diff options
Diffstat (limited to 'sys/net/bpf.h')
| -rw-r--r-- | sys/net/bpf.h | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/sys/net/bpf.h b/sys/net/bpf.h index 91ea0f6..1d6f9db 100644 --- a/sys/net/bpf.h +++ b/sys/net/bpf.h @@ -92,6 +92,27 @@ struct bpf_version { #define BPF_MAJOR_VERSION 1 #define BPF_MINOR_VERSION 1 +/* + * Historically, BPF has supported a single buffering model, first using mbuf + * clusters in kernel, and later using malloc(9) buffers in kernel. We now + * support multiple buffering modes, which may be queried and set using + * BIOCGETBUFMODE and BIOCSETBUFMODE. So as to avoid handling the complexity + * of changing modes while sniffing packets, the mode becomes fixed once an + * interface has been attached to the BPF descriptor. + */ +#define BPF_BUFMODE_BUFFER 1 /* Kernel buffers with read(). */ +#define BPF_BUFMODE_ZBUF 2 /* Zero-copy buffers. */ + +/*- + * Struct used by BIOCSETZBUF, BIOCROTZBUF: describes up to two zero-copy + * buffer as used by BPF. + */ +struct bpf_zbuf { + void *bz_bufa; /* Location of 'a' zero-copy buffer. */ + void *bz_bufb; /* Location of 'b' zero-copy buffer. */ + size_t bz_buflen; /* Size of zero-copy buffers. */ +}; + #define BIOCGBLEN _IOR('B',102, u_int) #define BIOCSBLEN _IOWR('B',102, u_int) #define BIOCSETF _IOW('B',103, struct bpf_program) @@ -116,6 +137,11 @@ struct bpf_version { #define BIOCLOCK _IO('B', 122) #define BIOCSETWF _IOW('B',123, struct bpf_program) #define BIOCFEEDBACK _IOW('B',124, u_int) +#define BIOCGETBUFMODE _IOR('B',125, u_int) +#define BIOCSETBUFMODE _IOW('B',126, u_int) +#define BIOCGETZMAX _IOR('B',127, size_t) +#define BIOCROTZBUF _IOR('B',128, struct bpf_zbuf) +#define BIOCSETZBUF _IOW('B',129, struct bpf_zbuf) /* Obsolete */ #define BIOCGSEESENT BIOCGDIRECTION @@ -149,6 +175,24 @@ struct bpf_hdr { #endif /* + * When using zero-copy BPF buffers, a shared memory header is present + * allowing the kernel BPF implementation and user process to synchronize + * without using system calls. This structure defines that header. When + * accessing these fields, appropriate atomic operation and memory barriers + * are required in order not to see stale or out-of-order data; see bpf(4) + * for reference code to access these fields from userspace. + * + * The layout of this structure is critical, and must not be changed; if must + * fit in a single page on all architectures. + */ +struct bpf_zbuf_header { + volatile u_int bzh_kernel_gen; /* Kernel generation number. */ + volatile u_int bzh_kernel_len; /* Length of data in the buffer. */ + volatile u_int bzh_user_gen; /* User generation number. */ + u_int _bzh_pad[5]; +}; + +/* * Data-link level type codes. */ #define DLT_NULL 0 /* BSD loopback encapsulation */ @@ -761,6 +805,27 @@ struct bpf_dltlist { }; #ifdef _KERNEL +#ifdef MALLOC_DECLARE +MALLOC_DECLARE(M_BPF); +#endif +#ifdef SYSCTL_DECL +SYSCTL_DECL(_net_bpf); +#endif + +/* + * Rotate the packet buffers in descriptor d. Move the store buffer into the + * hold slot, and the free buffer ino the store slot. Zero the length of the + * new store buffer. Descriptor lock should be held. + */ +#define ROTATE_BUFFERS(d) do { \ + (d)->bd_hbuf = (d)->bd_sbuf; \ + (d)->bd_hlen = (d)->bd_slen; \ + (d)->bd_sbuf = (d)->bd_fbuf; \ + (d)->bd_slen = 0; \ + (d)->bd_fbuf = NULL; \ + bpf_bufheld(d); \ +} while (0) + /* * Descriptor associated with each attached hardware interface. */ @@ -773,6 +838,7 @@ struct bpf_if { struct mtx bif_mtx; /* mutex for interface */ }; +void bpf_bufheld(struct bpf_d *d); int bpf_validate(const struct bpf_insn *, int); void bpf_tap(struct bpf_if *, u_char *, u_int); void bpf_mtap(struct bpf_if *, struct mbuf *); |
