diff options
Diffstat (limited to 'pcap-linux.c')
| -rw-r--r-- | pcap-linux.c | 98 |
1 files changed, 97 insertions, 1 deletions
diff --git a/pcap-linux.c b/pcap-linux.c index 19bd8659..f7c456ff 100644 --- a/pcap-linux.c +++ b/pcap-linux.c @@ -332,7 +332,6 @@ struct pcap_linux { #ifdef HAVE_SYS_EVENTFD_H int poll_breakloop_fd; /* fd to an eventfd to break from blocking operations */ #endif - }; /* @@ -506,6 +505,9 @@ static struct sock_fprog total_fcode = { 1, &total_insn }; #endif /* SO_ATTACH_FILTER */ +static int iface_dsa_get_proto_info(const char *device, pcap_t *handle, + char *ebuf); + pcap_t * pcap_create_interface(const char *device, char *ebuf) { @@ -3298,6 +3300,28 @@ static void map_arphrd_to_dlt(pcap_t *handle, int sock_fd, int arptype, * others? */ if (!is_wifi(sock_fd, device)) { + int ret; + + /* + * This is not a Wi-Fi device but it could be + * a DSA master/management network device. + */ + ret = iface_dsa_get_proto_info(device, handle, + handle->errbuf); + if (ret < 0) + return; + + if (ret == 1) { + /* + * This is a DSA master/management network + * device linktype is already set by + * iface_dsa_get_proto_info() set an + * appropriate offset here. + */ + handle->offset = 2; + break; + } + /* * It's not a Wi-Fi device; offer DOCSIS. */ @@ -6900,6 +6924,78 @@ iface_get_offload(pcap_t *handle _U_) #endif /* HAVE_PF_PACKET_SOCKETS */ +static struct dsa_proto { + const char *name; + bpf_u_int32 linktype; +} dsa_protos[] = { + /* + * None is special and indicates that the interface does not have + * any tagging protocol configured, and is therefore a standard + * Ethernet interface. + */ + { "none", DLT_EN10MB }, + { "brcm", DLT_DSA_TAG_BRCM }, + { "brcm-prepend", DLT_DSA_TAG_BRCM_PREPEND }, +}; + +static int iface_dsa_get_proto_info(const char *device, pcap_t *handle, + char *ebuf) +{ + char *pathstr; + unsigned int i; + char buf[256]; + ssize_t r; + int fd; + + fd = asprintf(&pathstr, "/sys/class/net/%s/dsa/tagging", device); + if (fd < 0) { + pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, + fd, "asprintf"); + return PCAP_ERROR; + } + + fd = open(pathstr, O_RDONLY); + free(pathstr); + /* + * This is not fatal, kernel >= 4.20 *might* expose this attribute + */ + if (fd < 0) + return 0; + + r = read(fd, buf, sizeof(buf) - 1); + close(fd); + if (r <= 0) { + pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, + r, "read"); + return PCAP_ERROR; + } + + /* + * Buffer should be LF terminated. + */ + if (buf[r - 1] == '\n') + r--; + buf[r] = '\0'; + + for (i = 0; i < sizeof(dsa_protos) / sizeof(dsa_protos[0]); i++) { + if (strlen(dsa_protos[i].name) == r && + !strcmp(buf, dsa_protos[i].name)) { + handle->linktype = dsa_protos[i].linktype; + switch (dsa_protos[i].linktype) { + case DLT_EN10MB: + return 0; + default: + return 1; + } + } + } + + pcap_snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, + "unsupported DSA tag: %s", buf); + + return PCAP_ERROR; +} + /* ===== Functions to interface to the older kernels ================== */ /* |