diff options
Diffstat (limited to 'pcap-linux.c')
| -rw-r--r-- | pcap-linux.c | 136 |
1 files changed, 72 insertions, 64 deletions
diff --git a/pcap-linux.c b/pcap-linux.c index b72fdbc1..743e17a3 100644 --- a/pcap-linux.c +++ b/pcap-linux.c @@ -224,7 +224,7 @@ static int is_wifi(const char *); static void map_arphrd_to_dlt(pcap_t *, int, const char *, int); static int pcap_activate_linux(pcap_t *); static int setup_socket(pcap_t *, int); -static int setup_mmapped(pcap_t *, int *); +static int setup_mmapped(pcap_t *); static int pcap_can_set_rfmon_linux(pcap_t *); static int pcap_inject_linux(pcap_t *, const void *, int); static int pcap_stats_linux(pcap_t *, struct pcap_stat *); @@ -245,7 +245,7 @@ union thdr { #define RING_GET_CURRENT_FRAME(h) RING_GET_FRAME_AT(h, h->offset) static void destroy_ring(pcap_t *handle); -static int create_ring(pcap_t *handle, int *status); +static int create_ring(pcap_t *handle); static int prepare_tpacket_socket(pcap_t *handle); static int pcap_read_linux_mmap_v2(pcap_t *, int, pcap_handler , u_char *); #ifdef HAVE_TPACKET3 @@ -996,13 +996,17 @@ pcap_activate_linux(pcap_t *handle) const char *device; int is_any_device; struct ifreq ifr; - int status = 0; - int status2 = 0; + int status; int ret; device = handle->opt.device; /* + * Start out assuming no warnings. + */ + status = 0; + + /* * Make sure the name we were handed will fit into the ioctls we * might perform on the device; if not, return a "No such device" * indication, as the Linux kernel shouldn't support creating @@ -1084,22 +1088,38 @@ pcap_activate_linux(pcap_t *handle) status = ret; goto fail; } + if (ret > 0) { + /* + * We got a warning; return that, as handle->errbuf + * might have been overwritten by this warning. + */ + status = ret; + } + /* - * Success. + * Success (possibly with a warning). * Try to set up memory-mapped access. */ - ret = setup_mmapped(handle, &status); - if (ret == -1) { + ret = setup_mmapped(handle); + if (ret < 0) { /* * We failed to set up to use it, or the * kernel supports it, but we failed to - * enable it. status has been set to the + * enable it. The return value is the * error status to return and, if it's * PCAP_ERROR, handle->errbuf contains * the error message. */ + status = ret; goto fail; } + if (ret > 0) { + /* + * We got a warning; return that, as handle->errbuf + * might have been overwritten by this warning. + */ + status = ret; + } /* * We succeeded. status has been set to the status to return, @@ -1109,9 +1129,9 @@ pcap_activate_linux(pcap_t *handle) * Now that we have activated the mmap ring, we can * set the correct protocol. */ - if ((status2 = iface_bind(handle->fd, handlep->ifindex, + if ((ret = iface_bind(handle->fd, handlep->ifindex, handle->errbuf, pcap_protocol(handle))) != 0) { - status = status2; + status = ret; goto fail; } @@ -2283,7 +2303,8 @@ set_dlt_list_cooked(pcap_t *handle) /* * Try to set up a PF_PACKET socket. - * Returns 0 on success and a PCAP_ERROR_ value on failure. + * Returns 0 or a PCAP_WARNING_ value on success and a PCAP_ERROR_ value + * on failure. */ static int setup_socket(pcap_t *handle, int is_any_device) @@ -2636,17 +2657,18 @@ setup_socket(pcap_t *handle, int is_any_device) /* * Attempt to setup memory-mapped access. * - * On success, returns 1, and sets *status to 0 if there are no warnings - * or to a PCAP_WARNING_ code if there is a warning. + * On success, returns 0 if there are no warnings or a PCAP_WARNING_ code + * if there is a warning. * - * On error, returns -1, and sets *status to the appropriate error code; - * if that is PCAP_ERROR, sets handle->errbuf to the appropriate message. + * On error, returns the appropriate error code; if that is PCAP_ERROR, + * sets handle->errbuf to the appropriate message. */ static int -setup_mmapped(pcap_t *handle, int *status) +setup_mmapped(pcap_t *handle) { struct pcap_linux *handlep = handle->priv; - int ret, flags = MAP_ANONYMOUS | MAP_PRIVATE; + int flags = MAP_ANONYMOUS | MAP_PRIVATE; + int status; /* * Attempt to allocate a buffer to hold the contents of one @@ -2659,34 +2681,32 @@ setup_mmapped(pcap_t *handle, int *status) if (handlep->oneshot_buffer == MAP_FAILED) { pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, errno, "can't allocate oneshot buffer"); - *status = PCAP_ERROR; - return -1; + return PCAP_ERROR; } if (handle->opt.buffer_size == 0) { /* by default request 2M for the ring buffer */ handle->opt.buffer_size = 2*1024*1024; } - ret = prepare_tpacket_socket(handle); - if (ret == -1) { + status = prepare_tpacket_socket(handle); + if (status == -1) { munmap(handlep->oneshot_buffer, handle->snapshot); handlep->oneshot_buffer = NULL; - *status = PCAP_ERROR; - return ret; + return PCAP_ERROR; } - ret = create_ring(handle, status); - if (ret == -1) { + status = create_ring(handle); + if (status < 0) { /* * Error attempting to enable memory-mapped capture; - * fail. create_ring() has set *status. + * fail. The return value is the status to return. */ munmap(handlep->oneshot_buffer, handle->snapshot); handlep->oneshot_buffer = NULL; - return -1; + return status; } /* - * Success. *status has been set either to 0 if there are no + * Success. status has been set either to 0 if there are no * warnings or to a PCAP_WARNING_ value if there is a warning. * * handle->offset is used to get the current position into the rx ring. @@ -2698,7 +2718,7 @@ setup_mmapped(pcap_t *handle, int *status) */ set_poll_timeout(handlep); - return 1; + return status; } /* @@ -2847,14 +2867,14 @@ prepare_tpacket_socket(pcap_t *handle) /* * Attempt to set up memory-mapped access. * - * On success, returns 1, and sets *status to 0 if there are no warnings - * or to a PCAP_WARNING_ code if there is a warning. + * On success, returns 0 if there are no warnings or to a PCAP_WARNING_ code + * if there is a warning. * - * On error, returns -1, and sets *status to the appropriate error code; - * if that is PCAP_ERROR, sets handle->errbuf to the appropriate message. + * On error, returns the appropriate error code; if that is PCAP_ERROR, + * sets handle->errbuf to the appropriate message. */ static int -create_ring(pcap_t *handle, int *status) +create_ring(pcap_t *handle) { struct pcap_linux *handlep = handle->priv; unsigned i, j, frames_per_block; @@ -2872,11 +2892,12 @@ create_ring(pcap_t *handle, int *status) socklen_t len; unsigned int sk_type, tp_reserve, maclen, tp_hdrlen, netoff, macoff; unsigned int frame_size; + int status; /* - * Start out assuming no warnings or errors. + * Start out assuming no warnings. */ - *status = 0; + status = 0; /* * Reserve space for VLAN tag reconstruction. @@ -2911,8 +2932,7 @@ create_ring(pcap_t *handle, int *status) pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, errno, "setsockopt (PACKET_RESERVE)"); - *status = PCAP_ERROR; - return -1; + return PCAP_ERROR; } switch (handlep->tp_version) { @@ -2957,15 +2977,11 @@ create_ring(pcap_t *handle, int *status) mtu = iface_get_mtu(handle->fd, handle->opt.device, handle->errbuf); - if (mtu == -1) { - *status = PCAP_ERROR; - return -1; - } + if (mtu == -1) + return PCAP_ERROR; offload = iface_get_offload(handle); - if (offload == -1) { - *status = PCAP_ERROR; - return -1; - } + if (offload == -1) + return PCAP_ERROR; if (offload) max_frame_len = MAX(mtu, 65535); else @@ -2984,8 +3000,7 @@ create_ring(pcap_t *handle, int *status) &len) < 0) { pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, errno, "getsockopt (SO_TYPE)"); - *status = PCAP_ERROR; - return -1; + return PCAP_ERROR; } maclen = (sk_type == SOCK_DGRAM) ? 0 : MAX_LINKHEADER_SIZE; /* XXX: in the kernel maclen is calculated from @@ -3050,8 +3065,7 @@ create_ring(pcap_t *handle, int *status) snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Internal error: unknown TPACKET_ value %u", handlep->tp_version); - *status = PCAP_ERROR; - return -1; + return PCAP_ERROR; } /* compute the minimum block size that will handle this frame. @@ -3117,10 +3131,9 @@ create_ring(pcap_t *handle, int *status) * and, if they can't, shouldn't * try requesting hardware time stamps. */ - *status = PCAP_ERROR_PERM_DENIED; snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Attempt to set hardware timestamp failed - CAP_NET_ADMIN may be required"); - return -1; + return PCAP_ERROR_PERM_DENIED; case EOPNOTSUPP: case ERANGE: @@ -3138,15 +3151,14 @@ create_ring(pcap_t *handle, int *status) * We'll just fall back on the standard * host time stamps. */ - *status = PCAP_WARNING_TSTAMP_TYPE_NOTSUP; + status = PCAP_WARNING_TSTAMP_TYPE_NOTSUP; break; default: pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, errno, "SIOCSHWTSTAMP failed"); - *status = PCAP_ERROR; - return -1; + return PCAP_ERROR; } } else { /* @@ -3173,8 +3185,7 @@ create_ring(pcap_t *handle, int *status) pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, errno, "can't set PACKET_TIMESTAMP"); - *status = PCAP_ERROR; - return -1; + return PCAP_ERROR; } } } @@ -3235,8 +3246,7 @@ retry: } pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, errno, "can't create rx ring on packet socket"); - *status = PCAP_ERROR; - return -1; + return PCAP_ERROR; } /* memory map the rx ring */ @@ -3251,8 +3261,7 @@ retry: /* clear the allocated ring on error*/ destroy_ring(handle); - *status = PCAP_ERROR; - return -1; + return PCAP_ERROR; } /* allocate a ring for each frame header pointer*/ @@ -3263,8 +3272,7 @@ retry: errno, "can't allocate ring of frame headers"); destroy_ring(handle); - *status = PCAP_ERROR; - return -1; + return PCAP_ERROR; } /* fill the header ring with proper frame ptr*/ @@ -3279,7 +3287,7 @@ retry: handle->bufsize = req.tp_frame_size; handle->offset = 0; - return 1; + return status; } /* free all ring related resources*/ |