From b66e907cfee240a09a4b5aabf950a0d4c8da8d32 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Mon, 23 Oct 2017 09:24:05 -0700 Subject: tools: bpftool: copy JSON writer from iproute2 repository In prevision of following commits, supposed to add JSON output to the tool, two files are copied from the iproute2 repository (taken at commit 268a9eee985f): lib/json_writer.c and include/json_writer.h. Signed-off-by: Quentin Monnet Acked-by: Daniel Borkmann Signed-off-by: David S. Miller --- tools/bpf/bpftool/json_writer.c | 348 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 348 insertions(+) create mode 100644 tools/bpf/bpftool/json_writer.c (limited to 'tools/bpf/bpftool/json_writer.c') diff --git a/tools/bpf/bpftool/json_writer.c b/tools/bpf/bpftool/json_writer.c new file mode 100644 index 000000000000..6b77d288cce2 --- /dev/null +++ b/tools/bpf/bpftool/json_writer.c @@ -0,0 +1,348 @@ +/* + * Simple streaming JSON writer + * + * This takes care of the annoying bits of JSON syntax like the commas + * after elements + * + * This program is free software; you can redistribute 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. + * + * Authors: Stephen Hemminger + */ + +#include +#include +#include +#include +#include +#include +#include + +#include "json_writer.h" + +struct json_writer { + FILE *out; /* output file */ + unsigned depth; /* nesting */ + bool pretty; /* optional whitepace */ + char sep; /* either nul or comma */ +}; + +/* indentation for pretty print */ +static void jsonw_indent(json_writer_t *self) +{ + unsigned i; + for (i = 0; i < self->depth; ++i) + fputs(" ", self->out); +} + +/* end current line and indent if pretty printing */ +static void jsonw_eol(json_writer_t *self) +{ + if (!self->pretty) + return; + + putc('\n', self->out); + jsonw_indent(self); +} + +/* If current object is not empty print a comma */ +static void jsonw_eor(json_writer_t *self) +{ + if (self->sep != '\0') + putc(self->sep, self->out); + self->sep = ','; +} + + +/* Output JSON encoded string */ +/* Handles C escapes, does not do Unicode */ +static void jsonw_puts(json_writer_t *self, const char *str) +{ + putc('"', self->out); + for (; *str; ++str) + switch (*str) { + case '\t': + fputs("\\t", self->out); + break; + case '\n': + fputs("\\n", self->out); + break; + case '\r': + fputs("\\r", self->out); + break; + case '\f': + fputs("\\f", self->out); + break; + case '\b': + fputs("\\b", self->out); + break; + case '\\': + fputs("\\n", self->out); + break; + case '"': + fputs("\\\"", self->out); + break; + case '\'': + fputs("\\\'", self->out); + break; + default: + putc(*str, self->out); + } + putc('"', self->out); +} + +/* Create a new JSON stream */ +json_writer_t *jsonw_new(FILE *f) +{ + json_writer_t *self = malloc(sizeof(*self)); + if (self) { + self->out = f; + self->depth = 0; + self->pretty = false; + self->sep = '\0'; + } + return self; +} + +/* End output to JSON stream */ +void jsonw_destroy(json_writer_t **self_p) +{ + json_writer_t *self = *self_p; + + assert(self->depth == 0); + fputs("\n", self->out); + fflush(self->out); + free(self); + *self_p = NULL; +} + +void jsonw_pretty(json_writer_t *self, bool on) +{ + self->pretty = on; +} + +/* Basic blocks */ +static void jsonw_begin(json_writer_t *self, int c) +{ + jsonw_eor(self); + putc(c, self->out); + ++self->depth; + self->sep = '\0'; +} + +static void jsonw_end(json_writer_t *self, int c) +{ + assert(self->depth > 0); + + --self->depth; + if (self->sep != '\0') + jsonw_eol(self); + putc(c, self->out); + self->sep = ','; +} + + +/* Add a JSON property name */ +void jsonw_name(json_writer_t *self, const char *name) +{ + jsonw_eor(self); + jsonw_eol(self); + self->sep = '\0'; + jsonw_puts(self, name); + putc(':', self->out); + if (self->pretty) + putc(' ', self->out); +} + +void jsonw_printf(json_writer_t *self, const char *fmt, ...) +{ + va_list ap; + + va_start(ap, fmt); + jsonw_eor(self); + vfprintf(self->out, fmt, ap); + va_end(ap); +} + +/* Collections */ +void jsonw_start_object(json_writer_t *self) +{ + jsonw_begin(self, '{'); +} + +void jsonw_end_object(json_writer_t *self) +{ + jsonw_end(self, '}'); +} + +void jsonw_start_array(json_writer_t *self) +{ + jsonw_begin(self, '['); +} + +void jsonw_end_array(json_writer_t *self) +{ + jsonw_end(self, ']'); +} + +/* JSON value types */ +void jsonw_string(json_writer_t *self, const char *value) +{ + jsonw_eor(self); + jsonw_puts(self, value); +} + +void jsonw_bool(json_writer_t *self, bool val) +{ + jsonw_printf(self, "%s", val ? "true" : "false"); +} + +void jsonw_null(json_writer_t *self) +{ + jsonw_printf(self, "null"); +} + +void jsonw_float_fmt(json_writer_t *self, const char *fmt, double num) +{ + jsonw_printf(self, fmt, num); +} + +#ifdef notused +void jsonw_float(json_writer_t *self, double num) +{ + jsonw_printf(self, "%g", num); +} +#endif + +void jsonw_hu(json_writer_t *self, unsigned short num) +{ + jsonw_printf(self, "%hu", num); +} + +void jsonw_uint(json_writer_t *self, uint64_t num) +{ + jsonw_printf(self, "%"PRIu64, num); +} + +void jsonw_lluint(json_writer_t *self, unsigned long long int num) +{ + jsonw_printf(self, "%llu", num); +} + +void jsonw_int(json_writer_t *self, int64_t num) +{ + jsonw_printf(self, "%"PRId64, num); +} + +/* Basic name/value objects */ +void jsonw_string_field(json_writer_t *self, const char *prop, const char *val) +{ + jsonw_name(self, prop); + jsonw_string(self, val); +} + +void jsonw_bool_field(json_writer_t *self, const char *prop, bool val) +{ + jsonw_name(self, prop); + jsonw_bool(self, val); +} + +#ifdef notused +void jsonw_float_field(json_writer_t *self, const char *prop, double val) +{ + jsonw_name(self, prop); + jsonw_float(self, val); +} +#endif + +void jsonw_float_field_fmt(json_writer_t *self, + const char *prop, + const char *fmt, + double val) +{ + jsonw_name(self, prop); + jsonw_float_fmt(self, fmt, val); +} + +void jsonw_uint_field(json_writer_t *self, const char *prop, uint64_t num) +{ + jsonw_name(self, prop); + jsonw_uint(self, num); +} + +void jsonw_hu_field(json_writer_t *self, const char *prop, unsigned short num) +{ + jsonw_name(self, prop); + jsonw_hu(self, num); +} + +void jsonw_lluint_field(json_writer_t *self, + const char *prop, + unsigned long long int num) +{ + jsonw_name(self, prop); + jsonw_lluint(self, num); +} + +void jsonw_int_field(json_writer_t *self, const char *prop, int64_t num) +{ + jsonw_name(self, prop); + jsonw_int(self, num); +} + +void jsonw_null_field(json_writer_t *self, const char *prop) +{ + jsonw_name(self, prop); + jsonw_null(self); +} + +#ifdef TEST +int main(int argc, char **argv) +{ + json_writer_t *wr = jsonw_new(stdout); + + jsonw_start_object(wr); + jsonw_pretty(wr, true); + jsonw_name(wr, "Vyatta"); + jsonw_start_object(wr); + jsonw_string_field(wr, "url", "http://vyatta.com"); + jsonw_uint_field(wr, "downloads", 2000000ul); + jsonw_float_field(wr, "stock", 8.16); + + jsonw_name(wr, "ARGV"); + jsonw_start_array(wr); + while (--argc) + jsonw_string(wr, *++argv); + jsonw_end_array(wr); + + jsonw_name(wr, "empty"); + jsonw_start_array(wr); + jsonw_end_array(wr); + + jsonw_name(wr, "NIL"); + jsonw_start_object(wr); + jsonw_end_object(wr); + + jsonw_null_field(wr, "my_null"); + + jsonw_name(wr, "special chars"); + jsonw_start_array(wr); + jsonw_string_field(wr, "slash", "/"); + jsonw_string_field(wr, "newline", "\n"); + jsonw_string_field(wr, "tab", "\t"); + jsonw_string_field(wr, "ff", "\f"); + jsonw_string_field(wr, "quote", "\""); + jsonw_string_field(wr, "tick", "\'"); + jsonw_string_field(wr, "backslash", "\\"); + jsonw_end_array(wr); + + jsonw_end_object(wr); + + jsonw_end_object(wr); + jsonw_destroy(&wr); + return 0; +} + +#endif -- cgit v1.2.3 From f05e2c32f715985f54265b1e237b5cce1b576c71 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Mon, 23 Oct 2017 09:24:10 -0700 Subject: tools: bpftool: add JSON output for `bpftool prog dump xlated *` command Add a new printing function to dump translated eBPF instructions as JSON. As for plain output, opcodes are printed only on request (when `opcodes` is provided on the command line). The disassembled output is generated by the same code that is used by the kernel verifier. Example output: $ bpftool --json --pretty prog dump xlated id 1 [{ "disasm": "(bf) r6 = r1" },{ "disasm": "(61) r7 = *(u32 *)(r6 +16)" },{ "disasm": "(95) exit" } ] $ bpftool --json --pretty prog dump xlated id 1 opcodes [{ "disasm": "(bf) r6 = r1", "opcodes": { "code": "0xbf", "src_reg": "0x1", "dst_reg": "0x6", "off": ["0x00","0x00" ], "imm": ["0x00","0x00","0x00","0x00" ] } },{ "disasm": "(61) r7 = *(u32 *)(r6 +16)", "opcodes": { "code": "0x61", "src_reg": "0x6", "dst_reg": "0x7", "off": ["0x10","0x00" ], "imm": ["0x00","0x00","0x00","0x00" ] } },{ "disasm": "(95) exit", "opcodes": { "code": "0x95", "src_reg": "0x0", "dst_reg": "0x0", "off": ["0x00","0x00" ], "imm": ["0x00","0x00","0x00","0x00" ] } } ] Signed-off-by: Quentin Monnet Acked-by: Daniel Borkmann Signed-off-by: David S. Miller --- tools/bpf/bpftool/common.c | 10 ++++++ tools/bpf/bpftool/json_writer.c | 8 +++++ tools/bpf/bpftool/json_writer.h | 2 ++ tools/bpf/bpftool/main.h | 1 + tools/bpf/bpftool/prog.c | 70 +++++++++++++++++++++++++++++++++++++++-- 5 files changed, 89 insertions(+), 2 deletions(-) (limited to 'tools/bpf/bpftool/json_writer.c') diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c index df8396a0c400..e7a756b8ee21 100644 --- a/tools/bpf/bpftool/common.c +++ b/tools/bpf/bpftool/common.c @@ -214,3 +214,13 @@ char *get_fdinfo(int fd, const char *key) fclose(fdi); return NULL; } + +void print_hex_data_json(uint8_t *data, size_t len) +{ + unsigned int i; + + jsonw_start_array(json_wtr); + for (i = 0; i < len; i++) + jsonw_printf(json_wtr, "\"0x%02hhx\"", data[i]); + jsonw_end_array(json_wtr); +} diff --git a/tools/bpf/bpftool/json_writer.c b/tools/bpf/bpftool/json_writer.c index 6b77d288cce2..c6eef76322ae 100644 --- a/tools/bpf/bpftool/json_writer.c +++ b/tools/bpf/bpftool/json_writer.c @@ -156,6 +156,14 @@ void jsonw_name(json_writer_t *self, const char *name) putc(' ', self->out); } +void jsonw_vprintf_enquote(json_writer_t *self, const char *fmt, va_list ap) +{ + jsonw_eor(self); + putc('"', self->out); + vfprintf(self->out, fmt, ap); + putc('"', self->out); +} + void jsonw_printf(json_writer_t *self, const char *fmt, ...) { va_list ap; diff --git a/tools/bpf/bpftool/json_writer.h b/tools/bpf/bpftool/json_writer.h index 1516aafba59d..0fa2fb1b6351 100644 --- a/tools/bpf/bpftool/json_writer.h +++ b/tools/bpf/bpftool/json_writer.h @@ -17,6 +17,7 @@ #include #include +#include /* Opaque class structure */ typedef struct json_writer json_writer_t; @@ -33,6 +34,7 @@ void jsonw_pretty(json_writer_t *self, bool on); void jsonw_name(json_writer_t *self, const char *name); /* Add value */ +void jsonw_vprintf_enquote(json_writer_t *self, const char *fmt, va_list ap); void jsonw_printf(json_writer_t *self, const char *fmt, ...); void jsonw_string(json_writer_t *self, const char *value); void jsonw_bool(json_writer_t *self, bool value); diff --git a/tools/bpf/bpftool/main.h b/tools/bpf/bpftool/main.h index 15927fc9fb31..693fc9710be1 100644 --- a/tools/bpf/bpftool/main.h +++ b/tools/bpf/bpftool/main.h @@ -95,5 +95,6 @@ int do_map(int argc, char **arg); int prog_parse_fd(int *argc, char ***argv); void disasm_print_insn(unsigned char *image, ssize_t len, int opcodes); +void print_hex_data_json(uint8_t *data, size_t len); #endif diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index f373f2baef5a..43e49799a624 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -385,7 +385,7 @@ static void print_insn(struct bpf_verifier_env *env, const char *fmt, ...) va_end(args); } -static void dump_xlated(void *buf, unsigned int len, bool opcodes) +static void dump_xlated_plain(void *buf, unsigned int len, bool opcodes) { struct bpf_insn *insn = buf; bool double_insn = false; @@ -414,6 +414,69 @@ static void dump_xlated(void *buf, unsigned int len, bool opcodes) } } +static void print_insn_json(struct bpf_verifier_env *env, const char *fmt, ...) +{ + unsigned int l = strlen(fmt); + char chomped_fmt[l]; + va_list args; + + va_start(args, fmt); + if (l > 0) { + strncpy(chomped_fmt, fmt, l - 1); + chomped_fmt[l - 1] = '\0'; + } + jsonw_vprintf_enquote(json_wtr, chomped_fmt, args); + va_end(args); +} + +static void dump_xlated_json(void *buf, unsigned int len, bool opcodes) +{ + struct bpf_insn *insn = buf; + bool double_insn = false; + unsigned int i; + + jsonw_start_array(json_wtr); + for (i = 0; i < len / sizeof(*insn); i++) { + if (double_insn) { + double_insn = false; + continue; + } + double_insn = insn[i].code == (BPF_LD | BPF_IMM | BPF_DW); + + jsonw_start_object(json_wtr); + jsonw_name(json_wtr, "disasm"); + print_bpf_insn(print_insn_json, NULL, insn + i, true); + + if (opcodes) { + jsonw_name(json_wtr, "opcodes"); + jsonw_start_object(json_wtr); + + jsonw_name(json_wtr, "code"); + jsonw_printf(json_wtr, "\"0x%02hhx\"", insn[i].code); + + jsonw_name(json_wtr, "src_reg"); + jsonw_printf(json_wtr, "\"0x%hhx\"", insn[i].src_reg); + + jsonw_name(json_wtr, "dst_reg"); + jsonw_printf(json_wtr, "\"0x%hhx\"", insn[i].dst_reg); + + jsonw_name(json_wtr, "off"); + print_hex_data_json((uint8_t *)(&insn[i].off), 2); + + jsonw_name(json_wtr, "imm"); + if (double_insn && i < len - 1) + print_hex_data_json((uint8_t *)(&insn[i].imm), + 12); + else + print_hex_data_json((uint8_t *)(&insn[i].imm), + 4); + jsonw_end_object(json_wtr); + } + jsonw_end_object(json_wtr); + } + jsonw_end_array(json_wtr); +} + static int do_dump(int argc, char **argv) { struct bpf_prog_info info = {}; @@ -523,7 +586,10 @@ static int do_dump(int argc, char **argv) if (member_len == &info.jited_prog_len) disasm_print_insn(buf, *member_len, opcodes); else - dump_xlated(buf, *member_len, opcodes); + if (json_output) + dump_xlated_json(buf, *member_len, opcodes); + else + dump_xlated_plain(buf, *member_len, opcodes); } free(buf); -- cgit v1.2.3