X-Git-Url: https://git.tcpdump.org/libpcap/blobdiff_plain/c6e2cb7607c413ab1bdb53ba915dd2bd89e029ef..09b51d326c38ea8e10ce4da09c09d50e08c5aeb8:/pcap-npf.c diff --git a/pcap-npf.c b/pcap-npf.c index e385b2ac..99b5981e 100644 --- a/pcap-npf.c +++ b/pcap-npf.c @@ -36,6 +36,7 @@ #endif #include +#include /* for INT_MAX */ #define PCAP_DONT_INCLUDE_PCAP_BPF_H #include #include @@ -445,6 +446,31 @@ pcap_setuserbuffer_npf(pcap_t *p, int size) return (0); } +#ifdef HAVE_NPCAP_PACKET_API +/* + * Kernel dump mode isn't supported in Npcap; calls to PacketSetDumpName(), + * PacketSetDumpLimits(), and PacketIsDumpEnded() will get compile-time + * deprecation warnings. + * + * Avoid calling them; just return errors indicating that kernel dump + * mode isn't supported in Npcap. + */ +static int +pcap_live_dump_npf(pcap_t *p, char *filename _U_, int maxsize _U_, + int maxpacks _U_) +{ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "Npcap doesn't support kernel dump mode"); + return (-1); +} +static int +pcap_live_dump_ended_npf(pcap_t *p, int sync) +{ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "Npcap doesn't support kernel dump mode"); + return (-1); +} +#else /* HAVE_NPCAP_PACKET_API */ static int pcap_live_dump_npf(pcap_t *p, char *filename, int maxsize, int maxpacks) { @@ -485,6 +511,7 @@ pcap_live_dump_ended_npf(pcap_t *p, int sync) return (PacketIsDumpEnded(pw->adapter, (BOOLEAN)sync)); } +#endif /* HAVE_NPCAP_PACKET_API */ #ifdef HAVE_AIRPCAP_API static PAirpcapHandle @@ -607,6 +634,9 @@ pcap_read_npf(pcap_t *p, int cnt, pcap_handler callback, u_char *user) /* * Loop through each packet. + * + * This assumes that a single buffer of packets will have + * <= INT_MAX packets, so the packet count doesn't overflow. */ #define bhp ((struct bpf_hdr *)bp) n = 0; @@ -766,6 +796,21 @@ pcap_read_win32_dag(pcap_t *p, int cnt, pcap_handler callback, u_char *user) endofbuf = (char*)header + cc; + /* + * This can conceivably process more than INT_MAX packets, + * which would overflow the packet count, causing it either + * to look like a negative number, and thus cause us to + * return a value that looks like an error, or overflow + * back into positive territory, and thus cause us to + * return a too-low count. + * + * Therefore, if the packet count is unlimited, we clip + * it at INT_MAX; this routine is not expected to + * process packets indefinitely, so that's not an issue. + */ + if (PACKET_COUNT_IS_UNLIMITED(cnt)) + cnt = INT_MAX; + /* * Cycle through the packets */ @@ -856,7 +901,7 @@ pcap_read_win32_dag(pcap_t *p, int cnt, pcap_handler callback, u_char *user) } } - /* No underlaying filtering system. We need to filter on our own */ + /* No underlying filtering system. We need to filter on our own */ if (p->fcode.bf_insns) { if (pcap_filter(p->fcode.bf_insns, dp, packet_len, caplen) == 0) @@ -867,7 +912,7 @@ pcap_read_win32_dag(pcap_t *p, int cnt, pcap_handler callback, u_char *user) } } - /* Fill the header for the user suppplied callback function */ + /* Fill the header for the user supplied callback function */ pcap_header.caplen = caplen; pcap_header.len = packet_len; @@ -940,8 +985,6 @@ pcap_breakloop_npf(pcap_t *p) } /* - * Vendor-specific error codes. - * * These are NTSTATUS values: * * https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-erref/87fba13e-bf06-450e-83b1-9241dc81e781 @@ -950,15 +993,28 @@ pcap_breakloop_npf(pcap_t *p) * mapped to Windows error values in userland; they're returned by * GetLastError(). * - * Attempting to set non-promiscuous mode on a Microsoft Surface Pro's - * Mobile Broadband Adapter returns an error; that error can safely be - * ignored, as it's always in non-promiscuous mode. + * Note that "driver" here includes the Npcap NPF driver, as various + * versions would take NT status values and set the "Customer" bit + * before returning the status code. The commit message for the + * change that started doing that is + * + * Returned a customer-defined NTSTATUS in OID requests to avoid + * NTSTATUS-to-Win32 Error code translation. + * + * but I don't know why the goal was to avoid that translation. + * + * Attempting to set the hardware filter on a Microsoft Surface Pro's + * Mobile Broadband Adapter returns an error that appears to be + * NDIS_STATUS_NOT_SUPPORTED ORed with the "Customer" bit, so it's + * probably indicating that it doesn't support that. * * It is likely that there are other devices which throw spurious errors, * at which point this will need refactoring to efficiently check against - * a list, but for now we can just check this one value. + * a list, but for now we can just check this one value. Perhaps the + * right way to do this is compare against various NDIS errors with + * the "customer" bit ORed in. */ -#define NPF_SURFACE_MOBILE_NONPROMISC 0xe00000bb +#define NT_STATUS_CUSTOMER_DEFINED 0x20000000 static int pcap_activate_npf(pcap_t *p) @@ -1017,14 +1073,22 @@ pcap_activate_npf(pcap_t *p) case ERROR_BAD_UNIT: /* * There's no such device. + * There's nothing to add, so clear the error + * message. */ + p->errbuf[0] = '\0'; return (PCAP_ERROR_NO_SUCH_DEVICE); case ERROR_ACCESS_DENIED: /* * There is, but we don't have permission to * use it. + * + * XXX - we currently get ERROR_BAD_UNIT if the + * user says "no" to the UAC prompt. */ + snprintf(p->errbuf, PCAP_ERRBUF_SIZE, + "The helper program for \"Admin-only Mode\" must be allowed to make changes to your device"); return (PCAP_ERROR_PERM_DENIED); default: @@ -1240,7 +1304,13 @@ pcap_activate_npf(pcap_t *p) /* * Suppress spurious error generated by non-compiant - * MS Surface mobile adapters. + * MS Surface mobile adapters that appear to + * return NDIS_STATUS_NOT_SUPPORTED for attempts + * to set the hardware filter. + * + * It appears to be reporting NDIS_STATUS_NOT_SUPPORTED, + * but with the NT status value "Customer" bit set; + * the Npcap NPF driver sets that bit in some cases. * * If we knew that this meant "promiscuous mode * isn't supported", we could add a "promiscuous @@ -1262,8 +1332,17 @@ pcap_activate_npf(pcap_t *p) * and rejecting it with an error could disrupt * attempts to capture, as many programs (tcpdump, * *shark) default to promiscuous mode. + * + * Alternatively, we could return the "promiscuous + * mode not supported" *warning* value, so that + * correct code will either ignore it or report + * it and continue capturing. (This may require + * a pcap_init() flag to request that return + * value, so that old incorrect programs that + * assume a non-zero return from pcap_activate() + * is an error don't break.) */ - if (errcode != NPF_SURFACE_MOBILE_NONPROMISC) + if (errcode != (NDIS_STATUS_NOT_SUPPORTED|NT_STATUS_CUSTOMER_DEFINED)) { pcap_fmt_errmsg_for_win32_err(p->errbuf, PCAP_ERRBUF_SIZE, errcode, @@ -1294,7 +1373,7 @@ pcap_activate_npf(pcap_t *p) * Suppress spurious error generated by non-compiant * MS Surface mobile adapters. */ - if (errcode != NPF_SURFACE_MOBILE_NONPROMISC) + if (errcode != (NDIS_STATUS_NOT_SUPPORTED|NT_STATUS_CUSTOMER_DEFINED)) { pcap_fmt_errmsg_for_win32_err(p->errbuf, PCAP_ERRBUF_SIZE, errcode, @@ -1511,30 +1590,22 @@ pcap_can_set_rfmon_npf(pcap_t *p) return (PacketIsMonitorModeSupported(p->opt.device) == 1); } -pcap_t * -pcap_create_interface(const char *device _U_, char *ebuf) -{ - pcap_t *p; +/* + * Get a list of time stamp types. + */ #ifdef HAVE_PACKET_GET_TIMESTAMP_MODES +static int +get_ts_types(const char *device, pcap_t *p, char *ebuf) +{ char *device_copy = NULL; ADAPTER *adapter = NULL; ULONG num_ts_modes; BOOL ret; DWORD error = ERROR_SUCCESS; ULONG *modes = NULL; -#endif - - p = PCAP_CREATE_COMMON(ebuf, struct pcap_win); - if (p == NULL) - return (NULL); - - p->activate_op = pcap_activate_npf; - p->can_set_rfmon_op = pcap_can_set_rfmon_npf; + int status = 0; -#ifdef HAVE_PACKET_GET_TIMESTAMP_MODES do { - /* Must fill out ebuf to signal an error at end of do/while */ - ebuf[0] = '\0'; /* * First, find out how many time stamp modes we have. * To do that, we have to open the adapter. @@ -1546,6 +1617,7 @@ pcap_create_interface(const char *device _U_, char *ebuf) device_copy = strdup(device); if (device_copy == NULL) { pcap_fmt_errmsg_for_errno(ebuf, PCAP_ERRBUF_SIZE, errno, "malloc"); + status = -1; break; } @@ -1553,11 +1625,49 @@ pcap_create_interface(const char *device _U_, char *ebuf) if (adapter == NULL) { error = GetLastError(); - /* If we can't open the device now, we won't be able to later, either. */ - pcap_fmt_errmsg_for_win32_err(ebuf, PCAP_ERRBUF_SIZE, - error, "Error opening adapter"); + /* + * If we can't open the device now, we won't be + * able to later, either. + * + * If the error is something that indicates + * that the device doesn't exist, or that they + * don't have permission to open the device - or + * perhaps that they don't have permission to get + * a list of devices, if PacketOpenAdapter() does + * that - the user will find that out when they try + * to activate the device; just return an empty + * list of time stamp types. + * + * Treating either of those as errors will, for + * example, cause "tcpdump -i " to fail, + * because it first tries to pass the interface + * name to pcap_create() and pcap_activate(), + * in order to handle OSes where interfaces can + * have names that are just numbers (stand up + * and say hello, Linux!), and, if pcap_activate() + * fails with a "no such device" error, checks + * whether the interface name is a valid number + * and, if so, tries to use it as an index in + * the list of interfaces. + * + * That means pcap_create() must succeed even + * for interfaces that don't exist, with the + * failure occurring at pcap_activate() time. + */ + if (error == ERROR_BAD_UNIT || + error == ERROR_ACCESS_DENIED) { + p->tstamp_type_count = 0; + p->tstamp_type_list = NULL; + status = 0; + } else { + pcap_fmt_errmsg_for_win32_err(ebuf, + PCAP_ERRBUF_SIZE, error, + "Error opening adapter"); + status = -1; + } break; } + /* * Get the total number of time stamp modes. * @@ -1607,7 +1717,8 @@ pcap_create_interface(const char *device _U_, char *ebuf) * out all older drivers. */ snprintf(ebuf, PCAP_ERRBUF_SIZE, - "PacketGetTimestampModes() failed with ERROR_INVALID_FUNCTION; try uninstalling Npcap, and WinPcap if installed, and re-installing it from npcap.org"); + "PacketGetTimestampModes() failed with ERROR_INVALID_FUNCTION; try uninstalling Npcap, and WinPcap if installed, and re-installing it from npcap.com"); + status = -1; break; } @@ -1617,6 +1728,7 @@ pcap_create_interface(const char *device _U_, char *ebuf) pcap_fmt_errmsg_for_win32_err(ebuf, PCAP_ERRBUF_SIZE, error, "Error calling PacketGetTimestampModes"); + status = -1; break; } } @@ -1633,6 +1745,7 @@ pcap_create_interface(const char *device _U_, char *ebuf) if (num_ts_modes == 0) { snprintf(ebuf, PCAP_ERRBUF_SIZE, "PacketGetTimestampModes() reports 0 modes supported."); + status = -1; break; } @@ -1647,6 +1760,7 @@ pcap_create_interface(const char *device _U_, char *ebuf) if (modes == NULL) { /* Out of memory. */ pcap_fmt_errmsg_for_errno(ebuf, PCAP_ERRBUF_SIZE, errno, "malloc"); + status = -1; break; } modes[0] = 1 + num_ts_modes; @@ -1654,12 +1768,14 @@ pcap_create_interface(const char *device _U_, char *ebuf) pcap_fmt_errmsg_for_win32_err(ebuf, PCAP_ERRBUF_SIZE, GetLastError(), "Error calling PacketGetTimestampModes"); + status = -1; break; } if (modes[0] != num_ts_modes) { snprintf(ebuf, PCAP_ERRBUF_SIZE, "First PacketGetTimestampModes() call gives %lu modes, second call gives %lu modes", num_ts_modes, modes[0]); + status = -1; break; } @@ -1671,6 +1787,7 @@ pcap_create_interface(const char *device _U_, char *ebuf) p->tstamp_type_list = malloc((1 + num_ts_modes) * sizeof(u_int)); if (p->tstamp_type_list == NULL) { pcap_fmt_errmsg_for_errno(ebuf, PCAP_ERRBUF_SIZE, errno, "malloc"); + status = -1; break; } u_int num_ts_types = 0; @@ -1733,18 +1850,35 @@ pcap_create_interface(const char *device _U_, char *ebuf) PacketCloseAdapter(adapter); } - /* Error condition signaled by ebuf containing an error message */ - if (ebuf[0] != '\0') { - /* Undo any changes. Must not use pcap_close() - * since none of the ops have been set. */ - if (p->tstamp_type_list != NULL) { - free(p->tstamp_type_list); - } - free(p); - p = NULL; - } + return status; +} +#else /* HAVE_PACKET_GET_TIMESTAMP_MODES */ +static int +get_ts_types(const char *device _U_, pcap_t *p _U_, char *ebuf _U_) +{ + /* + * Nothing to fetch, so it always "succeeds". + */ + return 0; +} #endif /* HAVE_PACKET_GET_TIMESTAMP_MODES */ +pcap_t * +pcap_create_interface(const char *device _U_, char *ebuf) +{ + pcap_t *p; + + p = PCAP_CREATE_COMMON(ebuf, struct pcap_win); + if (p == NULL) + return (NULL); + + p->activate_op = pcap_activate_npf; + p->can_set_rfmon_op = pcap_can_set_rfmon_npf; + + if (get_ts_types(device, p, ebuf) == -1) { + pcap_close(p); + return (NULL); + } return (p); } @@ -1951,8 +2085,8 @@ get_if_flags(const char *name, bpf_u_int32 *flags, char *errbuf) #ifdef OID_GEN_PHYSICAL_MEDIUM_EX OID_GEN_PHYSICAL_MEDIUM_EX, #endif - OID_GEN_PHYSICAL_MEDIUM - }; + OID_GEN_PHYSICAL_MEDIUM + }; #define N_GEN_PHYSICAL_MEDIUM_OIDS (sizeof gen_physical_medium_oids / sizeof gen_physical_medium_oids[0]) size_t i; #endif /* OID_GEN_PHYSICAL_MEDIUM */ @@ -2005,7 +2139,7 @@ get_if_flags(const char *name, bpf_u_int32 *flags, char *errbuf) *flags |= PCAP_IF_WIRELESS; /* - * A "network assosiation state" makes no sense for airpcap. + * A "network association state" makes no sense for airpcap. */ *flags |= PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE; PacketCloseAdapter(adapter); @@ -2264,7 +2398,7 @@ pcap_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf) desc++; /* - * Found it - "desc" points to the first of the two + * Found it - "desc" points to the first of the two * nulls at the end of the list of names, so the * first byte of the list of descriptions is two bytes * after it.