X-Git-Url: https://git.tcpdump.org/tcpdump/blobdiff_plain/b6c8d27c478febe5b96a55c2c99d7cd0e7f34baf..5c77a341d4e766eef8beebaecd9e69bd2cc7b59b:/tcpdump.c diff --git a/tcpdump.c b/tcpdump.c index a3fce525..4dc2fe0a 100644 --- a/tcpdump.c +++ b/tcpdump.c @@ -30,7 +30,7 @@ static const char copyright[] _U_ = "@(#) Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 2000\n\ The Regents of the University of California. All rights reserved.\n"; static const char rcsid[] _U_ = - "@(#) $Header: /tcpdump/master/tcpdump/tcpdump.c,v 1.226 2004-01-22 09:35:50 hannes Exp $ (LBL)"; + "@(#) $Header: /tcpdump/master/tcpdump/tcpdump.c,v 1.235 2004-03-17 19:40:42 guy Exp $ (LBL)"; #endif /* @@ -78,11 +78,11 @@ extern int SIZE_BUF; int dflag; /* print filter code */ int eflag; /* print ethernet header */ int fflag; /* don't translate "foreign" IP address */ -int Lflag; /* list available data link types and exit */ +static int Lflag; /* list available data link types and exit */ int nflag; /* leave addresses as numbers */ int Nflag; /* remove domains from printed host names */ -int Oflag = 1; /* run filter code optimizer */ -int pflag; /* don't go promiscuous */ +static int Oflag = 1; /* run filter code optimizer */ +static int pflag; /* don't go promiscuous */ int qflag; /* quick (shorter) output */ int Rflag = 1; /* print sequence # field in AH/ESP*/ int sflag = 0; /* use the libsmi to translate OIDs */ @@ -93,9 +93,20 @@ int uflag = 0; /* Print undecoded NFS handles */ int vflag; /* verbose */ int xflag; /* print packet in hex */ int Xflag; /* print packet in ascii as well as hex */ -off_t Cflag = 0; /* rotate dump files after this many bytes */ +static off_t Cflag = 0; /* rotate dump files after this many bytes */ int Aflag = 0; /* print packet only in ascii observing LF, CR, TAB, SPACE */ -int dlt = -1; /* if != -1, ask libpcap for the DLT it names */ +static int dlt = -1; /* if != -1, ask libpcap for the DLT it names */ +static int Cflag_count = 0; /* Keep track of which file number we're writing */ +static int Wflag = 0; /* recycle output files after this number of files */ +static int WflagChars = 0; + +/* + * Define the maximum number of files for the -C flag, and how many + * characters can be added to a filename for the -C flag (which + * should be enough to handle MAX_CFLAG - 1). + */ +#define MAX_CFLAG 1000000 +#define MAX_CFLAG_CHARS 6 const char *dlt_name = NULL; @@ -118,7 +129,7 @@ static void show_dlts_and_exit(pcap_t *pd) __attribute__((noreturn)); static void print_packet(u_char *, const struct pcap_pkthdr *, const u_char *); static void dump_packet_and_trunc(u_char *, const struct pcap_pkthdr *, const u_char *); static void dump_packet(u_char *, const struct pcap_pkthdr *, const u_char *); -static void droproot(const char *); +static void droproot(const char *, const char *); #ifdef SIGINFO RETSIGTYPE requestinfo(int); @@ -220,6 +231,12 @@ static struct printer printers[] = { #endif #ifdef DLT_ENC { enc_if_print, DLT_ENC }, +#endif +#ifdef DLT_SYMANTEC_FIREWALL + { symantec_if_print, DLT_SYMANTEC_FIREWALL }, +#endif +#ifdef DLT_APPLE_IP_OVER_IEEE1394 + { ap1394_if_print, DLT_APPLE_IP_OVER_IEEE1394 }, #endif { NULL, 0 }, }; @@ -313,13 +330,26 @@ show_dlts_and_exit(pcap_t *pd) #define U_FLAG #endif -/* Drop root privileges */ -void droproot(const char *username) +/* Drop root privileges and chroot if necessary */ +static void +droproot(const char *username, const char *chroot_dir) { struct passwd *pw = NULL; + + if (chroot_dir && !username) { + fprintf(stderr, "Chroot without dropping root is insecure\n"); + exit(1); + } + pw = getpwnam(username); if (pw) { - if (initgroups(pw->pw_name, 0) != 0 || setgid(pw->pw_gid) != 0 || + if (chroot_dir) { + if (chroot(chroot_dir) != 0 || chdir ("/") != 0) { + fprintf(stderr, "Couldn't chroot/chdir to '%.64s'\n", chroot_dir); + exit(1); + } + } + if (initgroups(pw->pw_name, pw->pw_gid) != 0 || setgid(pw->pw_gid) != 0 || setuid(pw->pw_uid) != 0) { fprintf(stderr, "Couldn't change to '%.32s' uid=%d gid=%d\n", username, pw->pw_uid, pw->pw_gid); @@ -332,12 +362,36 @@ void droproot(const char *username) } } +static int +getWflagChars(int x) +{ + int c = 0; + + x -= 1; + while (x > 0) { + c += 1; + x /= 10; + } + + return c; +} + + +static void +MakeFilename(char *buffer, char *orig_name, int cnt, int max_chars) +{ + if (cnt == 0 && max_chars == 0) + strcpy(buffer, orig_name); + else + sprintf(buffer, "%s%0*d", orig_name, max_chars, cnt); +} + int main(int argc, char **argv) { register int cnt, op, i; bpf_u_int32 localnet, netmask; - register char *cp, *infile, *cmdbuf, *device, *RFileName, *WFileName; + register char *cp, *infile, *cmdbuf, *device, *RFileName, *WFileName, *WFileNameAlt; pcap_handler callback; int type; struct bpf_program fcode; @@ -349,6 +403,7 @@ main(int argc, char **argv) u_char *pcap_userdata; char ebuf[PCAP_ERRBUF_SIZE]; char *username = NULL; + char *chroot_dir = NULL; #ifdef HAVE_PCAP_FINDALLDEVS pcap_if_t *devpointer; int devnum; @@ -378,7 +433,7 @@ main(int argc, char **argv) opterr = 0; while ( - (op = getopt(argc, argv, "aA" B_FLAG "c:C:d" D_FLAG "eE:fF:i:lLm:nNOpqr:Rs:StT:u" U_FLAG "vw:xXy:YZ:")) != -1) + (op = getopt(argc, argv, "aA" B_FLAG "c:C:d" D_FLAG "eE:fF:i:lLm:nNOpqr:Rs:StT:u" U_FLAG "vw:W:xXy:YZ:")) != -1) switch (op) { case 'a': @@ -612,6 +667,13 @@ main(int argc, char **argv) WFileName = optarg; break; + case 'W': + Wflag = atoi(optarg); + if (Wflag < 0) + error("invalid number of output files %s", optarg); + WflagChars = getWflagChars(Wflag); + break; + case 'x': ++xflag; break; @@ -660,6 +722,24 @@ main(int argc, char **argv) if (tflag > 0) thiszone = gmt2local(0); +#ifdef WITH_CHROOT + /* if run as root, prepare for chrooting */ + if (getuid() == 0 || geteuid() == 0) { + /* future extensibility for cmd-line arguments */ + if (!chroot_dir) + chroot_dir = WITH_CHROOT; + } +#endif + +#ifdef WITH_USER + /* if run as root, prepare for dropping root privileges */ + if (getuid() == 0 || geteuid() == 0) { + /* Run with '-Z root' to restore old behaviour */ + if (!username) + username = WITH_USER; + } +#endif + if (RFileName != NULL) { int dlt; const char *dlt_name; @@ -674,13 +754,8 @@ main(int argc, char **argv) * people's trace files (especially if we're set-UID * root). */ - if (username) { - droproot(username); - } - else { - if (setgid(getgid()) != 0 || setuid(getuid()) != 0 ) - fprintf(stderr, "Warning: setgid/setuid failed !\n"); - } + if (setgid(getgid()) != 0 || setuid(getuid()) != 0 ) + fprintf(stderr, "Warning: setgid/setuid failed !\n"); #endif /* WIN32 */ pd = pcap_open_offline(RFileName, ebuf); if (pd == NULL) @@ -727,6 +802,13 @@ main(int argc, char **argv) error("%s", ebuf); else if (*ebuf) warning("%s", ebuf); + /* + * Let user own process after socket has been opened. + */ +#ifndef WIN32 + if (setgid(getgid()) != 0 || setuid(getuid()) != 0) + fprintf(stderr, "Warning: setgid/setuid failed !\n"); +#endif /* WIN32 */ #ifdef WIN32 if(UserBufferSize != 1000000) if(pcap_setbuff(pd, UserBufferSize)==-1){ @@ -764,18 +846,6 @@ main(int argc, char **argv) netmask = 0; warning("%s", ebuf); } - /* - * Let user own process after socket has been opened. - */ -#ifndef WIN32 - if (username) { - droproot(username); - } - else { - if (setgid(getgid()) != 0 || setuid(getuid()) != 0) - fprintf(stderr, "Warning: setgid/setuid failed !\n"); - } -#endif /* WIN32 */ } if (infile) cmdbuf = read_infile(infile); @@ -805,7 +875,13 @@ main(int argc, char **argv) if (pcap_setfilter(pd, &fcode) < 0) error("%s", pcap_geterr(pd)); if (WFileName) { - pcap_dumper_t *p = pcap_dump_open(pd, WFileName); + pcap_dumper_t *p; + + WFileNameAlt = (char *)malloc(strlen(WFileName) + MAX_CFLAG_CHARS + 1); + if (WFileNameAlt == NULL) + error("malloc of WFileNameAlt"); + MakeFilename(WFileNameAlt, WFileName, 0, WflagChars); + p = pcap_dump_open(pd, WFileNameAlt); if (p == NULL) error("%s", pcap_geterr(pd)); if (Cflag != 0) { @@ -831,6 +907,16 @@ main(int argc, char **argv) callback = print_packet; pcap_userdata = (u_char *)&printinfo; } +#ifndef WIN32 + /* + * We cannot do this earlier, because we want to be able to open + * the file (if done) for writing before giving up permissions. + */ + if (getuid() == 0 || geteuid() == 0) { + if (username || chroot_dir) + droproot(username, chroot_dir); + } +#endif /* WIN32 */ #ifdef SIGINFO (void)setsignal(SIGINFO, requestinfo); #endif @@ -977,38 +1063,10 @@ info(register int verbose) infoprint = 0; } -static void -reverse(char *s) -{ - int i, j, c; - - for (i = 0, j = strlen(s) - 1; i < j; i++, j--) { - c = s[i]; - s[i] = s[j]; - s[j] = c; - } -} - - -static void -swebitoa(unsigned int n, char *s) -{ - unsigned int i; - - i = 0; - do { - s[i++] = n % 10 + '0'; - } while ((n /= 10) > 0); - - s[i] = '\0'; - reverse(s); -} - static void dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *sp) { struct dump_info *dump_info; - static uint cnt = 2; char *name; ++packets_captured; @@ -1023,13 +1081,22 @@ dump_packet_and_trunc(u_char *user, const struct pcap_pkthdr *h, const u_char *s * file could put it over Cflag. */ if (ftell((FILE *)dump_info->p) > Cflag) { - name = (char *) malloc(strlen(dump_info->WFileName) + 4); + /* + * Close the current file and open a new one. + */ + pcap_dump_close(dump_info->p); + Cflag_count++; + if (Wflag > 0) { + if (Cflag_count >= Wflag) + Cflag_count = 0; + } else { + if (Cflag_count >= MAX_CFLAG) + error("too many output files"); + } + name = (char *)malloc(strlen(dump_info->WFileName) + MAX_CFLAG_CHARS + 1); if (name == NULL) error("dump_packet_and_trunc: malloc"); - strcpy(name, dump_info->WFileName); - swebitoa(cnt, name + strlen(dump_info->WFileName)); - cnt++; - pcap_dump_close(dump_info->p); + MakeFilename(name, dump_info->WFileName, Cflag_count, WflagChars); dump_info->p = pcap_dump_open(dump_info->pd, name); free(name); if (dump_info->p == NULL) @@ -1212,7 +1279,9 @@ usage(void) (void)fprintf(stderr, "\t\t[ -E algo:secret ] [ -F file ] [ -i interface ] [ -r file ]\n"); (void)fprintf(stderr, -"\t\t[ -s snaplen ] [ -T type ] [ -w file ] [ -y datalinktype ] [ -Z user ]\n"); +"\t\t[ -s snaplen ] [ -T type ] [ -w file ] [ -W filecount ]\n"); + (void)fprintf(stderr, +"\t\t[ -y datalinktype ] [ -Z user ]\n"); (void)fprintf(stderr, "\t\t[ expression ]\n"); exit(1);