From da13a5a9d72229b2a6026a49b9977934bdef13ed Mon Sep 17 00:00:00 2001 From: bms Date: Wed, 31 Mar 2004 09:07:39 +0000 Subject: Import libpcap 0.8.3, from http://www.tcpdump.org/releases/libpcap-0.8.3.tar.gz --- contrib/libpcap/pcap-bpf.c | 544 +++++++++++++++++++++++++++++++++++++++------ 1 file changed, 480 insertions(+), 64 deletions(-) (limited to 'contrib/libpcap/pcap-bpf.c') diff --git a/contrib/libpcap/pcap-bpf.c b/contrib/libpcap/pcap-bpf.c index 6d74af7..5b0eab6 100644 --- a/contrib/libpcap/pcap-bpf.c +++ b/contrib/libpcap/pcap-bpf.c @@ -19,8 +19,8 @@ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. */ #ifndef lint -static const char rcsid[] = - "@(#) $Header: /tcpdump/master/libpcap/pcap-bpf.c,v 1.48 2001/12/10 07:14:14 guy Exp $ (LBL)"; +static const char rcsid[] _U_ = + "@(#) $Header: /tcpdump/master/libpcap/pcap-bpf.c,v 1.67.2.4 2003/11/22 00:06:28 guy Exp $ (LBL)"; #endif #ifdef HAVE_CONFIG_H @@ -33,18 +33,56 @@ static const char rcsid[] = #include #include #include +#include #include + #ifdef _AIX + +/* + * Make "pcap.h" not include "pcap-bpf.h"; we are going to include the + * native OS version, as we need "struct bpf_config" from it. + */ +#define PCAP_DONT_INCLUDE_PCAP_BPF_H + +#include + /* - * XXX - I'm guessing here AIX defines IFT_ values in , - * as BSD does. If not, this code won't compile, but, if not, you - * want to send us a bug report and fall back on using DLPI. - * It's not as if BPF used to work right on AIX before this change; - * this change attempts to fix the fact that it didn't.... + * Prevent bpf.h from redefining the DLT_ values to their + * IFT_ values, as we're going to return the standard libpcap + * values, not IBM's non-standard IFT_ values. */ +#undef _AIX +#include +#define _AIX + #include /* for IFT_ values */ -#endif +#include +#include +#include +#include + +#ifdef __64BIT__ +#define domakedev makedev64 +#define getmajor major64 +#define bpf_hdr bpf_hdr32 +#else /* __64BIT__ */ +#define domakedev makedev +#define getmajor major +#endif /* __64BIT__ */ + +#define BPF_NAME "bpf" +#define BPF_MINORS 4 +#define DRIVER_PATH "/usr/lib/drivers" +#define BPF_NODE "/dev/bpf" +static int bpfloadedflag = 0; +static int odmlockid = 0; + +#else /* _AIX */ + +#include + +#endif /* _AIX */ #include #include @@ -56,14 +94,21 @@ static const char rcsid[] = #include "pcap-int.h" +#ifdef HAVE_DAG_API +#include "pcap-dag.h" +#endif /* HAVE_DAG_API */ + #ifdef HAVE_OS_PROTO_H #include "os-proto.h" #endif -#include "gencode.h" +#include "gencode.h" /* for "no_optimize" */ -int -pcap_stats(pcap_t *p, struct pcap_stat *ps) +static int pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp); +static int pcap_set_datalink_bpf(pcap_t *p, int dlt); + +static int +pcap_stats_bpf(pcap_t *p, struct pcap_stat *ps) { struct bpf_stat s; @@ -91,14 +136,28 @@ pcap_stats(pcap_t *p, struct pcap_stat *ps) return (0); } -int -pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user) +static int +pcap_read_bpf(pcap_t *p, int cnt, pcap_handler callback, u_char *user) { int cc; int n = 0; register u_char *bp, *ep; + struct bpf_insn *fcode; + fcode = p->md.use_bpf ? NULL : p->fcode.bf_insns; again: + /* + * Has "pcap_breakloop()" been called? + */ + if (p->break_loop) { + /* + * Yes - clear the flag that indicates that it + * has, and return -2 to indicate that we were + * told to break out of the loop. + */ + p->break_loop = 0; + return (-2); + } cc = p->cc; if (p->cc == 0) { cc = read(p->fd, (char *)p->buffer, p->bufsize); @@ -109,6 +168,32 @@ pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user) case EINTR: goto again; +#ifdef _AIX + case EFAULT: + /* + * Sigh. More AIX wonderfulness. + * + * For some unknown reason the uiomove() + * operation in the bpf kernel extension + * used to copy the buffer into user + * space sometimes returns EFAULT. I have + * no idea why this is the case given that + * a kernel debugger shows the user buffer + * is correct. This problem appears to + * be mostly mitigated by the memset of + * the buffer before it is first used. + * Very strange.... Shaun Clowes + * + * In any case this means that we shouldn't + * treat EFAULT as a fatal error; as we + * don't have an API for returning + * a "some packets were dropped since + * the last packet you saw" indication, + * we just ignore EFAULT and keep reading. + */ + goto again; +#endif + case EWOULDBLOCK: return (0); #if defined(sun) && !defined(BSD) @@ -141,31 +226,65 @@ pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user) ep = bp + cc; while (bp < ep) { register int caplen, hdrlen; + + /* + * Has "pcap_breakloop()" been called? + * If so, return immediately - if we haven't read any + * packets, clear the flag and return -2 to indicate + * that we were told to break out of the loop, otherwise + * leave the flag set, so that the *next* call will break + * out of the loop without having read any packets, and + * return the number of packets we've processed so far. + */ + if (p->break_loop) { + if (n == 0) { + p->break_loop = 0; + return (-2); + } else { + p->bp = bp; + p->cc = ep - bp; + return (n); + } + } + caplen = bhp->bh_caplen; hdrlen = bhp->bh_hdrlen; /* - * XXX A bpf_hdr matches a pcap_pkthdr. + * Short-circuit evaluation: if using BPF filter + * in kernel, no need to do it now. */ + if (fcode == NULL || + bpf_filter(fcode, bp + hdrlen, bhp->bh_datalen, caplen)) { #ifdef _AIX - /* - * AIX's BPF returns seconds/nanoseconds time stamps, not - * seconds/microseconds time stamps. - * - * XXX - I'm guessing here that it's a "struct timestamp"; - * if not, this code won't compile, but, if not, you - * want to send us a bug report and fall back on using - * DLPI. It's not as if BPF used to work right on - * AIX before this change; this change attempts to fix - * the fact that it didn't.... - */ - bhp->bh_tstamp.tv_usec = bhp->bh_tstamp.tv_usec/1000; + /* + * AIX's BPF returns seconds/nanoseconds time + * stamps, not seconds/microseconds time stamps. + * + * XXX - I'm guessing here that it's a "struct + * timestamp"; if not, this code won't compile, + * but, if not, you want to send us a bug report + * and fall back on using DLPI. It's not as if + * BPF used to work right on AIX before this + * change; this change attempts to fix the fact + * that it didn't.... + */ + bhp->bh_tstamp.tv_usec = bhp->bh_tstamp.tv_usec/1000; #endif - (*callback)(user, (struct pcap_pkthdr*)bp, bp + hdrlen); - bp += BPF_WORDALIGN(caplen + hdrlen); - if (++n >= cnt && cnt > 0) { - p->bp = bp; - p->cc = ep - bp; - return (n); + /* + * XXX A bpf_hdr matches a pcap_pkthdr. + */ + (*callback)(user, (struct pcap_pkthdr*)bp, bp + hdrlen); + bp += BPF_WORDALIGN(caplen + hdrlen); + if (++n >= cnt && cnt > 0) { + p->bp = bp; + p->cc = ep - bp; + return (n); + } + } else { + /* + * Skip this packet. + */ + bp += BPF_WORDALIGN(caplen + hdrlen); } } #undef bhp @@ -173,6 +292,159 @@ pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user) return (n); } +#ifdef _AIX +static int +bpf_odminit(char *errbuf) +{ + char *errstr; + + if (odm_initialize() == -1) { + if (odm_err_msg(odmerrno, &errstr) == -1) + errstr = "Unknown error"; + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "bpf_load: odm_initialize failed: %s", + errstr); + return (-1); + } + + if ((odmlockid = odm_lock("/etc/objrepos/config_lock", ODM_WAIT)) == -1) { + if (odm_err_msg(odmerrno, &errstr) == -1) + errstr = "Unknown error"; + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "bpf_load: odm_lock of /etc/objrepos/config_lock failed: %s", + errstr); + return (-1); + } + + return (0); +} + +static int +bpf_odmcleanup(char *errbuf) +{ + char *errstr; + + if (odm_unlock(odmlockid) == -1) { + if (odm_err_msg(odmerrno, &errstr) == -1) + errstr = "Unknown error"; + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "bpf_load: odm_unlock failed: %s", + errstr); + return (-1); + } + + if (odm_terminate() == -1) { + if (odm_err_msg(odmerrno, &errstr) == -1) + errstr = "Unknown error"; + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "bpf_load: odm_terminate failed: %s", + errstr); + return (-1); + } + + return (0); +} + +static int +bpf_load(char *errbuf) +{ + long major; + int *minors; + int numminors, i, rc; + char buf[1024]; + struct stat sbuf; + struct bpf_config cfg_bpf; + struct cfg_load cfg_ld; + struct cfg_kmod cfg_km; + + /* + * This is very very close to what happens in the real implementation + * but I've fixed some (unlikely) bug situations. + */ + if (bpfloadedflag) + return (0); + + if (bpf_odminit(errbuf) != 0) + return (-1); + + major = genmajor(BPF_NAME); + if (major == -1) { + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "bpf_load: genmajor failed: %s", pcap_strerror(errno)); + return (-1); + } + + minors = getminor(major, &numminors, BPF_NAME); + if (!minors) { + minors = genminor("bpf", major, 0, BPF_MINORS, 1, 1); + if (!minors) { + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "bpf_load: genminor failed: %s", + pcap_strerror(errno)); + return (-1); + } + } + + if (bpf_odmcleanup(errbuf)) + return (-1); + + rc = stat(BPF_NODE "0", &sbuf); + if (rc == -1 && errno != ENOENT) { + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "bpf_load: can't stat %s: %s", + BPF_NODE "0", pcap_strerror(errno)); + return (-1); + } + + if (rc == -1 || getmajor(sbuf.st_rdev) != major) { + for (i = 0; i < BPF_MINORS; i++) { + sprintf(buf, "%s%d", BPF_NODE, i); + unlink(buf); + if (mknod(buf, S_IRUSR | S_IFCHR, domakedev(major, i)) == -1) { + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "bpf_load: can't mknod %s: %s", + buf, pcap_strerror(errno)); + return (-1); + } + } + } + + /* Check if the driver is loaded */ + memset(&cfg_ld, 0x0, sizeof(cfg_ld)); + cfg_ld.path = buf; + sprintf(cfg_ld.path, "%s/%s", DRIVER_PATH, BPF_NAME); + if ((sysconfig(SYS_QUERYLOAD, (void *)&cfg_ld, sizeof(cfg_ld)) == -1) || + (cfg_ld.kmid == 0)) { + /* Driver isn't loaded, load it now */ + if (sysconfig(SYS_SINGLELOAD, (void *)&cfg_ld, sizeof(cfg_ld)) == -1) { + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "bpf_load: could not load driver: %s", + strerror(errno)); + return (-1); + } + } + + /* Configure the driver */ + cfg_km.cmd = CFG_INIT; + cfg_km.kmid = cfg_ld.kmid; + cfg_km.mdilen = sizeof(cfg_bpf); + cfg_km.mdiptr = (void *)&cfg_bpf; + for (i = 0; i < BPF_MINORS; i++) { + cfg_bpf.devno = domakedev(major, i); + if (sysconfig(SYS_CFGKMOD, (void *)&cfg_km, sizeof(cfg_km)) == -1) { + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "bpf_load: could not configure driver: %s", + strerror(errno)); + return (-1); + } + } + + bpfloadedflag = 1; + + return (0); +} +#endif + static inline int bpf_open(pcap_t *p, char *errbuf) { @@ -180,6 +452,16 @@ bpf_open(pcap_t *p, char *errbuf) int n = 0; char device[sizeof "/dev/bpf0000000000"]; +#ifdef _AIX + /* + * Load the bpf driver, if it isn't already loaded, + * and create the BPF device entries, if they don't + * already exist. + */ + if (bpf_load(errbuf) == -1) + return (-1); +#endif + /* * Go through all the minors and find one that isn't in use. */ @@ -198,17 +480,48 @@ bpf_open(pcap_t *p, char *errbuf) return (fd); } +static void +pcap_close_bpf(pcap_t *p) +{ + if (p->buffer != NULL) + free(p->buffer); + if (p->fd >= 0) + close(p->fd); +} + +/* + * XXX - on AIX, IBM's tcpdump (and perhaps the incompatible-with-everybody- + * else's libpcap in AIX 5.1) appears to forcibly load the BPF driver + * if it's not already loaded, and to create the BPF devices if they + * don't exist. + * + * It'd be nice if we could do the same, although the code to do so + * might be version-dependent, alas (the way to do it isn't necessarily + * documented). + */ pcap_t * -pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf) +pcap_open_live(const char *device, int snaplen, int promisc, int to_ms, + char *ebuf) { int fd; struct ifreq ifr; struct bpf_version bv; +#ifdef BIOCGDLTLIST struct bpf_dltlist bdl; +#endif u_int v; pcap_t *p; + struct utsname osinfo; - bzero(&bdl, sizeof(bdl)); +#ifdef HAVE_DAG_API + if (strstr(device, "dag")) { + return dag_open_live(device, snaplen, promisc, to_ms, ebuf); + } +#endif /* HAVE_DAG_API */ + +#ifdef BIOCGDLTLIST + memset(&bdl, 0, sizeof(bdl)); +#endif p = (pcap_t *)malloc(sizeof(*p)); if (p == NULL) { @@ -239,12 +552,15 @@ pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf) /* * Try finding a good size for the buffer; 32768 may be too * big, so keep cutting it in half until we find a size - * that works, or run out of sizes to try. + * that works, or run out of sizes to try. If the default + * is larger, don't make it smaller. * * XXX - there should be a user-accessible hook to set the * initial buffer size. */ - for (v = 32768; v != 0; v >>= 1) { + if ((ioctl(fd, BIOCGBLEN, (caddr_t)&v) < 0) || v < 32768) + v = 32768; + for ( ; v != 0; v >>= 1) { /* Ignore the return value - this is because the call fails * on BPF systems that don't have kernel malloc. And if * the call fails, it's no big deal, we just continue to @@ -294,11 +610,15 @@ pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf) v = DLT_IEEE802; break; + case IFT_LOOP: + v = DLT_NULL; + break; + default: /* * We don't know what to map this to yet. */ - snprintf(ebuf, PCAP_ERRBUF_SIZE, "unknown interface type %lu", + snprintf(ebuf, PCAP_ERRBUF_SIZE, "unknown interface type %u", v); goto bad; } @@ -316,7 +636,7 @@ pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf) break; case 11: /*DLT_FR*/ - v = DLT_RAW; /*XXX*/ + v = DLT_FRELAY; break; case 12: /*DLT_C_HDLC*/ @@ -326,12 +646,13 @@ pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf) #endif p->linktype = v; +#ifdef BIOCGDLTLIST /* - * We know the default link type -- now determine any additional - * DLTs this interface supports. If this fails, it's not fatal; - * we just don't get to use the feature later. + * We know the default link type -- now determine all the DLTs + * this interface supports. If this fails with EINVAL, it's + * not fatal; we just don't get to use the feature later. */ - if (ioctl(fd, BIOCGDLTLIST, (caddr_t) &bdl) == 0) { + if (ioctl(fd, BIOCGDLTLIST, (caddr_t)&bdl) == 0) { bdl.bfl_list = (u_int *) malloc(sizeof(u_int) * bdl.bfl_len); if (bdl.bfl_list == NULL) { (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s", @@ -339,19 +660,30 @@ pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf) goto bad; } - if (ioctl(fd, BIOCGDLTLIST, (caddr_t) &bdl) < 0) { + if (ioctl(fd, BIOCGDLTLIST, (caddr_t)&bdl) < 0) { (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, "BIOCGDLTLIST: %s", pcap_strerror(errno)); - free(bdl.bfl_list); goto bad; } p->dlt_count = bdl.bfl_len; p->dlt_list = bdl.bfl_list; + } else { + if (errno != EINVAL) { + (void)snprintf(ebuf, PCAP_ERRBUF_SIZE, + "BIOCGDLTLIST: %s", pcap_strerror(errno)); + goto bad; + } } +#endif /* set timeout */ if (to_ms != 0) { + /* + * XXX - is this seconds/nanoseconds in AIX? + * (Treating it as such doesn't fix the timeout + * problem described below.) + */ struct timeval to; to.tv_sec = to_ms / 1000; to.tv_usec = (to_ms * 1000) % 1000000; @@ -439,18 +771,98 @@ pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf) pcap_strerror(errno)); goto bad; } +#ifdef _AIX + /* For some strange reason this seems to prevent the EFAULT + * problems we have experienced from AIX BPF. */ + memset(p->buffer, 0x0, p->bufsize); +#endif + + /* + * On most BPF platforms, either you can do a "select()" or + * "poll()" on a BPF file descriptor and it works correctly, + * or you can do it and it will return "readable" if the + * hold buffer is full but not if the timeout expires *and* + * a non-blocking read will, if the hold buffer is empty + * but the store buffer isn't empty, rotate the buffers + * and return what packets are available. + * + * In the latter case, the fact that a non-blocking read + * will give you the available packets means you can work + * around the failure of "select()" and "poll()" to wake up + * and return "readable" when the timeout expires by using + * the timeout as the "select()" or "poll()" timeout, putting + * the BPF descriptor into non-blocking mode, and read from + * it regardless of whether "select()" reports it as readable + * or not. + * + * However, in FreeBSD 4.3 and 4.4, "select()" and "poll()" + * won't wake up and return "readable" if the timer expires + * and non-blocking reads return EWOULDBLOCK if the hold + * buffer is empty, even if the store buffer is non-empty. + * + * This means the workaround in question won't work. + * + * Therefore, on FreeBSD 4.3 and 4.4, we set "p->selectable_fd" + * to -1, which means "sorry, you can't use 'select()' or 'poll()' + * here". On all other BPF platforms, we set it to the FD for + * the BPF device; in NetBSD, OpenBSD, and Darwin, a non-blocking + * read will, if the hold buffer is empty and the store buffer + * isn't empty, rotate the buffers and return what packets are + * there (and in sufficiently recent versions of OpenBSD + * "select()" and "poll()" should work correctly). + * + * XXX - what about AIX? + */ + if (uname(&osinfo) == 0) { + /* + * We can check what OS this is. + */ + if (strcmp(osinfo.sysname, "FreeBSD") == 0 && + (strcmp(osinfo.release, "4.3") == 0 || + strcmp(osinfo.release, "4.4") == 0)) + p->selectable_fd = -1; + else + p->selectable_fd = p->fd; + } else { + /* + * We can't find out what OS this is, so assume we can + * do a "select()" or "poll()". + */ + p->selectable_fd = p->fd; + } + + p->read_op = pcap_read_bpf; + p->setfilter_op = pcap_setfilter_bpf; + p->set_datalink_op = pcap_set_datalink_bpf; + p->getnonblock_op = pcap_getnonblock_fd; + p->setnonblock_op = pcap_setnonblock_fd; + p->stats_op = pcap_stats_bpf; + p->close_op = pcap_close_bpf; return (p); bad: (void)close(fd); +#ifdef BIOCGDLTLIST if (bdl.bfl_list != NULL) free(bdl.bfl_list); +#endif free(p); return (NULL); } int -pcap_setfilter(pcap_t *p, struct bpf_program *fp) +pcap_platform_finddevs(pcap_if_t **alldevsp, char *errbuf) +{ +#ifdef HAVE_DAG_API + if (dag_platform_finddevs(alldevsp, errbuf) < 0) + return (-1); +#endif /* HAVE_DAG_API */ + + return (0); +} + +static int +pcap_setfilter_bpf(pcap_t *p, struct bpf_program *fp) { /* * It looks that BPF code generated by gen_protochain() is not @@ -458,37 +870,41 @@ pcap_setfilter(pcap_t *p, struct bpf_program *fp) * Take a safer side for now. */ if (no_optimize) { + /* + * XXX - what if we already have a filter in the kernel? + */ if (install_bpf_program(p, fp) < 0) return (-1); - } else if (p->sf.rfile != NULL) { - if (install_bpf_program(p, fp) < 0) - return (-1); - } else if (ioctl(p->fd, BIOCSETF, (caddr_t)fp) < 0) { + p->md.use_bpf = 0; /* filtering in userland */ + return (0); + } + + /* + * Free any user-mode filter we might happen to have installed. + */ + pcap_freecode(&p->fcode); + + /* + * Try to install the kernel filter. + */ + if (ioctl(p->fd, BIOCSETF, (caddr_t)fp) < 0) { snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "BIOCSETF: %s", pcap_strerror(errno)); return (-1); } + p->md.use_bpf = 1; /* filtering in the kernel */ return (0); } -int -pcap_set_datalink(pcap_t *p, int dlt) +static int +pcap_set_datalink_bpf(pcap_t *p, int dlt) { - int i; - - for (i = 0; i < p->dlt_count; i++) - if (p->dlt_list[i] == dlt) - break; - if (i >= p->dlt_count) { - (void) snprintf(p->errbuf, sizeof(p->errbuf), - "No such DLT as %d", dlt); - return -1; - } +#ifdef BIOCSDLT if (ioctl(p->fd, BIOCSDLT, &dlt) == -1) { (void) snprintf(p->errbuf, sizeof(p->errbuf), "Cannot set DLT %d: %s", dlt, strerror(errno)); - return -1; + return (-1); } - p->linktype = dlt; - return 0; +#endif + return (0); } -- cgit v1.1