00638  * calling a Win32 API).
00639  * For errors occurred during standard C calls, we still use pcap_strerror()
00640  */
00641 char *
00642 pcap_win32strerror(void)
00643 {
00644     DWORD error;
00645     static char errbuf[PCAP_ERRBUF_SIZE+1];
00646     int errlen;
00647 
00648     error = GetLastError();
00649     FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, error, 0, errbuf,
00650         PCAP_ERRBUF_SIZE, NULL);
00651 
00652     /*
00653      * "FormatMessage()" "helpfully" sticks CR/LF at the end of the
00654      * message.  Get rid of it.
00655      */
00656     errlen = strlen(errbuf);
00657     if (errlen >= 2) {
00658         errbuf[errlen - 1] = '\0';
00659         errbuf[errlen - 2] = '\0';
00660     }
00661     return (errbuf);
00662 }
00663 #endif
00664 
00665 /*
00666  * Not all systems have strerror().
00667  */
00668 char *
00669 pcap_strerror(int errnum)
00670 {
00671 #ifdef HAVE_STRERROR
00672     return (strerror(errnum));
00673 #else
00674     extern int sys_nerr;
00675     extern const char *const sys_errlist[];
00676     static char ebuf[20];
00677 
00678     if ((unsigned int)errnum < sys_nerr)
00679         return ((char *)sys_errlist[errnum]);
00680     (void)snprintf(ebuf, sizeof ebuf, "Unknown error: %d", errnum);
00681     return(ebuf);
00682 #endif
00683 }
00684 
00685 int
00686 pcap_setfilter(pcap_t *p, struct bpf_program *fp)
00687 {
00688     return p->setfilter_op(p, fp);
00689 }
00690 
00691 int
00692 pcap_stats(pcap_t *p, struct pcap_stat *ps)
00693 {
00694     return p->stats_op(p, ps);
00695 }
00696 
00697 static int
00698 pcap_stats_dead(pcap_t *p, struct pcap_stat *ps)
00699 {
00700     snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
00701         "Statistics aren't available from a pcap_open_dead pcap_t");
00702     return (-1);
00703 }
00704 
00705 static void
00706 pcap_close_dead(pcap_t *p)
00707 {
00708     /* Nothing to do. */
00709 }
00710 
00711 pcap_t *
00712 pcap_open_dead(int linktype, int snaplen)
00713 {
00714     pcap_t *p;
00715 
00716     p = malloc(sizeof(*p));
00717     if (p == NULL)
00718         return NULL;
00719     memset (p, 0, sizeof(*p));
00720     p->snapshot = snaplen;
00721     p->linktype = linktype;
00722     p->stats_op = pcap_stats_dead;
00723     p->close_op = pcap_close_dead;
00724     return p;
00725 }
00726 
00727 void
00728 pcap_close(pcap_t *p)
00729 {
00730     p->close_op(p);
00731     if (p->dlt_list != NULL)
00732         free(p->dlt_list);
00733     pcap_freecode(&p->fcode);
00734     free(p);
00735 }
00736 
00737 /*
00738  * We make the version string static, and return a pointer to it, rather
00739  * than exporting the version string directly.  On at least some UNIXes,
00740  * if you import data from a shared library into an program, the data is
00741  * bound into the program binary, so if the string in the version of the
00742  * library with which the program was linked isn't the same as the
00743  * string in the version of the library with which the program is being
00744  * run, various undesirable things may happen (warnings, the string
00745  * being the one from the version of the library with which the program
00746  * was linked, or even weirder things, such as the string being the one
00747  * from the library but being truncated).
00748  */
00749 #ifdef WIN32
00750 /*
00751  * XXX - it'd be nice if we could somehow generate the WinPcap and libpcap
00752  * version numbers when building WinPcap.  (It'd be nice to do so for
00753  * the packet.dll version number as well.)
00754  */
00755 static const char wpcap_version_string[] = "3.0";
00756 static const char pcap_version_string_fmt[] =
00757     "WinPcap version %s, based on libpcap version 0.8";
00758 static const char pcap_version_string_packet_dll_fmt[] =
00759     "WinPcap version %s (packet.dll version %s), based on libpcap version 0.8";
00760 static char *pcap_version_string;
00761 
00762 const char *
00763 pcap_lib_version(void)
00764 {
00765     char *packet_version_string;
00766     size_t pcap_version_string_len;
00767 
00768     if (pcap_version_string == NULL) {
00769         /*
00770          * Generate the version string.
00771          */
00772         packet_version_string = PacketGetVersion();
00773         if (strcmp(wpcap_version_string, packet_version_string) == 0) {
00774             /*
00775              * WinPcap version string and packet.dll version
00776              * string are the same; just report the WinPcap
00777              * version.
00778              */
00779             pcap_version_string_len =
00780                 (sizeof pcap_version_string_fmt - 2) +
00781                 strlen(wpcap_version_string);
00782             pcap_version_string = malloc(pcap_version_string_len);
00783             sprintf(pcap_version_string, pcap_version_string_fmt,
00784                 wpcap_version_string);
00785         } else {
00786             /*
00787              * WinPcap version string and packet.dll version
00788              * string are different; that shouldn't be the
00789              * case (the two libraries should come from the
00790              * same version of WinPcap), so we report both
00791              * versions.
00792              */
00793             pcap_version_string_len =
00794                 (sizeof pcap_version_string_packet_dll_fmt - 4) +
00795                 strlen(wpcap_version_string) +
00796                 strlen(packet_version_string);
00797             pcap_version_string = malloc(pcap_version_string_len);
00798             sprintf(pcap_version_string,
00799                 pcap_version_string_packet_dll_fmt,
00800                 wpcap_version_string, packet_version_string);
00801         }
00802     }
00803     return (pcap_version_string);
00804 }
00805 #else
00806 #include "version.h"
00807 
00808 const char *
00809 pcap_lib_version(void)
00810 {
00811     return (pcap_version_string);
00812 }
00813 #endif

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