diff options
Diffstat (limited to 'pcap-bpf.c')
| -rw-r--r-- | pcap-bpf.c | 37 |
1 files changed, 27 insertions, 10 deletions
@@ -478,7 +478,7 @@ bpf_open(char *errbuf) { int fd = -1; static const char cloning_device[] = "/dev/bpf"; - int n = 0; + u_int n = 0; char device[sizeof "/dev/bpf0000000000"]; static int no_cloning_bpf = 0; @@ -503,12 +503,17 @@ bpf_open(char *errbuf) ((errno != EACCES && errno != ENOENT) || (fd = open(cloning_device, O_RDONLY)) == -1)) { if (errno != ENOENT) { - if (errno == EACCES) + if (errno == EACCES) { fd = PCAP_ERROR_PERM_DENIED; - else + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "Attempt to open %s failed - root privileges may be required", + cloning_device); + } else { fd = PCAP_ERROR; - pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, - errno, "(cannot open device) %s", cloning_device); + pcap_fmt_errmsg_for_errno(errbuf, + PCAP_ERRBUF_SIZE, errno, + "(cannot open device) %s", cloning_device); + } return (fd); } no_cloning_bpf = 1; @@ -521,7 +526,7 @@ bpf_open(char *errbuf) * that isn't in use. */ do { - (void)snprintf(device, sizeof(device), "/dev/bpf%d", n++); + (void)snprintf(device, sizeof(device), "/dev/bpf%u", n++); /* * Initially try a read/write open (to allow the inject * method to work). If that fails due to permission @@ -577,8 +582,9 @@ bpf_open(char *errbuf) * if any. */ fd = PCAP_ERROR_PERM_DENIED; - pcap_fmt_errmsg_for_errno(errbuf, PCAP_ERRBUF_SIZE, - errno, "(cannot open BPF device) %s", device); + snprintf(errbuf, PCAP_ERRBUF_SIZE, + "Attempt to open %s failed - root privileges may be required", + device); break; default: @@ -655,7 +661,11 @@ bpf_bind(int fd, const char *name, char *errbuf) case ENXIO: /* * There's no such device. + * + * There's nothing more to say, so clear out the + * error message. */ + errbuf[0] = '\0'; return (PCAP_ERROR_NO_SUCH_DEVICE); case ENETDOWN: @@ -1177,6 +1187,9 @@ pcap_read_bpf(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. */ #ifdef BIOCSTSTAMP #define bhp ((struct bpf_xhdr *)bp) @@ -2191,7 +2204,7 @@ pcap_activate_bpf(pcap_t *p) * * Otherwise, fail. */ - if (errno != BPF_BIND_BUFFER_TOO_BIG) { + if (status != BPF_BIND_BUFFER_TOO_BIG) { /* * Special checks on macOS to deal * with the way monitor mode was @@ -2968,7 +2981,7 @@ get_if_flags(const char *name, bpf_u_int32 *flags, char *errbuf) } #else static int -get_if_flags(const char *name _U_, bpf_u_int32 *flags _U_, char *errbuf _U_) +get_if_flags(const char *name _U_, bpf_u_int32 *flags, char *errbuf _U_) { /* * Nothing we can do other than mark loopback devices as "the @@ -3043,7 +3056,11 @@ monitor_mode(pcap_t *p, int set) case ENXIO: /* * There's no such device. + * + * There's nothing more to say, so clear the + * error message. */ + p->errbuf[0] = '\0'; close(sock); return (PCAP_ERROR_NO_SUCH_DEVICE); |