root/tools/testing/selftests/bpf/prog_tests/snprintf.c
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2021 Google LLC. */

#include <test_progs.h>
#include "test_snprintf.skel.h"
#include "test_snprintf_single.skel.h"

#define EXP_NUM_OUT  "-8 9 96 -424242 1337 DABBAD00"
#define EXP_NUM_RET  sizeof(EXP_NUM_OUT)

#define EXP_IP_OUT   "127.000.000.001 0000:0000:0000:0000:0000:0000:0000:0001"
#define EXP_IP_RET   sizeof(EXP_IP_OUT)

/* The third specifier, %pB, depends on compiler inlining so don't check it */
#define EXP_SYM_OUT  "schedule schedule+0x0/"
#define MIN_SYM_RET  sizeof(EXP_SYM_OUT)

/* The third specifier, %p, is a hashed pointer which changes on every reboot */
#define EXP_ADDR_OUT "0000000000000000 ffff00000add4e55 "
#define EXP_ADDR_RET sizeof(EXP_ADDR_OUT "unknownhashedptr")

#define EXP_STR_OUT  "str1         a  b c      d e longstr"
#define EXP_STR_RET  sizeof(EXP_STR_OUT)

#define EXP_OVER_OUT "%over"
#define EXP_OVER_RET 10

#define EXP_PAD_OUT "    4 000"
#define EXP_PAD_RET 900007

#define EXP_NO_ARG_OUT "simple case"
#define EXP_NO_ARG_RET 12

#define EXP_NO_BUF_RET 29

static void test_snprintf_positive(void)
{
        char exp_addr_out[] = EXP_ADDR_OUT;
        char exp_sym_out[]  = EXP_SYM_OUT;
        struct test_snprintf *skel;

        skel = test_snprintf__open_and_load();
        if (!ASSERT_OK_PTR(skel, "skel_open"))
                return;

        skel->bss->pid = getpid();

        if (!ASSERT_OK(test_snprintf__attach(skel), "skel_attach"))
                goto cleanup;

        /* trigger tracepoint */
        usleep(1);

        ASSERT_STREQ(skel->bss->num_out, EXP_NUM_OUT, "num_out");
        ASSERT_EQ(skel->bss->num_ret, EXP_NUM_RET, "num_ret");

        ASSERT_STREQ(skel->bss->ip_out, EXP_IP_OUT, "ip_out");
        ASSERT_EQ(skel->bss->ip_ret, EXP_IP_RET, "ip_ret");

        ASSERT_OK(memcmp(skel->bss->sym_out, exp_sym_out,
                         sizeof(exp_sym_out) - 1), "sym_out");
        ASSERT_LT(MIN_SYM_RET, skel->bss->sym_ret, "sym_ret");

        ASSERT_OK(memcmp(skel->bss->addr_out, exp_addr_out,
                         sizeof(exp_addr_out) - 1), "addr_out");
        ASSERT_EQ(skel->bss->addr_ret, EXP_ADDR_RET, "addr_ret");

        ASSERT_STREQ(skel->bss->str_out, EXP_STR_OUT, "str_out");
        ASSERT_EQ(skel->bss->str_ret, EXP_STR_RET, "str_ret");

        ASSERT_STREQ(skel->bss->over_out, EXP_OVER_OUT, "over_out");
        ASSERT_EQ(skel->bss->over_ret, EXP_OVER_RET, "over_ret");

        ASSERT_STREQ(skel->bss->pad_out, EXP_PAD_OUT, "pad_out");
        ASSERT_EQ(skel->bss->pad_ret, EXP_PAD_RET, "pad_ret");

        ASSERT_STREQ(skel->bss->noarg_out, EXP_NO_ARG_OUT, "no_arg_out");
        ASSERT_EQ(skel->bss->noarg_ret, EXP_NO_ARG_RET, "no_arg_ret");

        ASSERT_EQ(skel->bss->nobuf_ret, EXP_NO_BUF_RET, "no_buf_ret");

cleanup:
        test_snprintf__destroy(skel);
}

/* Loads an eBPF object calling bpf_snprintf with up to 10 characters of fmt */
static int load_single_snprintf(char *fmt)
{
        struct test_snprintf_single *skel;
        int ret;

        skel = test_snprintf_single__open();
        if (!skel)
                return -EINVAL;

        memcpy(skel->rodata->fmt, fmt, MIN(strlen(fmt) + 1, 10));

        ret = test_snprintf_single__load(skel);
        test_snprintf_single__destroy(skel);

        return ret;
}

static void test_snprintf_negative(void)
{
        ASSERT_OK(load_single_snprintf("valid %d"), "valid usage");

        ASSERT_ERR(load_single_snprintf("0123456789"), "no terminating zero");
        ASSERT_ERR(load_single_snprintf("%d %d"), "too many specifiers");
        ASSERT_ERR(load_single_snprintf("%pi5"), "invalid specifier 1");
        ASSERT_ERR(load_single_snprintf("%a"), "invalid specifier 2");
        ASSERT_ERR(load_single_snprintf("%"), "invalid specifier 3");
        ASSERT_ERR(load_single_snprintf("%12345678"), "invalid specifier 4");
        ASSERT_ERR(load_single_snprintf("%--------"), "invalid specifier 5");
        ASSERT_ERR(load_single_snprintf("%lc"), "invalid specifier 6");
        ASSERT_ERR(load_single_snprintf("%llc"), "invalid specifier 7");
        ASSERT_ERR(load_single_snprintf("\x80"), "non ascii character");
        ASSERT_ERR(load_single_snprintf("\x1"), "non printable character");
        ASSERT_ERR(load_single_snprintf("%p%"), "invalid specifier 8");
        ASSERT_ERR(load_single_snprintf("%s%"), "invalid specifier 9");
}

void test_snprintf(void)
{
        if (test__start_subtest("snprintf_positive"))
                test_snprintf_positive();
        if (test__start_subtest("snprintf_negative"))
                test_snprintf_negative();
}