diff options
Diffstat (limited to 'tools/net')
| -rw-r--r-- | tools/net/Makefile | 25 | ||||
| -rw-r--r-- | tools/net/bpf_asm.c | 52 | ||||
| -rw-r--r-- | tools/net/bpf_dbg.c | 1395 | ||||
| -rw-r--r-- | tools/net/bpf_exp.l | 144 | ||||
| -rw-r--r-- | tools/net/bpf_exp.y | 771 | ||||
| -rw-r--r-- | tools/net/bpf_jit_disasm.c | 20 | 
6 files changed, 2393 insertions, 14 deletions
diff --git a/tools/net/Makefile b/tools/net/Makefile index b4444d53b73..ee577ea03ba 100644 --- a/tools/net/Makefile +++ b/tools/net/Makefile @@ -1,15 +1,34 @@  prefix = /usr  CC = gcc +LEX = flex +YACC = bison -all : bpf_jit_disasm +%.yacc.c: %.y +	$(YACC) -o $@ -d $< -bpf_jit_disasm : CFLAGS = -Wall -O2 +%.lex.c: %.l +	$(LEX) -o $@ $< + +all : bpf_jit_disasm bpf_dbg bpf_asm + +bpf_jit_disasm : CFLAGS = -Wall -O2 -DPACKAGE='bpf_jit_disasm'  bpf_jit_disasm : LDLIBS = -lopcodes -lbfd -ldl  bpf_jit_disasm : bpf_jit_disasm.o +bpf_dbg : CFLAGS = -Wall -O2 +bpf_dbg : LDLIBS = -lreadline +bpf_dbg : bpf_dbg.o + +bpf_asm : CFLAGS = -Wall -O2 -I. +bpf_asm : LDLIBS = +bpf_asm : bpf_asm.o bpf_exp.yacc.o bpf_exp.lex.o +bpf_exp.lex.o : bpf_exp.yacc.c +  clean : -	rm -rf *.o bpf_jit_disasm +	rm -rf *.o bpf_jit_disasm bpf_dbg bpf_asm bpf_exp.yacc.* bpf_exp.lex.*  install :  	install bpf_jit_disasm $(prefix)/bin/bpf_jit_disasm +	install bpf_dbg $(prefix)/bin/bpf_dbg +	install bpf_asm $(prefix)/bin/bpf_asm diff --git a/tools/net/bpf_asm.c b/tools/net/bpf_asm.c new file mode 100644 index 00000000000..c15aef097b0 --- /dev/null +++ b/tools/net/bpf_asm.c @@ -0,0 +1,52 @@ +/* + * Minimal BPF assembler + * + * Instead of libpcap high-level filter expressions, it can be quite + * useful to define filters in low-level BPF assembler (that is kept + * close to Steven McCanne and Van Jacobson's original BPF paper). + * In particular for BPF JIT implementors, JIT security auditors, or + * just for defining BPF expressions that contain extensions which are + * not supported by compilers. + * + * How to get into it: + * + * 1) read Documentation/networking/filter.txt + * 2) Run `bpf_asm [-c] <filter-prog file>` to translate into binary + *    blob that is loadable with xt_bpf, cls_bpf et al. Note: -c will + *    pretty print a C-like construct. + * + * Copyright 2013 Daniel Borkmann <borkmann@redhat.com> + * Licensed under the GNU General Public License, version 2.0 (GPLv2) + */ + +#include <stdbool.h> +#include <stdio.h> +#include <string.h> + +extern void bpf_asm_compile(FILE *fp, bool cstyle); + +int main(int argc, char **argv) +{ +	FILE *fp = stdin; +	bool cstyle = false; +	int i; + +	for (i = 1; i < argc; i++) { +		if (!strncmp("-c", argv[i], 2)) { +			cstyle = true; +			continue; +		} + +		fp = fopen(argv[i], "r"); +		if (!fp) { +			fp = stdin; +			continue; +		} + +		break; +	} + +	bpf_asm_compile(fp, cstyle); + +	return 0; +} diff --git a/tools/net/bpf_dbg.c b/tools/net/bpf_dbg.c new file mode 100644 index 00000000000..9a287bec695 --- /dev/null +++ b/tools/net/bpf_dbg.c @@ -0,0 +1,1395 @@ +/* + * Minimal BPF debugger + * + * Minimal BPF debugger that mimics the kernel's engine (w/o extensions) + * and allows for single stepping through selected packets from a pcap + * with a provided user filter in order to facilitate verification of a + * BPF program. Besides others, this is useful to verify BPF programs + * before attaching to a live system, and can be used in socket filters, + * cls_bpf, xt_bpf, team driver and e.g. PTP code; in particular when a + * single more complex BPF program is being used. Reasons for a more + * complex BPF program are likely primarily to optimize execution time + * for making a verdict when multiple simple BPF programs are combined + * into one in order to prevent parsing same headers multiple times. + * + * More on how to debug BPF opcodes see Documentation/networking/filter.txt + * which is the main document on BPF. Mini howto for getting started: + * + *  1) `./bpf_dbg` to enter the shell (shell cmds denoted with '>'): + *  2) > load bpf 6,40 0 0 12,21 0 3 20... (output from `bpf_asm` or + *     `tcpdump -iem1 -ddd port 22 | tr '\n' ','` to load as filter) + *  3) > load pcap foo.pcap + *  4) > run <n>/disassemble/dump/quit (self-explanatory) + *  5) > breakpoint 2 (sets bp at loaded BPF insns 2, do `run` then; + *       multiple bps can be set, of course, a call to `breakpoint` + *       w/o args shows currently loaded bps, `breakpoint reset` for + *       resetting all breakpoints) + *  6) > select 3 (`run` etc will start from the 3rd packet in the pcap) + *  7) > step [-<n>, +<n>] (performs single stepping through the BPF) + * + * Copyright 2013 Daniel Borkmann <borkmann@redhat.com> + * Licensed under the GNU General Public License, version 2.0 (GPLv2) + */ + +#include <stdio.h> +#include <unistd.h> +#include <stdlib.h> +#include <ctype.h> +#include <stdbool.h> +#include <stdarg.h> +#include <setjmp.h> +#include <linux/filter.h> +#include <linux/if_packet.h> +#include <readline/readline.h> +#include <readline/history.h> +#include <sys/types.h> +#include <sys/socket.h> +#include <sys/stat.h> +#include <sys/mman.h> +#include <fcntl.h> +#include <errno.h> +#include <signal.h> +#include <arpa/inet.h> +#include <net/ethernet.h> + +#define TCPDUMP_MAGIC	0xa1b2c3d4 + +#define BPF_LDX_B	(BPF_LDX | BPF_B) +#define BPF_LDX_W	(BPF_LDX | BPF_W) +#define BPF_JMP_JA	(BPF_JMP | BPF_JA) +#define BPF_JMP_JEQ	(BPF_JMP | BPF_JEQ) +#define BPF_JMP_JGT	(BPF_JMP | BPF_JGT) +#define BPF_JMP_JGE	(BPF_JMP | BPF_JGE) +#define BPF_JMP_JSET	(BPF_JMP | BPF_JSET) +#define BPF_ALU_ADD	(BPF_ALU | BPF_ADD) +#define BPF_ALU_SUB	(BPF_ALU | BPF_SUB) +#define BPF_ALU_MUL	(BPF_ALU | BPF_MUL) +#define BPF_ALU_DIV	(BPF_ALU | BPF_DIV) +#define BPF_ALU_MOD	(BPF_ALU | BPF_MOD) +#define BPF_ALU_NEG	(BPF_ALU | BPF_NEG) +#define BPF_ALU_AND	(BPF_ALU | BPF_AND) +#define BPF_ALU_OR	(BPF_ALU | BPF_OR) +#define BPF_ALU_XOR	(BPF_ALU | BPF_XOR) +#define BPF_ALU_LSH	(BPF_ALU | BPF_LSH) +#define BPF_ALU_RSH	(BPF_ALU | BPF_RSH) +#define BPF_MISC_TAX	(BPF_MISC | BPF_TAX) +#define BPF_MISC_TXA	(BPF_MISC | BPF_TXA) +#define BPF_LD_B	(BPF_LD | BPF_B) +#define BPF_LD_H	(BPF_LD | BPF_H) +#define BPF_LD_W	(BPF_LD | BPF_W) + +#ifndef array_size +# define array_size(x)	(sizeof(x) / sizeof((x)[0])) +#endif + +#ifndef __check_format_printf +# define __check_format_printf(pos_fmtstr, pos_fmtargs) \ +	__attribute__ ((format (printf, (pos_fmtstr), (pos_fmtargs)))) +#endif + +enum { +	CMD_OK, +	CMD_ERR, +	CMD_EX, +}; + +struct shell_cmd { +	const char *name; +	int (*func)(char *args); +}; + +struct pcap_filehdr { +	uint32_t magic; +	uint16_t version_major; +	uint16_t version_minor; +	int32_t  thiszone; +	uint32_t sigfigs; +	uint32_t snaplen; +	uint32_t linktype; +}; + +struct pcap_timeval { +	int32_t tv_sec; +	int32_t tv_usec; +}; + +struct pcap_pkthdr { +	struct pcap_timeval ts; +	uint32_t caplen; +	uint32_t len; +}; + +struct bpf_regs { +	uint32_t A; +	uint32_t X; +	uint32_t M[BPF_MEMWORDS]; +	uint32_t R; +	bool     Rs; +	uint16_t Pc; +}; + +static struct sock_filter bpf_image[BPF_MAXINSNS + 1]; +static unsigned int bpf_prog_len = 0; + +static int bpf_breakpoints[64]; +static struct bpf_regs bpf_regs[BPF_MAXINSNS + 1]; +static struct bpf_regs bpf_curr; +static unsigned int bpf_regs_len = 0; + +static int pcap_fd = -1; +static unsigned int pcap_packet = 0; +static size_t pcap_map_size = 0; +static char *pcap_ptr_va_start, *pcap_ptr_va_curr; + +static const char * const op_table[] = { +	[BPF_ST]	= "st", +	[BPF_STX]	= "stx", +	[BPF_LD_B]	= "ldb", +	[BPF_LD_H]	= "ldh", +	[BPF_LD_W]	= "ld", +	[BPF_LDX]	= "ldx", +	[BPF_LDX_B]	= "ldxb", +	[BPF_JMP_JA]	= "ja", +	[BPF_JMP_JEQ]	= "jeq", +	[BPF_JMP_JGT]	= "jgt", +	[BPF_JMP_JGE]	= "jge", +	[BPF_JMP_JSET]	= "jset", +	[BPF_ALU_ADD]	= "add", +	[BPF_ALU_SUB]	= "sub", +	[BPF_ALU_MUL]	= "mul", +	[BPF_ALU_DIV]	= "div", +	[BPF_ALU_MOD]	= "mod", +	[BPF_ALU_NEG]	= "neg", +	[BPF_ALU_AND]	= "and", +	[BPF_ALU_OR]	= "or", +	[BPF_ALU_XOR]	= "xor", +	[BPF_ALU_LSH]	= "lsh", +	[BPF_ALU_RSH]	= "rsh", +	[BPF_MISC_TAX]	= "tax", +	[BPF_MISC_TXA]	= "txa", +	[BPF_RET]	= "ret", +}; + +static __check_format_printf(1, 2) int rl_printf(const char *fmt, ...) +{ +	int ret; +	va_list vl; + +	va_start(vl, fmt); +	ret = vfprintf(rl_outstream, fmt, vl); +	va_end(vl); + +	return ret; +} + +static int matches(const char *cmd, const char *pattern) +{ +	int len = strlen(cmd); + +	if (len > strlen(pattern)) +		return -1; + +	return memcmp(pattern, cmd, len); +} + +static void hex_dump(const uint8_t *buf, size_t len) +{ +	int i; + +	rl_printf("%3u: ", 0); +	for (i = 0; i < len; i++) { +		if (i && !(i % 16)) +			rl_printf("\n%3u: ", i); +		rl_printf("%02x ", buf[i]); +	} +	rl_printf("\n"); +} + +static bool bpf_prog_loaded(void) +{ +	if (bpf_prog_len == 0) +		rl_printf("no bpf program loaded!\n"); + +	return bpf_prog_len > 0; +} + +static void bpf_disasm(const struct sock_filter f, unsigned int i) +{ +	const char *op, *fmt; +	int val = f.k; +	char buf[256]; + +	switch (f.code) { +	case BPF_RET | BPF_K: +		op = op_table[BPF_RET]; +		fmt = "#%#x"; +		break; +	case BPF_RET | BPF_A: +		op = op_table[BPF_RET]; +		fmt = "a"; +		break; +	case BPF_RET | BPF_X: +		op = op_table[BPF_RET]; +		fmt = "x"; +		break; +	case BPF_MISC_TAX: +		op = op_table[BPF_MISC_TAX]; +		fmt = ""; +		break; +	case BPF_MISC_TXA: +		op = op_table[BPF_MISC_TXA]; +		fmt = ""; +		break; +	case BPF_ST: +		op = op_table[BPF_ST]; +		fmt = "M[%d]"; +		break; +	case BPF_STX: +		op = op_table[BPF_STX]; +		fmt = "M[%d]"; +		break; +	case BPF_LD_W | BPF_ABS: +		op = op_table[BPF_LD_W]; +		fmt = "[%d]"; +		break; +	case BPF_LD_H | BPF_ABS: +		op = op_table[BPF_LD_H]; +		fmt = "[%d]"; +		break; +	case BPF_LD_B | BPF_ABS: +		op = op_table[BPF_LD_B]; +		fmt = "[%d]"; +		break; +	case BPF_LD_W | BPF_LEN: +		op = op_table[BPF_LD_W]; +		fmt = "#len"; +		break; +	case BPF_LD_W | BPF_IND: +		op = op_table[BPF_LD_W]; +		fmt = "[x+%d]"; +		break; +	case BPF_LD_H | BPF_IND: +		op = op_table[BPF_LD_H]; +		fmt = "[x+%d]"; +		break; +	case BPF_LD_B | BPF_IND: +		op = op_table[BPF_LD_B]; +		fmt = "[x+%d]"; +		break; +	case BPF_LD | BPF_IMM: +		op = op_table[BPF_LD_W]; +		fmt = "#%#x"; +		break; +	case BPF_LDX | BPF_IMM: +		op = op_table[BPF_LDX]; +		fmt = "#%#x"; +		break; +	case BPF_LDX_B | BPF_MSH: +		op = op_table[BPF_LDX_B]; +		fmt = "4*([%d]&0xf)"; +		break; +	case BPF_LD | BPF_MEM: +		op = op_table[BPF_LD_W]; +		fmt = "M[%d]"; +		break; +	case BPF_LDX | BPF_MEM: +		op = op_table[BPF_LDX]; +		fmt = "M[%d]"; +		break; +	case BPF_JMP_JA: +		op = op_table[BPF_JMP_JA]; +		fmt = "%d"; +		val = i + 1 + f.k; +		break; +	case BPF_JMP_JGT | BPF_X: +		op = op_table[BPF_JMP_JGT]; +		fmt = "x"; +		break; +	case BPF_JMP_JGT | BPF_K: +		op = op_table[BPF_JMP_JGT]; +		fmt = "#%#x"; +		break; +	case BPF_JMP_JGE | BPF_X: +		op = op_table[BPF_JMP_JGE]; +		fmt = "x"; +		break; +	case BPF_JMP_JGE | BPF_K: +		op = op_table[BPF_JMP_JGE]; +		fmt = "#%#x"; +		break; +	case BPF_JMP_JEQ | BPF_X: +		op = op_table[BPF_JMP_JEQ]; +		fmt = "x"; +		break; +	case BPF_JMP_JEQ | BPF_K: +		op = op_table[BPF_JMP_JEQ]; +		fmt = "#%#x"; +		break; +	case BPF_JMP_JSET | BPF_X: +		op = op_table[BPF_JMP_JSET]; +		fmt = "x"; +		break; +	case BPF_JMP_JSET | BPF_K: +		op = op_table[BPF_JMP_JSET]; +		fmt = "#%#x"; +		break; +	case BPF_ALU_NEG: +		op = op_table[BPF_ALU_NEG]; +		fmt = ""; +		break; +	case BPF_ALU_LSH | BPF_X: +		op = op_table[BPF_ALU_LSH]; +		fmt = "x"; +		break; +	case BPF_ALU_LSH | BPF_K: +		op = op_table[BPF_ALU_LSH]; +		fmt = "#%d"; +		break; +	case BPF_ALU_RSH | BPF_X: +		op = op_table[BPF_ALU_RSH]; +		fmt = "x"; +		break; +	case BPF_ALU_RSH | BPF_K: +		op = op_table[BPF_ALU_RSH]; +		fmt = "#%d"; +		break; +	case BPF_ALU_ADD | BPF_X: +		op = op_table[BPF_ALU_ADD]; +		fmt = "x"; +		break; +	case BPF_ALU_ADD | BPF_K: +		op = op_table[BPF_ALU_ADD]; +		fmt = "#%d"; +		break; +	case BPF_ALU_SUB | BPF_X: +		op = op_table[BPF_ALU_SUB]; +		fmt = "x"; +		break; +	case BPF_ALU_SUB | BPF_K: +		op = op_table[BPF_ALU_SUB]; +		fmt = "#%d"; +		break; +	case BPF_ALU_MUL | BPF_X: +		op = op_table[BPF_ALU_MUL]; +		fmt = "x"; +		break; +	case BPF_ALU_MUL | BPF_K: +		op = op_table[BPF_ALU_MUL]; +		fmt = "#%d"; +		break; +	case BPF_ALU_DIV | BPF_X: +		op = op_table[BPF_ALU_DIV]; +		fmt = "x"; +		break; +	case BPF_ALU_DIV | BPF_K: +		op = op_table[BPF_ALU_DIV]; +		fmt = "#%d"; +		break; +	case BPF_ALU_MOD | BPF_X: +		op = op_table[BPF_ALU_MOD]; +		fmt = "x"; +		break; +	case BPF_ALU_MOD | BPF_K: +		op = op_table[BPF_ALU_MOD]; +		fmt = "#%d"; +		break; +	case BPF_ALU_AND | BPF_X: +		op = op_table[BPF_ALU_AND]; +		fmt = "x"; +		break; +	case BPF_ALU_AND | BPF_K: +		op = op_table[BPF_ALU_AND]; +		fmt = "#%#x"; +		break; +	case BPF_ALU_OR | BPF_X: +		op = op_table[BPF_ALU_OR]; +		fmt = "x"; +		break; +	case BPF_ALU_OR | BPF_K: +		op = op_table[BPF_ALU_OR]; +		fmt = "#%#x"; +		break; +	case BPF_ALU_XOR | BPF_X: +		op = op_table[BPF_ALU_XOR]; +		fmt = "x"; +		break; +	case BPF_ALU_XOR | BPF_K: +		op = op_table[BPF_ALU_XOR]; +		fmt = "#%#x"; +		break; +	default: +		op = "nosup"; +		fmt = "%#x"; +		val = f.code; +		break; +	} + +	memset(buf, 0, sizeof(buf)); +	snprintf(buf, sizeof(buf), fmt, val); +	buf[sizeof(buf) - 1] = 0; + +	if ((BPF_CLASS(f.code) == BPF_JMP && BPF_OP(f.code) != BPF_JA)) +		rl_printf("l%d:\t%s %s, l%d, l%d\n", i, op, buf, +			  i + 1 + f.jt, i + 1 + f.jf); +	else +		rl_printf("l%d:\t%s %s\n", i, op, buf); +} + +static void bpf_dump_curr(struct bpf_regs *r, struct sock_filter *f) +{ +	int i, m = 0; + +	rl_printf("pc:       [%u]\n", r->Pc); +	rl_printf("code:     [%u] jt[%u] jf[%u] k[%u]\n", +		  f->code, f->jt, f->jf, f->k); +	rl_printf("curr:     "); +	bpf_disasm(*f, r->Pc); + +	if (f->jt || f->jf) { +		rl_printf("jt:       "); +		bpf_disasm(*(f + f->jt + 1), r->Pc + f->jt + 1); +		rl_printf("jf:       "); +		bpf_disasm(*(f + f->jf + 1), r->Pc + f->jf + 1); +	} + +	rl_printf("A:        [%#08x][%u]\n", r->A, r->A); +	rl_printf("X:        [%#08x][%u]\n", r->X, r->X); +	if (r->Rs) +		rl_printf("ret:      [%#08x][%u]!\n", r->R, r->R); + +	for (i = 0; i < BPF_MEMWORDS; i++) { +		if (r->M[i]) { +			m++; +			rl_printf("M[%d]: [%#08x][%u]\n", i, r->M[i], r->M[i]); +		} +	} +	if (m == 0) +		rl_printf("M[0,%d]:  [%#08x][%u]\n", BPF_MEMWORDS - 1, 0, 0); +} + +static void bpf_dump_pkt(uint8_t *pkt, uint32_t pkt_caplen, uint32_t pkt_len) +{ +	if (pkt_caplen != pkt_len) +		rl_printf("cap: %u, len: %u\n", pkt_caplen, pkt_len); +	else +		rl_printf("len: %u\n", pkt_len); + +	hex_dump(pkt, pkt_caplen); +} + +static void bpf_disasm_all(const struct sock_filter *f, unsigned int len) +{ +	unsigned int i; + +	for (i = 0; i < len; i++) +		bpf_disasm(f[i], i); +} + +static void bpf_dump_all(const struct sock_filter *f, unsigned int len) +{ +	unsigned int i; + +	rl_printf("/* { op, jt, jf, k }, */\n"); +	for (i = 0; i < len; i++) +		rl_printf("{ %#04x, %2u, %2u, %#010x },\n", +			  f[i].code, f[i].jt, f[i].jf, f[i].k); +} + +static bool bpf_runnable(struct sock_filter *f, unsigned int len) +{ +	int sock, ret, i; +	struct sock_fprog bpf = { +		.filter = f, +		.len = len, +	}; + +	sock = socket(AF_INET, SOCK_DGRAM, 0); +	if (sock < 0) { +		rl_printf("cannot open socket!\n"); +		return false; +	} +	ret = setsockopt(sock, SOL_SOCKET, SO_ATTACH_FILTER, &bpf, sizeof(bpf)); +	close(sock); +	if (ret < 0) { +		rl_printf("program not allowed to run by kernel!\n"); +		return false; +	} +	for (i = 0; i < len; i++) { +		if (BPF_CLASS(f[i].code) == BPF_LD && +		    f[i].k > SKF_AD_OFF) { +			rl_printf("extensions currently not supported!\n"); +			return false; +		} +	} + +	return true; +} + +static void bpf_reset_breakpoints(void) +{ +	int i; + +	for (i = 0; i < array_size(bpf_breakpoints); i++) +		bpf_breakpoints[i] = -1; +} + +static void bpf_set_breakpoints(unsigned int where) +{ +	int i; +	bool set = false; + +	for (i = 0; i < array_size(bpf_breakpoints); i++) { +		if (bpf_breakpoints[i] == (int) where) { +			rl_printf("breakpoint already set!\n"); +			set = true; +			break; +		} + +		if (bpf_breakpoints[i] == -1 && set == false) { +			bpf_breakpoints[i] = where; +			set = true; +		} +	} + +	if (!set) +		rl_printf("too many breakpoints set, reset first!\n"); +} + +static void bpf_dump_breakpoints(void) +{ +	int i; + +	rl_printf("breakpoints: "); + +	for (i = 0; i < array_size(bpf_breakpoints); i++) { +		if (bpf_breakpoints[i] < 0) +			continue; +		rl_printf("%d ", bpf_breakpoints[i]); +	} + +	rl_printf("\n"); +} + +static void bpf_reset(void) +{ +	bpf_regs_len = 0; + +	memset(bpf_regs, 0, sizeof(bpf_regs)); +	memset(&bpf_curr, 0, sizeof(bpf_curr)); +} + +static void bpf_safe_regs(void) +{ +	memcpy(&bpf_regs[bpf_regs_len++], &bpf_curr, sizeof(bpf_curr)); +} + +static bool bpf_restore_regs(int off) +{ +	unsigned int index = bpf_regs_len - 1 + off; + +	if (index == 0) { +		bpf_reset(); +		return true; +	} else if (index < bpf_regs_len) { +		memcpy(&bpf_curr, &bpf_regs[index], sizeof(bpf_curr)); +		bpf_regs_len = index; +		return true; +	} else { +		rl_printf("reached bottom of register history stack!\n"); +		return false; +	} +} + +static uint32_t extract_u32(uint8_t *pkt, uint32_t off) +{ +	uint32_t r; + +	memcpy(&r, &pkt[off], sizeof(r)); + +	return ntohl(r); +} + +static uint16_t extract_u16(uint8_t *pkt, uint32_t off) +{ +	uint16_t r; + +	memcpy(&r, &pkt[off], sizeof(r)); + +	return ntohs(r); +} + +static uint8_t extract_u8(uint8_t *pkt, uint32_t off) +{ +	return pkt[off]; +} + +static void set_return(struct bpf_regs *r) +{ +	r->R = 0; +	r->Rs = true; +} + +static void bpf_single_step(struct bpf_regs *r, struct sock_filter *f, +			    uint8_t *pkt, uint32_t pkt_caplen, +			    uint32_t pkt_len) +{ +	uint32_t K = f->k; +	int d; + +	switch (f->code) { +	case BPF_RET | BPF_K: +		r->R = K; +		r->Rs = true; +		break; +	case BPF_RET | BPF_A: +		r->R = r->A; +		r->Rs = true; +		break; +	case BPF_RET | BPF_X: +		r->R = r->X; +		r->Rs = true; +		break; +	case BPF_MISC_TAX: +		r->X = r->A; +		break; +	case BPF_MISC_TXA: +		r->A = r->X; +		break; +	case BPF_ST: +		r->M[K] = r->A; +		break; +	case BPF_STX: +		r->M[K] = r->X; +		break; +	case BPF_LD_W | BPF_ABS: +		d = pkt_caplen - K; +		if (d >= sizeof(uint32_t)) +			r->A = extract_u32(pkt, K); +		else +			set_return(r); +		break; +	case BPF_LD_H | BPF_ABS: +		d = pkt_caplen - K; +		if (d >= sizeof(uint16_t)) +			r->A = extract_u16(pkt, K); +		else +			set_return(r); +		break; +	case BPF_LD_B | BPF_ABS: +		d = pkt_caplen - K; +		if (d >= sizeof(uint8_t)) +			r->A = extract_u8(pkt, K); +		else +			set_return(r); +		break; +	case BPF_LD_W | BPF_IND: +		d = pkt_caplen - (r->X + K); +		if (d >= sizeof(uint32_t)) +			r->A = extract_u32(pkt, r->X + K); +		break; +	case BPF_LD_H | BPF_IND: +		d = pkt_caplen - (r->X + K); +		if (d >= sizeof(uint16_t)) +			r->A = extract_u16(pkt, r->X + K); +		else +			set_return(r); +		break; +	case BPF_LD_B | BPF_IND: +		d = pkt_caplen - (r->X + K); +		if (d >= sizeof(uint8_t)) +			r->A = extract_u8(pkt, r->X + K); +		else +			set_return(r); +		break; +	case BPF_LDX_B | BPF_MSH: +		d = pkt_caplen - K; +		if (d >= sizeof(uint8_t)) { +			r->X = extract_u8(pkt, K); +			r->X = (r->X & 0xf) << 2; +		} else +			set_return(r); +		break; +	case BPF_LD_W | BPF_LEN: +		r->A = pkt_len; +		break; +	case BPF_LDX_W | BPF_LEN: +		r->A = pkt_len; +		break; +	case BPF_LD | BPF_IMM: +		r->A = K; +		break; +	case BPF_LDX | BPF_IMM: +		r->X = K; +		break; +	case BPF_LD | BPF_MEM: +		r->A = r->M[K]; +		break; +	case BPF_LDX | BPF_MEM: +		r->X = r->M[K]; +		break; +	case BPF_JMP_JA: +		r->Pc += K; +		break; +	case BPF_JMP_JGT | BPF_X: +		r->Pc += r->A > r->X ? f->jt : f->jf; +		break; +	case BPF_JMP_JGT | BPF_K: +		r->Pc += r->A > K ? f->jt : f->jf; +		break; +	case BPF_JMP_JGE | BPF_X: +		r->Pc += r->A >= r->X ? f->jt : f->jf; +		break; +	case BPF_JMP_JGE | BPF_K: +		r->Pc += r->A >= K ? f->jt : f->jf; +		break; +	case BPF_JMP_JEQ | BPF_X: +		r->Pc += r->A == r->X ? f->jt : f->jf; +		break; +	case BPF_JMP_JEQ | BPF_K: +		r->Pc += r->A == K ? f->jt : f->jf; +		break; +	case BPF_JMP_JSET | BPF_X: +		r->Pc += r->A & r->X ? f->jt : f->jf; +		break; +	case BPF_JMP_JSET | BPF_K: +		r->Pc += r->A & K ? f->jt : f->jf; +		break; +	case BPF_ALU_NEG: +		r->A = -r->A; +		break; +	case BPF_ALU_LSH | BPF_X: +		r->A <<= r->X; +		break; +	case BPF_ALU_LSH | BPF_K: +		r->A <<= K; +		break; +	case BPF_ALU_RSH | BPF_X: +		r->A >>= r->X; +		break; +	case BPF_ALU_RSH | BPF_K: +		r->A >>= K; +		break; +	case BPF_ALU_ADD | BPF_X: +		r->A += r->X; +		break; +	case BPF_ALU_ADD | BPF_K: +		r->A += K; +		break; +	case BPF_ALU_SUB | BPF_X: +		r->A -= r->X; +		break; +	case BPF_ALU_SUB | BPF_K: +		r->A -= K; +		break; +	case BPF_ALU_MUL | BPF_X: +		r->A *= r->X; +		break; +	case BPF_ALU_MUL | BPF_K: +		r->A *= K; +		break; +	case BPF_ALU_DIV | BPF_X: +	case BPF_ALU_MOD | BPF_X: +		if (r->X == 0) { +			set_return(r); +			break; +		} +		goto do_div; +	case BPF_ALU_DIV | BPF_K: +	case BPF_ALU_MOD | BPF_K: +		if (K == 0) { +			set_return(r); +			break; +		} +do_div: +		switch (f->code) { +		case BPF_ALU_DIV | BPF_X: +			r->A /= r->X; +			break; +		case BPF_ALU_DIV | BPF_K: +			r->A /= K; +			break; +		case BPF_ALU_MOD | BPF_X: +			r->A %= r->X; +			break; +		case BPF_ALU_MOD | BPF_K: +			r->A %= K; +			break; +		} +		break; +	case BPF_ALU_AND | BPF_X: +		r->A &= r->X; +		break; +	case BPF_ALU_AND | BPF_K: +		r->A &= K; +		break; +	case BPF_ALU_OR | BPF_X: +		r->A |= r->X; +		break; +	case BPF_ALU_OR | BPF_K: +		r->A |= K; +		break; +	case BPF_ALU_XOR | BPF_X: +		r->A ^= r->X; +		break; +	case BPF_ALU_XOR | BPF_K: +		r->A ^= K; +		break; +	} +} + +static bool bpf_pc_has_breakpoint(uint16_t pc) +{ +	int i; + +	for (i = 0; i < array_size(bpf_breakpoints); i++) { +		if (bpf_breakpoints[i] < 0) +			continue; +		if (bpf_breakpoints[i] == pc) +			return true; +	} + +	return false; +} + +static bool bpf_handle_breakpoint(struct bpf_regs *r, struct sock_filter *f, +				  uint8_t *pkt, uint32_t pkt_caplen, +				  uint32_t pkt_len) +{ +	rl_printf("-- register dump --\n"); +	bpf_dump_curr(r, &f[r->Pc]); +	rl_printf("-- packet dump --\n"); +	bpf_dump_pkt(pkt, pkt_caplen, pkt_len); +	rl_printf("(breakpoint)\n"); +	return true; +} + +static int bpf_run_all(struct sock_filter *f, uint16_t bpf_len, uint8_t *pkt, +		       uint32_t pkt_caplen, uint32_t pkt_len) +{ +	bool stop = false; + +	while (bpf_curr.Rs == false && stop == false) { +		bpf_safe_regs(); + +		if (bpf_pc_has_breakpoint(bpf_curr.Pc)) +			stop = bpf_handle_breakpoint(&bpf_curr, f, pkt, +						     pkt_caplen, pkt_len); + +		bpf_single_step(&bpf_curr, &f[bpf_curr.Pc], pkt, pkt_caplen, +				pkt_len); +		bpf_curr.Pc++; +	} + +	return stop ? -1 : bpf_curr.R; +} + +static int bpf_run_stepping(struct sock_filter *f, uint16_t bpf_len, +			    uint8_t *pkt, uint32_t pkt_caplen, +			    uint32_t pkt_len, int next) +{ +	bool stop = false; +	int i = 1; + +	while (bpf_curr.Rs == false && stop == false) { +		bpf_safe_regs(); + +		if (i++ == next) +			stop = bpf_handle_breakpoint(&bpf_curr, f, pkt, +						     pkt_caplen, pkt_len); + +		bpf_single_step(&bpf_curr, &f[bpf_curr.Pc], pkt, pkt_caplen, +				pkt_len); +		bpf_curr.Pc++; +	} + +	return stop ? -1 : bpf_curr.R; +} + +static bool pcap_loaded(void) +{ +	if (pcap_fd < 0) +		rl_printf("no pcap file loaded!\n"); + +	return pcap_fd >= 0; +} + +static struct pcap_pkthdr *pcap_curr_pkt(void) +{ +	return (void *) pcap_ptr_va_curr; +} + +static bool pcap_next_pkt(void) +{ +	struct pcap_pkthdr *hdr = pcap_curr_pkt(); + +	if (pcap_ptr_va_curr + sizeof(*hdr) - +	    pcap_ptr_va_start >= pcap_map_size) +		return false; +	if (hdr->caplen == 0 || hdr->len == 0 || hdr->caplen > hdr->len) +		return false; +	if (pcap_ptr_va_curr + sizeof(*hdr) + hdr->caplen - +	    pcap_ptr_va_start >= pcap_map_size) +		return false; + +	pcap_ptr_va_curr += (sizeof(*hdr) + hdr->caplen); +	return true; +} + +static void pcap_reset_pkt(void) +{ +	pcap_ptr_va_curr = pcap_ptr_va_start + sizeof(struct pcap_filehdr); +} + +static int try_load_pcap(const char *file) +{ +	struct pcap_filehdr *hdr; +	struct stat sb; +	int ret; + +	pcap_fd = open(file, O_RDONLY); +	if (pcap_fd < 0) { +		rl_printf("cannot open pcap [%s]!\n", strerror(errno)); +		return CMD_ERR; +	} + +	ret = fstat(pcap_fd, &sb); +	if (ret < 0) { +		rl_printf("cannot fstat pcap file!\n"); +		return CMD_ERR; +	} + +	if (!S_ISREG(sb.st_mode)) { +		rl_printf("not a regular pcap file, duh!\n"); +		return CMD_ERR; +	} + +	pcap_map_size = sb.st_size; +	if (pcap_map_size <= sizeof(struct pcap_filehdr)) { +		rl_printf("pcap file too small!\n"); +		return CMD_ERR; +	} + +	pcap_ptr_va_start = mmap(NULL, pcap_map_size, PROT_READ, +				 MAP_SHARED | MAP_LOCKED, pcap_fd, 0); +	if (pcap_ptr_va_start == MAP_FAILED) { +		rl_printf("mmap of file failed!"); +		return CMD_ERR; +	} + +	hdr = (void *) pcap_ptr_va_start; +	if (hdr->magic != TCPDUMP_MAGIC) { +		rl_printf("wrong pcap magic!\n"); +		return CMD_ERR; +	} + +	pcap_reset_pkt(); + +	return CMD_OK; + +} + +static void try_close_pcap(void) +{ +	if (pcap_fd >= 0) { +		munmap(pcap_ptr_va_start, pcap_map_size); +		close(pcap_fd); + +		pcap_ptr_va_start = pcap_ptr_va_curr = NULL; +		pcap_map_size = 0; +		pcap_packet = 0; +		pcap_fd = -1; +	} +} + +static int cmd_load_bpf(char *bpf_string) +{ +	char sp, *token, separator = ','; +	unsigned short bpf_len, i = 0; +	struct sock_filter tmp; + +	bpf_prog_len = 0; +	memset(bpf_image, 0, sizeof(bpf_image)); + +	if (sscanf(bpf_string, "%hu%c", &bpf_len, &sp) != 2 || +	    sp != separator || bpf_len > BPF_MAXINSNS || bpf_len == 0) { +		rl_printf("syntax error in head length encoding!\n"); +		return CMD_ERR; +	} + +	token = bpf_string; +	while ((token = strchr(token, separator)) && (++token)[0]) { +		if (i >= bpf_len) { +			rl_printf("program exceeds encoded length!\n"); +			return CMD_ERR; +		} + +		if (sscanf(token, "%hu %hhu %hhu %u,", +			   &tmp.code, &tmp.jt, &tmp.jf, &tmp.k) != 4) { +			rl_printf("syntax error at instruction %d!\n", i); +			return CMD_ERR; +		} + +		bpf_image[i].code = tmp.code; +		bpf_image[i].jt = tmp.jt; +		bpf_image[i].jf = tmp.jf; +		bpf_image[i].k = tmp.k; + +		i++; +	} + +	if (i != bpf_len) { +		rl_printf("syntax error exceeding encoded length!\n"); +		return CMD_ERR; +	} else +		bpf_prog_len = bpf_len; +	if (!bpf_runnable(bpf_image, bpf_prog_len)) +		bpf_prog_len = 0; + +	return CMD_OK; +} + +static int cmd_load_pcap(char *file) +{ +	char *file_trim, *tmp; + +	file_trim = strtok_r(file, " ", &tmp); +	if (file_trim == NULL) +		return CMD_ERR; + +	try_close_pcap(); + +	return try_load_pcap(file_trim); +} + +static int cmd_load(char *arg) +{ +	char *subcmd, *cont, *tmp = strdup(arg); +	int ret = CMD_OK; + +	subcmd = strtok_r(tmp, " ", &cont); +	if (subcmd == NULL) +		goto out; +	if (matches(subcmd, "bpf") == 0) { +		bpf_reset(); +		bpf_reset_breakpoints(); + +		ret = cmd_load_bpf(cont); +	} else if (matches(subcmd, "pcap") == 0) { +		ret = cmd_load_pcap(cont); +	} else { +out: +		rl_printf("bpf <code>:  load bpf code\n"); +		rl_printf("pcap <file>: load pcap file\n"); +		ret = CMD_ERR; +	} + +	free(tmp); +	return ret; +} + +static int cmd_step(char *num) +{ +	struct pcap_pkthdr *hdr; +	int steps, ret; + +	if (!bpf_prog_loaded() || !pcap_loaded()) +		return CMD_ERR; + +	steps = strtol(num, NULL, 10); +	if (steps == 0 || strlen(num) == 0) +		steps = 1; +	if (steps < 0) { +		if (!bpf_restore_regs(steps)) +			return CMD_ERR; +		steps = 1; +	} + +	hdr = pcap_curr_pkt(); +	ret = bpf_run_stepping(bpf_image, bpf_prog_len, +			       (uint8_t *) hdr + sizeof(*hdr), +			       hdr->caplen, hdr->len, steps); +	if (ret >= 0 || bpf_curr.Rs) { +		bpf_reset(); +		if (!pcap_next_pkt()) { +			rl_printf("(going back to first packet)\n"); +			pcap_reset_pkt(); +		} else { +			rl_printf("(next packet)\n"); +		} +	} + +	return CMD_OK; +} + +static int cmd_select(char *num) +{ +	unsigned int which, i; +	bool have_next = true; + +	if (!pcap_loaded() || strlen(num) == 0) +		return CMD_ERR; + +	which = strtoul(num, NULL, 10); +	if (which == 0) { +		rl_printf("packet count starts with 1, clamping!\n"); +		which = 1; +	} + +	pcap_reset_pkt(); +	bpf_reset(); + +	for (i = 0; i < which && (have_next = pcap_next_pkt()); i++) +		/* noop */; +	if (!have_next || pcap_curr_pkt() == NULL) { +		rl_printf("no packet #%u available!\n", which); +		pcap_reset_pkt(); +		return CMD_ERR; +	} + +	return CMD_OK; +} + +static int cmd_breakpoint(char *subcmd) +{ +	if (!bpf_prog_loaded()) +		return CMD_ERR; +	if (strlen(subcmd) == 0) +		bpf_dump_breakpoints(); +	else if (matches(subcmd, "reset") == 0) +		bpf_reset_breakpoints(); +	else { +		unsigned int where = strtoul(subcmd, NULL, 10); + +		if (where < bpf_prog_len) { +			bpf_set_breakpoints(where); +			rl_printf("breakpoint at: "); +			bpf_disasm(bpf_image[where], where); +		} +	} + +	return CMD_OK; +} + +static int cmd_run(char *num) +{ +	static uint32_t pass = 0, fail = 0; +	bool has_limit = true; +	int pkts = 0, i = 0; + +	if (!bpf_prog_loaded() || !pcap_loaded()) +		return CMD_ERR; + +	pkts = strtol(num, NULL, 10); +	if (pkts == 0 || strlen(num) == 0) +		has_limit = false; + +	do { +		struct pcap_pkthdr *hdr = pcap_curr_pkt(); +		int ret = bpf_run_all(bpf_image, bpf_prog_len, +				      (uint8_t *) hdr + sizeof(*hdr), +				      hdr->caplen, hdr->len); +		if (ret > 0) +			pass++; +		else if (ret == 0) +			fail++; +		else +			return CMD_OK; +		bpf_reset(); +	} while (pcap_next_pkt() && (!has_limit || (has_limit && ++i < pkts))); + +	rl_printf("bpf passes:%u fails:%u\n", pass, fail); + +	pcap_reset_pkt(); +	bpf_reset(); + +	pass = fail = 0; +	return CMD_OK; +} + +static int cmd_disassemble(char *line_string) +{ +	bool single_line = false; +	unsigned long line; + +	if (!bpf_prog_loaded()) +		return CMD_ERR; +	if (strlen(line_string) > 0 && +	    (line = strtoul(line_string, NULL, 10)) < bpf_prog_len) +		single_line = true; +	if (single_line) +		bpf_disasm(bpf_image[line], line); +	else +		bpf_disasm_all(bpf_image, bpf_prog_len); + +	return CMD_OK; +} + +static int cmd_dump(char *dontcare) +{ +	if (!bpf_prog_loaded()) +		return CMD_ERR; + +	bpf_dump_all(bpf_image, bpf_prog_len); + +	return CMD_OK; +} + +static int cmd_quit(char *dontcare) +{ +	return CMD_EX; +} + +static const struct shell_cmd cmds[] = { +	{ .name = "load", .func = cmd_load }, +	{ .name = "select", .func = cmd_select }, +	{ .name = "step", .func = cmd_step }, +	{ .name = "run", .func = cmd_run }, +	{ .name = "breakpoint", .func = cmd_breakpoint }, +	{ .name = "disassemble", .func = cmd_disassemble }, +	{ .name = "dump", .func = cmd_dump }, +	{ .name = "quit", .func = cmd_quit }, +}; + +static int execf(char *arg) +{ +	char *cmd, *cont, *tmp = strdup(arg); +	int i, ret = 0, len; + +	cmd = strtok_r(tmp, " ", &cont); +	if (cmd == NULL) +		goto out; +	len = strlen(cmd); +	for (i = 0; i < array_size(cmds); i++) { +		if (len != strlen(cmds[i].name)) +			continue; +		if (strncmp(cmds[i].name, cmd, len) == 0) { +			ret = cmds[i].func(cont); +			break; +		} +	} +out: +	free(tmp); +	return ret; +} + +static char *shell_comp_gen(const char *buf, int state) +{ +	static int list_index, len; + +	if (!state) { +		list_index = 0; +		len = strlen(buf); +	} + +	for (; list_index < array_size(cmds); ) { +		const char *name = cmds[list_index].name; + +		list_index++; +		if (strncmp(name, buf, len) == 0) +			return strdup(name); +	} + +	return NULL; +} + +static char **shell_completion(const char *buf, int start, int end) +{ +	char **matches = NULL; + +	if (start == 0) +		matches = rl_completion_matches(buf, shell_comp_gen); + +	return matches; +} + +static void intr_shell(int sig) +{ +	if (rl_end) +		rl_kill_line(-1, 0); + +	rl_crlf(); +	rl_refresh_line(0, 0); +	rl_free_line_state(); +} + +static void init_shell(FILE *fin, FILE *fout) +{ +	char file[128]; + +	snprintf(file, sizeof(file), "%s/.bpf_dbg_history", getenv("HOME")); +	read_history(file); + +	rl_instream = fin; +	rl_outstream = fout; + +	rl_readline_name = "bpf_dbg"; +	rl_terminal_name = getenv("TERM"); + +	rl_catch_signals = 0; +	rl_catch_sigwinch = 1; + +	rl_attempted_completion_function = shell_completion; + +	rl_bind_key('\t', rl_complete); + +	rl_bind_key_in_map('\t', rl_complete, emacs_meta_keymap); +	rl_bind_key_in_map('\033', rl_complete, emacs_meta_keymap); + +	snprintf(file, sizeof(file), "%s/.bpf_dbg_init", getenv("HOME")); +	rl_read_init_file(file); + +	rl_prep_terminal(0); +	rl_set_signals(); + +	signal(SIGINT, intr_shell); +} + +static void exit_shell(FILE *fin, FILE *fout) +{ +	char file[128]; + +	snprintf(file, sizeof(file), "%s/.bpf_dbg_history", getenv("HOME")); +	write_history(file); + +	clear_history(); +	rl_deprep_terminal(); + +	try_close_pcap(); + +	if (fin != stdin) +		fclose(fin); +	if (fout != stdout) +		fclose(fout); +} + +static int run_shell_loop(FILE *fin, FILE *fout) +{ +	char *buf; + +	init_shell(fin, fout); + +	while ((buf = readline("> ")) != NULL) { +		int ret = execf(buf); +		if (ret == CMD_EX) +			break; +		if (ret == CMD_OK && strlen(buf) > 0) +			add_history(buf); + +		free(buf); +	} + +	exit_shell(fin, fout); +	return 0; +} + +int main(int argc, char **argv) +{ +	FILE *fin = NULL, *fout = NULL; + +	if (argc >= 2) +		fin = fopen(argv[1], "r"); +	if (argc >= 3) +		fout = fopen(argv[2], "w"); + +	return run_shell_loop(fin ? : stdin, fout ? : stdout); +} diff --git a/tools/net/bpf_exp.l b/tools/net/bpf_exp.l new file mode 100644 index 00000000000..833a96611da --- /dev/null +++ b/tools/net/bpf_exp.l @@ -0,0 +1,144 @@ +/* + * BPF asm code lexer + * + * This program is free software; you can distribute it and/or modify + * it under the terms of the GNU General Public License as published + * by the Free Software Foundation; either version 2 of the License, + * or (at your option) any later version. + * + * Syntax kept close to: + * + * Steven McCanne and Van Jacobson. 1993. The BSD packet filter: a new + * architecture for user-level packet capture. In Proceedings of the + * USENIX Winter 1993 Conference Proceedings on USENIX Winter 1993 + * Conference Proceedings (USENIX'93). USENIX Association, Berkeley, + * CA, USA, 2-2. + * + * Copyright 2013 Daniel Borkmann <borkmann@redhat.com> + * Licensed under the GNU General Public License, version 2.0 (GPLv2) + */ + +%{ + +#include <stdio.h> +#include <stdint.h> +#include <stdlib.h> + +#include "bpf_exp.yacc.h" + +extern void yyerror(const char *str); + +%} + +%option align +%option ecs + +%option nounput +%option noreject +%option noinput +%option noyywrap + +%option 8bit +%option caseless +%option yylineno + +%% + +"ldb"		{ return OP_LDB; } +"ldh"		{ return OP_LDH; } +"ld"		{ return OP_LD; } +"ldi"		{ return OP_LDI; } +"ldx"		{ return OP_LDX; } +"ldxi"		{ return OP_LDXI; } +"ldxb"		{ return OP_LDXB; } +"st"		{ return OP_ST; } +"stx"		{ return OP_STX; } +"jmp"		{ return OP_JMP; } +"ja"		{ return OP_JMP; } +"jeq"		{ return OP_JEQ; } +"jneq"		{ return OP_JNEQ; } +"jne"		{ return OP_JNEQ; } +"jlt"		{ return OP_JLT; } +"jle"		{ return OP_JLE; } +"jgt"		{ return OP_JGT; } +"jge"		{ return OP_JGE; } +"jset"		{ return OP_JSET; } +"add"		{ return OP_ADD; } +"sub"		{ return OP_SUB; } +"mul"		{ return OP_MUL; } +"div"		{ return OP_DIV; } +"mod"		{ return OP_MOD; } +"neg"		{ return OP_NEG; } +"and"		{ return OP_AND; } +"xor"		{ return OP_XOR; } +"or"		{ return OP_OR; } +"lsh"		{ return OP_LSH; } +"rsh"		{ return OP_RSH; } +"ret"		{ return OP_RET; } +"tax"		{ return OP_TAX; } +"txa"		{ return OP_TXA; } + +"#"?("len")	{ return K_PKT_LEN; } +"#"?("proto")	{ return K_PROTO; } +"#"?("type")	{ return K_TYPE; } +"#"?("poff")	{ return K_POFF; } +"#"?("ifidx")	{ return K_IFIDX; } +"#"?("nla")	{ return K_NLATTR; } +"#"?("nlan")	{ return K_NLATTR_NEST; } +"#"?("mark")	{ return K_MARK; } +"#"?("queue")	{ return K_QUEUE; } +"#"?("hatype")	{ return K_HATYPE; } +"#"?("rxhash")	{ return K_RXHASH; } +"#"?("cpu")	{ return K_CPU; } +"#"?("vlan_tci") { return K_VLANT; } +"#"?("vlan_pr")	{ return K_VLANP; } +"#"?("rand")	{ return K_RAND; } + +":"		{ return ':'; } +","		{ return ','; } +"#"		{ return '#'; } +"%"		{ return '%'; } +"["		{ return '['; } +"]"		{ return ']'; } +"("		{ return '('; } +")"		{ return ')'; } +"x"		{ return 'x'; } +"a"		{ return 'a'; } +"+"		{ return '+'; } +"M"		{ return 'M'; } +"*"		{ return '*'; } +"&"		{ return '&'; } + +([0][x][a-fA-F0-9]+) { +			yylval.number = strtoul(yytext, NULL, 16); +			return number; +		} +([0][b][0-1]+)	{ +			yylval.number = strtol(yytext + 2, NULL, 2); +			return number; +		} +(([0])|([-+]?[1-9][0-9]*)) { +			yylval.number = strtol(yytext, NULL, 10); +			return number; +		} +([0][0-9]+)	{ +			yylval.number = strtol(yytext + 1, NULL, 8); +			return number; +		} +[a-zA-Z_][a-zA-Z0-9_]+ { +			yylval.label = strdup(yytext); +			return label; +		} + +"/*"([^\*]|\*[^/])*"*/"		{ /* NOP */ } +";"[^\n]*			{ /* NOP */ } +^#.*				{ /* NOP */ } +[ \t]+				{ /* NOP */ } +[ \n]+				{ /* NOP */ } + +.		{ +			printf("unknown character \'%s\'", yytext); +			yyerror("lex unknown character"); +		} + +%% diff --git a/tools/net/bpf_exp.y b/tools/net/bpf_exp.y new file mode 100644 index 00000000000..e6306c51c26 --- /dev/null +++ b/tools/net/bpf_exp.y @@ -0,0 +1,771 @@ +/* + * BPF asm code parser + * + * This program is free software; you can distribute it and/or modify + * it under the terms of the GNU General Public License as published + * by the Free Software Foundation; either version 2 of the License, + * or (at your option) any later version. + * + * Syntax kept close to: + * + * Steven McCanne and Van Jacobson. 1993. The BSD packet filter: a new + * architecture for user-level packet capture. In Proceedings of the + * USENIX Winter 1993 Conference Proceedings on USENIX Winter 1993 + * Conference Proceedings (USENIX'93). USENIX Association, Berkeley, + * CA, USA, 2-2. + * + * Copyright 2013 Daniel Borkmann <borkmann@redhat.com> + * Licensed under the GNU General Public License, version 2.0 (GPLv2) + */ + +%{ + +#include <stdio.h> +#include <string.h> +#include <stdint.h> +#include <stdlib.h> +#include <stdbool.h> +#include <unistd.h> +#include <errno.h> +#include <assert.h> +#include <linux/filter.h> + +#include "bpf_exp.yacc.h" + +enum jmp_type { JTL, JFL, JKL }; + +extern FILE *yyin; +extern int yylex(void); +extern void yyerror(const char *str); + +extern void bpf_asm_compile(FILE *fp, bool cstyle); +static void bpf_set_curr_instr(uint16_t op, uint8_t jt, uint8_t jf, uint32_t k); +static void bpf_set_curr_label(char *label); +static void bpf_set_jmp_label(char *label, enum jmp_type type); + +%} + +%union { +	char *label; +	uint32_t number; +} + +%token OP_LDB OP_LDH OP_LD OP_LDX OP_ST OP_STX OP_JMP OP_JEQ OP_JGT OP_JGE +%token OP_JSET OP_ADD OP_SUB OP_MUL OP_DIV OP_AND OP_OR OP_XOR OP_LSH OP_RSH +%token OP_RET OP_TAX OP_TXA OP_LDXB OP_MOD OP_NEG OP_JNEQ OP_JLT OP_JLE OP_LDI +%token OP_LDXI + +%token K_PKT_LEN K_PROTO K_TYPE K_NLATTR K_NLATTR_NEST K_MARK K_QUEUE K_HATYPE +%token K_RXHASH K_CPU K_IFIDX K_VLANT K_VLANP K_POFF K_RAND + +%token ':' ',' '[' ']' '(' ')' 'x' 'a' '+' 'M' '*' '&' '#' '%' + +%token number label + +%type <label> label +%type <number> number + +%% + +prog +	: line +	| prog line +	; + +line +	: instr +	| labelled_instr +	; + +labelled_instr +	: labelled instr +	; + +instr +	: ldb +	| ldh +	| ld +	| ldi +	| ldx +	| ldxi +	| st +	| stx +	| jmp +	| jeq +	| jneq +	| jlt +	| jle +	| jgt +	| jge +	| jset +	| add +	| sub +	| mul +	| div +	| mod +	| neg +	| and +	| or +	| xor +	| lsh +	| rsh +	| ret +	| tax +	| txa +	; + +labelled +	: label ':' { bpf_set_curr_label($1); } +	; + +ldb +	: OP_LDB '[' 'x' '+' number ']' { +		bpf_set_curr_instr(BPF_LD | BPF_B | BPF_IND, 0, 0, $5); } +	| OP_LDB '[' '%' 'x' '+' number ']' { +		bpf_set_curr_instr(BPF_LD | BPF_B | BPF_IND, 0, 0, $6); } +	| OP_LDB '[' number ']' { +		bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, $3); } +	| OP_LDB K_PROTO { +		bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_PROTOCOL); } +	| OP_LDB K_TYPE { +		bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_PKTTYPE); } +	| OP_LDB K_IFIDX { +		bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_IFINDEX); } +	| OP_LDB K_NLATTR { +		bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_NLATTR); } +	| OP_LDB K_NLATTR_NEST { +		bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_NLATTR_NEST); } +	| OP_LDB K_MARK { +		bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_MARK); } +	| OP_LDB K_QUEUE { +		bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_QUEUE); } +	| OP_LDB K_HATYPE { +		bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_HATYPE); } +	| OP_LDB K_RXHASH { +		bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_RXHASH); } +	| OP_LDB K_CPU { +		bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_CPU); } +	| OP_LDB K_VLANT { +		bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_VLAN_TAG); } +	| OP_LDB K_VLANP { +		bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT); } +	| OP_LDB K_POFF { +		bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_PAY_OFFSET); } +	| OP_LDB K_RAND { +		bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_RANDOM); } +	; + +ldh +	: OP_LDH '[' 'x' '+' number ']' { +		bpf_set_curr_instr(BPF_LD | BPF_H | BPF_IND, 0, 0, $5); } +	| OP_LDH '[' '%' 'x' '+' number ']' { +		bpf_set_curr_instr(BPF_LD | BPF_H | BPF_IND, 0, 0, $6); } +	| OP_LDH '[' number ']' { +		bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, $3); } +	| OP_LDH K_PROTO { +		bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_PROTOCOL); } +	| OP_LDH K_TYPE { +		bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_PKTTYPE); } +	| OP_LDH K_IFIDX { +		bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_IFINDEX); } +	| OP_LDH K_NLATTR { +		bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_NLATTR); } +	| OP_LDH K_NLATTR_NEST { +		bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_NLATTR_NEST); } +	| OP_LDH K_MARK { +		bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_MARK); } +	| OP_LDH K_QUEUE { +		bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_QUEUE); } +	| OP_LDH K_HATYPE { +		bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_HATYPE); } +	| OP_LDH K_RXHASH { +		bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_RXHASH); } +	| OP_LDH K_CPU { +		bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_CPU); } +	| OP_LDH K_VLANT { +		bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_VLAN_TAG); } +	| OP_LDH K_VLANP { +		bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT); } +	| OP_LDH K_POFF { +		bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_PAY_OFFSET); } +	| OP_LDH K_RAND { +		bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_RANDOM); } +	; + +ldi +	: OP_LDI '#' number { +		bpf_set_curr_instr(BPF_LD | BPF_IMM, 0, 0, $3); } +	| OP_LDI number { +		bpf_set_curr_instr(BPF_LD | BPF_IMM, 0, 0, $2); } +	; + +ld +	: OP_LD '#' number { +		bpf_set_curr_instr(BPF_LD | BPF_IMM, 0, 0, $3); } +	| OP_LD K_PKT_LEN { +		bpf_set_curr_instr(BPF_LD | BPF_W | BPF_LEN, 0, 0, 0); } +	| OP_LD K_PROTO { +		bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_PROTOCOL); } +	| OP_LD K_TYPE { +		bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_PKTTYPE); } +	| OP_LD K_IFIDX { +		bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_IFINDEX); } +	| OP_LD K_NLATTR { +		bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_NLATTR); } +	| OP_LD K_NLATTR_NEST { +		bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_NLATTR_NEST); } +	| OP_LD K_MARK { +		bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_MARK); } +	| OP_LD K_QUEUE { +		bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_QUEUE); } +	| OP_LD K_HATYPE { +		bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_HATYPE); } +	| OP_LD K_RXHASH { +		bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_RXHASH); } +	| OP_LD K_CPU { +		bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_CPU); } +	| OP_LD K_VLANT { +		bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_VLAN_TAG); } +	| OP_LD K_VLANP { +		bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT); } +	| OP_LD K_POFF { +		bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_PAY_OFFSET); } +	| OP_LD K_RAND { +		bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, +				   SKF_AD_OFF + SKF_AD_RANDOM); } +	| OP_LD 'M' '[' number ']' { +		bpf_set_curr_instr(BPF_LD | BPF_MEM, 0, 0, $4); } +	| OP_LD '[' 'x' '+' number ']' { +		bpf_set_curr_instr(BPF_LD | BPF_W | BPF_IND, 0, 0, $5); } +	| OP_LD '[' '%' 'x' '+' number ']' { +		bpf_set_curr_instr(BPF_LD | BPF_W | BPF_IND, 0, 0, $6); } +	| OP_LD '[' number ']' { +		bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, $3); } +	; + +ldxi +	: OP_LDXI '#' number { +		bpf_set_curr_instr(BPF_LDX | BPF_IMM, 0, 0, $3); } +	| OP_LDXI number { +		bpf_set_curr_instr(BPF_LDX | BPF_IMM, 0, 0, $2); } +	; + +ldx +	: OP_LDX '#' number { +		bpf_set_curr_instr(BPF_LDX | BPF_IMM, 0, 0, $3); } +	| OP_LDX K_PKT_LEN { +		bpf_set_curr_instr(BPF_LDX | BPF_W | BPF_LEN, 0, 0, 0); } +	| OP_LDX 'M' '[' number ']' { +		bpf_set_curr_instr(BPF_LDX | BPF_MEM, 0, 0, $4); } +	| OP_LDXB number '*' '(' '[' number ']' '&' number ')' { +		if ($2 != 4 || $9 != 0xf) { +			fprintf(stderr, "ldxb offset not supported!\n"); +			exit(0); +		} else { +			bpf_set_curr_instr(BPF_LDX | BPF_MSH | BPF_B, 0, 0, $6); } } +	| OP_LDX number '*' '(' '[' number ']' '&' number ')' { +		if ($2 != 4 || $9 != 0xf) { +			fprintf(stderr, "ldxb offset not supported!\n"); +			exit(0); +		} else { +			bpf_set_curr_instr(BPF_LDX | BPF_MSH | BPF_B, 0, 0, $6); } } +	; + +st +	: OP_ST 'M' '[' number ']' { +		bpf_set_curr_instr(BPF_ST, 0, 0, $4); } +	; + +stx +	: OP_STX 'M' '[' number ']' { +		bpf_set_curr_instr(BPF_STX, 0, 0, $4); } +	; + +jmp +	: OP_JMP label { +		bpf_set_jmp_label($2, JKL); +		bpf_set_curr_instr(BPF_JMP | BPF_JA, 0, 0, 0); } +	; + +jeq +	: OP_JEQ '#' number ',' label ',' label { +		bpf_set_jmp_label($5, JTL); +		bpf_set_jmp_label($7, JFL); +		bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_K, 0, 0, $3); } +	| OP_JEQ 'x' ',' label ',' label { +		bpf_set_jmp_label($4, JTL); +		bpf_set_jmp_label($6, JFL); +		bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); } +	| OP_JEQ '%' 'x' ',' label ',' label { +		bpf_set_jmp_label($5, JTL); +		bpf_set_jmp_label($7, JFL); +		bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); } +	| OP_JEQ '#' number ',' label { +		bpf_set_jmp_label($5, JTL); +		bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_K, 0, 0, $3); } +	| OP_JEQ 'x' ',' label { +		bpf_set_jmp_label($4, JTL); +		bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); } +	| OP_JEQ '%' 'x' ',' label { +		bpf_set_jmp_label($5, JTL); +		bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); } +	; + +jneq +	: OP_JNEQ '#' number ',' label { +		bpf_set_jmp_label($5, JFL); +		bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_K, 0, 0, $3); } +	| OP_JNEQ 'x' ',' label { +		bpf_set_jmp_label($4, JFL); +		bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); } +	| OP_JNEQ '%' 'x' ',' label { +		bpf_set_jmp_label($5, JFL); +		bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); } +	; + +jlt +	: OP_JLT '#' number ',' label { +		bpf_set_jmp_label($5, JFL); +		bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_K, 0, 0, $3); } +	| OP_JLT 'x' ',' label { +		bpf_set_jmp_label($4, JFL); +		bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); } +	| OP_JLT '%' 'x' ',' label { +		bpf_set_jmp_label($5, JFL); +		bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); } +	; + +jle +	: OP_JLE '#' number ',' label { +		bpf_set_jmp_label($5, JFL); +		bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_K, 0, 0, $3); } +	| OP_JLE 'x' ',' label { +		bpf_set_jmp_label($4, JFL); +		bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); } +	| OP_JLE '%' 'x' ',' label { +		bpf_set_jmp_label($5, JFL); +		bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); } +	; + +jgt +	: OP_JGT '#' number ',' label ',' label { +		bpf_set_jmp_label($5, JTL); +		bpf_set_jmp_label($7, JFL); +		bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_K, 0, 0, $3); } +	| OP_JGT 'x' ',' label ',' label { +		bpf_set_jmp_label($4, JTL); +		bpf_set_jmp_label($6, JFL); +		bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); } +	| OP_JGT '%' 'x' ',' label ',' label { +		bpf_set_jmp_label($5, JTL); +		bpf_set_jmp_label($7, JFL); +		bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); } +	| OP_JGT '#' number ',' label { +		bpf_set_jmp_label($5, JTL); +		bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_K, 0, 0, $3); } +	| OP_JGT 'x' ',' label { +		bpf_set_jmp_label($4, JTL); +		bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); } +	| OP_JGT '%' 'x' ',' label { +		bpf_set_jmp_label($5, JTL); +		bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); } +	; + +jge +	: OP_JGE '#' number ',' label ',' label { +		bpf_set_jmp_label($5, JTL); +		bpf_set_jmp_label($7, JFL); +		bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_K, 0, 0, $3); } +	| OP_JGE 'x' ',' label ',' label { +		bpf_set_jmp_label($4, JTL); +		bpf_set_jmp_label($6, JFL); +		bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); } +	| OP_JGE '%' 'x' ',' label ',' label { +		bpf_set_jmp_label($5, JTL); +		bpf_set_jmp_label($7, JFL); +		bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); } +	| OP_JGE '#' number ',' label { +		bpf_set_jmp_label($5, JTL); +		bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_K, 0, 0, $3); } +	| OP_JGE 'x' ',' label { +		bpf_set_jmp_label($4, JTL); +		bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); } +	| OP_JGE '%' 'x' ',' label { +		bpf_set_jmp_label($5, JTL); +		bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); } +	; + +jset +	: OP_JSET '#' number ',' label ',' label { +		bpf_set_jmp_label($5, JTL); +		bpf_set_jmp_label($7, JFL); +		bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_K, 0, 0, $3); } +	| OP_JSET 'x' ',' label ',' label { +		bpf_set_jmp_label($4, JTL); +		bpf_set_jmp_label($6, JFL); +		bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_X, 0, 0, 0); } +	| OP_JSET '%' 'x' ',' label ',' label { +		bpf_set_jmp_label($5, JTL); +		bpf_set_jmp_label($7, JFL); +		bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_X, 0, 0, 0); } +	| OP_JSET '#' number ',' label { +		bpf_set_jmp_label($5, JTL); +		bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_K, 0, 0, $3); } +	| OP_JSET 'x' ',' label { +		bpf_set_jmp_label($4, JTL); +		bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_X, 0, 0, 0); } +	| OP_JSET '%' 'x' ',' label { +		bpf_set_jmp_label($5, JTL); +		bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_X, 0, 0, 0); } +	; + +add +	: OP_ADD '#' number { +		bpf_set_curr_instr(BPF_ALU | BPF_ADD | BPF_K, 0, 0, $3); } +	| OP_ADD 'x' { +		bpf_set_curr_instr(BPF_ALU | BPF_ADD | BPF_X, 0, 0, 0); } +	| OP_ADD '%' 'x' { +		bpf_set_curr_instr(BPF_ALU | BPF_ADD | BPF_X, 0, 0, 0); } +	; + +sub +	: OP_SUB '#' number { +		bpf_set_curr_instr(BPF_ALU | BPF_SUB | BPF_K, 0, 0, $3); } +	| OP_SUB 'x' { +		bpf_set_curr_instr(BPF_ALU | BPF_SUB | BPF_X, 0, 0, 0); } +	| OP_SUB '%' 'x' { +		bpf_set_curr_instr(BPF_ALU | BPF_SUB | BPF_X, 0, 0, 0); } +	; + +mul +	: OP_MUL '#' number { +		bpf_set_curr_instr(BPF_ALU | BPF_MUL | BPF_K, 0, 0, $3); } +	| OP_MUL 'x' { +		bpf_set_curr_instr(BPF_ALU | BPF_MUL | BPF_X, 0, 0, 0); } +	| OP_MUL '%' 'x' { +		bpf_set_curr_instr(BPF_ALU | BPF_MUL | BPF_X, 0, 0, 0); } +	; + +div +	: OP_DIV '#' number { +		bpf_set_curr_instr(BPF_ALU | BPF_DIV | BPF_K, 0, 0, $3); } +	| OP_DIV 'x' { +		bpf_set_curr_instr(BPF_ALU | BPF_DIV | BPF_X, 0, 0, 0); } +	| OP_DIV '%' 'x' { +		bpf_set_curr_instr(BPF_ALU | BPF_DIV | BPF_X, 0, 0, 0); } +	; + +mod +	: OP_MOD '#' number { +		bpf_set_curr_instr(BPF_ALU | BPF_MOD | BPF_K, 0, 0, $3); } +	| OP_MOD 'x' { +		bpf_set_curr_instr(BPF_ALU | BPF_MOD | BPF_X, 0, 0, 0); } +	| OP_MOD '%' 'x' { +		bpf_set_curr_instr(BPF_ALU | BPF_MOD | BPF_X, 0, 0, 0); } +	; + +neg +	: OP_NEG { +		bpf_set_curr_instr(BPF_ALU | BPF_NEG, 0, 0, 0); } +	; + +and +	: OP_AND '#' number { +		bpf_set_curr_instr(BPF_ALU | BPF_AND | BPF_K, 0, 0, $3); } +	| OP_AND 'x' { +		bpf_set_curr_instr(BPF_ALU | BPF_AND | BPF_X, 0, 0, 0); } +	| OP_AND '%' 'x' { +		bpf_set_curr_instr(BPF_ALU | BPF_AND | BPF_X, 0, 0, 0); } +	; + +or +	: OP_OR '#' number { +		bpf_set_curr_instr(BPF_ALU | BPF_OR | BPF_K, 0, 0, $3); } +	| OP_OR 'x' { +		bpf_set_curr_instr(BPF_ALU | BPF_OR | BPF_X, 0, 0, 0); } +	| OP_OR '%' 'x' { +		bpf_set_curr_instr(BPF_ALU | BPF_OR | BPF_X, 0, 0, 0); } +	; + +xor +	: OP_XOR '#' number { +		bpf_set_curr_instr(BPF_ALU | BPF_XOR | BPF_K, 0, 0, $3); } +	| OP_XOR 'x' { +		bpf_set_curr_instr(BPF_ALU | BPF_XOR | BPF_X, 0, 0, 0); } +	| OP_XOR '%' 'x' { +		bpf_set_curr_instr(BPF_ALU | BPF_XOR | BPF_X, 0, 0, 0); } +	; + +lsh +	: OP_LSH '#' number { +		bpf_set_curr_instr(BPF_ALU | BPF_LSH | BPF_K, 0, 0, $3); } +	| OP_LSH 'x' { +		bpf_set_curr_instr(BPF_ALU | BPF_LSH | BPF_X, 0, 0, 0); } +	| OP_LSH '%' 'x' { +		bpf_set_curr_instr(BPF_ALU | BPF_LSH | BPF_X, 0, 0, 0); } +	; + +rsh +	: OP_RSH '#' number { +		bpf_set_curr_instr(BPF_ALU | BPF_RSH | BPF_K, 0, 0, $3); } +	| OP_RSH 'x' { +		bpf_set_curr_instr(BPF_ALU | BPF_RSH | BPF_X, 0, 0, 0); } +	| OP_RSH '%' 'x' { +		bpf_set_curr_instr(BPF_ALU | BPF_RSH | BPF_X, 0, 0, 0); } +	; + +ret +	: OP_RET 'a' { +		bpf_set_curr_instr(BPF_RET | BPF_A, 0, 0, 0); } +	| OP_RET '%' 'a' { +		bpf_set_curr_instr(BPF_RET | BPF_A, 0, 0, 0); } +	| OP_RET 'x' { +		bpf_set_curr_instr(BPF_RET | BPF_X, 0, 0, 0); } +	| OP_RET '%' 'x' { +		bpf_set_curr_instr(BPF_RET | BPF_X, 0, 0, 0); } +	| OP_RET '#' number { +		bpf_set_curr_instr(BPF_RET | BPF_K, 0, 0, $3); } +	; + +tax +	: OP_TAX { +		bpf_set_curr_instr(BPF_MISC | BPF_TAX, 0, 0, 0); } +	; + +txa +	: OP_TXA { +		bpf_set_curr_instr(BPF_MISC | BPF_TXA, 0, 0, 0); } +	; + +%% + +static int curr_instr = 0; +static struct sock_filter out[BPF_MAXINSNS]; +static char **labels, **labels_jt, **labels_jf, **labels_k; + +static void bpf_assert_max(void) +{ +	if (curr_instr >= BPF_MAXINSNS) { +		fprintf(stderr, "only max %u insns allowed!\n", BPF_MAXINSNS); +		exit(0); +	} +} + +static void bpf_set_curr_instr(uint16_t code, uint8_t jt, uint8_t jf, +			       uint32_t k) +{ +	bpf_assert_max(); +	out[curr_instr].code = code; +	out[curr_instr].jt = jt; +	out[curr_instr].jf = jf; +	out[curr_instr].k = k; +	curr_instr++; +} + +static void bpf_set_curr_label(char *label) +{ +	bpf_assert_max(); +	labels[curr_instr] = label; +} + +static void bpf_set_jmp_label(char *label, enum jmp_type type) +{ +	bpf_assert_max(); +	switch (type) { +	case JTL: +		labels_jt[curr_instr] = label; +		break; +	case JFL: +		labels_jf[curr_instr] = label; +		break; +	case JKL: +		labels_k[curr_instr] = label; +		break; +	} +} + +static int bpf_find_insns_offset(const char *label) +{ +	int i, max = curr_instr, ret = -ENOENT; + +	for (i = 0; i < max; i++) { +		if (labels[i] && !strcmp(label, labels[i])) { +			ret = i; +			break; +		} +	} + +	if (ret == -ENOENT) { +		fprintf(stderr, "no such label \'%s\'!\n", label); +		exit(0); +	} + +	return ret; +} + +static void bpf_stage_1_insert_insns(void) +{ +	yyparse(); +} + +static void bpf_reduce_k_jumps(void) +{ +	int i; + +	for (i = 0; i < curr_instr; i++) { +		if (labels_k[i]) { +			int off = bpf_find_insns_offset(labels_k[i]); +			out[i].k = (uint32_t) (off - i - 1); +		} +	} +} + +static void bpf_reduce_jt_jumps(void) +{ +	int i; + +	for (i = 0; i < curr_instr; i++) { +		if (labels_jt[i]) { +			int off = bpf_find_insns_offset(labels_jt[i]); +			out[i].jt = (uint8_t) (off - i -1); +		} +	} +} + +static void bpf_reduce_jf_jumps(void) +{ +	int i; + +	for (i = 0; i < curr_instr; i++) { +		if (labels_jf[i]) { +			int off = bpf_find_insns_offset(labels_jf[i]); +			out[i].jf = (uint8_t) (off - i - 1); +		} +	} +} + +static void bpf_stage_2_reduce_labels(void) +{ +	bpf_reduce_k_jumps(); +	bpf_reduce_jt_jumps(); +	bpf_reduce_jf_jumps(); +} + +static void bpf_pretty_print_c(void) +{ +	int i; + +	for (i = 0; i < curr_instr; i++) +		printf("{ %#04x, %2u, %2u, %#010x },\n", out[i].code, +		       out[i].jt, out[i].jf, out[i].k); +} + +static void bpf_pretty_print(void) +{ +	int i; + +	printf("%u,", curr_instr); +	for (i = 0; i < curr_instr; i++) +		printf("%u %u %u %u,", out[i].code, +		       out[i].jt, out[i].jf, out[i].k); +	printf("\n"); +} + +static void bpf_init(void) +{ +	memset(out, 0, sizeof(out)); + +	labels = calloc(BPF_MAXINSNS, sizeof(*labels)); +	assert(labels); +	labels_jt = calloc(BPF_MAXINSNS, sizeof(*labels_jt)); +	assert(labels_jt); +	labels_jf = calloc(BPF_MAXINSNS, sizeof(*labels_jf)); +	assert(labels_jf); +	labels_k = calloc(BPF_MAXINSNS, sizeof(*labels_k)); +	assert(labels_k); +} + +static void bpf_destroy_labels(void) +{ +	int i; + +	for (i = 0; i < curr_instr; i++) { +		free(labels_jf[i]); +		free(labels_jt[i]); +		free(labels_k[i]); +		free(labels[i]); +	} +} + +static void bpf_destroy(void) +{ +	bpf_destroy_labels(); +	free(labels_jt); +	free(labels_jf); +	free(labels_k); +	free(labels); +} + +void bpf_asm_compile(FILE *fp, bool cstyle) +{ +	yyin = fp; + +	bpf_init(); +	bpf_stage_1_insert_insns(); +	bpf_stage_2_reduce_labels(); +	bpf_destroy(); + +	if (cstyle) +		bpf_pretty_print_c(); +	else +		bpf_pretty_print(); + +	if (fp != stdin) +		fclose(yyin); +} + +void yyerror(const char *str) +{ +	exit(1); +} diff --git a/tools/net/bpf_jit_disasm.c b/tools/net/bpf_jit_disasm.c index cfe0cdcda3d..c5baf9c591b 100644 --- a/tools/net/bpf_jit_disasm.c +++ b/tools/net/bpf_jit_disasm.c @@ -43,8 +43,7 @@ static void get_exec_path(char *tpath, size_t size)  	free(path);  } -static void get_asm_insns(uint8_t *image, size_t len, unsigned long base, -			  int opcodes) +static void get_asm_insns(uint8_t *image, size_t len, int opcodes)  {  	int count, i, pc = 0;  	char tpath[256]; @@ -107,13 +106,13 @@ static void put_klog_buff(char *buff)  }  static int get_last_jit_image(char *haystack, size_t hlen, -			      uint8_t *image, size_t ilen, -			      unsigned long *base) +			      uint8_t *image, size_t ilen)  {  	char *ptr, *pptr, *tmp;  	off_t off = 0;  	int ret, flen, proglen, pass, ulen = 0;  	regmatch_t pmatch[1]; +	unsigned long base;  	regex_t regex;  	if (hlen == 0) @@ -136,7 +135,7 @@ static int get_last_jit_image(char *haystack, size_t hlen,  	ptr = haystack + off - (pmatch[0].rm_eo - pmatch[0].rm_so);  	ret = sscanf(ptr, "flen=%d proglen=%d pass=%d image=%lx", -		     &flen, &proglen, &pass, base); +		     &flen, &proglen, &pass, &base);  	if (ret != 4)  		return 0; @@ -162,7 +161,7 @@ static int get_last_jit_image(char *haystack, size_t hlen,  	assert(ulen == proglen);  	printf("%d bytes emitted from JIT compiler (pass:%d, flen:%d)\n",  	       proglen, pass, flen); -	printf("%lx + <x>:\n", *base); +	printf("%lx + <x>:\n", base);  	regfree(®ex);  	return ulen; @@ -172,8 +171,7 @@ int main(int argc, char **argv)  {  	int len, klen, opcodes = 0;  	char *kbuff; -	unsigned long base; -	uint8_t image[4096]; +	static uint8_t image[32768];  	if (argc > 1) {  		if (!strncmp("-o", argv[argc - 1], 2)) { @@ -189,9 +187,9 @@ int main(int argc, char **argv)  	kbuff = get_klog_buff(&klen); -	len = get_last_jit_image(kbuff, klen, image, sizeof(image), &base); -	if (len > 0 && base > 0) -		get_asm_insns(image, len, base, opcodes); +	len = get_last_jit_image(kbuff, klen, image, sizeof(image)); +	if (len > 0) +		get_asm_insns(image, len, opcodes);  	put_klog_buff(kbuff);  | 
