Naut/tests/unit/test_bencode.c

#include "naut/bencode.h"
#include "test.h"
#include <string.h>
#include <stdlib.h>

static naut_bc_doc *ok(const char *s) {
    naut_bc_doc *d = NULL;
    naut_err e = naut_bc_parse((const uint8_t *)s, strlen(s), &d);
    if (e != NAUT_OK) { fprintf(stderr, "  unexpected reject: \"%s\" (%s)\n", s, naut_strerror(e)); }
    return e == NAUT_OK ? d : NULL;
}
static int rejects(const char *s, size_t len) {
    naut_bc_doc *d = NULL;
    naut_err e = naut_bc_parse((const uint8_t *)s, len, &d);
    if (e == NAUT_OK) { naut_bc_free(d); return 0; }
    return 1;
}
#define REJECT(s) CHECK(rejects(s, sizeof(s) - 1))

int main(void) {
    /* integers */
    naut_bc_doc *d;
    int64_t iv;
    d = ok("i42e");  CHECK(d && naut_bc_get_int(naut_bc_root(d), &iv) && iv == 42); naut_bc_free(d);
    d = ok("i0e");   CHECK(d && naut_bc_get_int(naut_bc_root(d), &iv) && iv == 0);  naut_bc_free(d);
    d = ok("i-7e");  CHECK(d && naut_bc_get_int(naut_bc_root(d), &iv) && iv == -7); naut_bc_free(d);
    REJECT("ie"); REJECT("i03e"); REJECT("i-0e"); REJECT("i-e"); REJECT("i1 e"); REJECT("i42");

    /* strings (zero-copy + binary-safe) */
    const uint8_t *sp; size_t sn;
    d = ok("4:spam"); CHECK(d && naut_bc_get_str(naut_bc_root(d), &sp, &sn) && sn == 4 && !memcmp(sp,"spam",4));
    /* slice points into the original buffer, not a copy */
    naut_bc_free(d);
    REJECT("4:spa"); REJECT("01:a"); /* leading zero length */

    /* binary string with embedded NUL */
    {
        const char buf[] = "5:a\0b\0c";   /* len prefix "5:" then a \0 b \0 c */
        naut_bc_doc *bd = NULL;
        CHECK(naut_bc_parse((const uint8_t *)buf, 7, &bd) == NAUT_OK);
        CHECK(bd && naut_bc_get_str(naut_bc_root(bd), &sp, &sn) && sn == 5 && sp[1] == 0 && sp[3] == 0);
        naut_bc_free(bd);
    }

    /* list */
    d = ok("l4:spami42ee");
    CHECK(d);
    const naut_bc *l = naut_bc_root(d);
    CHECK(l && l->type == NAUT_BC_LIST && l->v.list.count == 2);
    CHECK(naut_bc_str_eq(naut_bc_list_at(l, 0), "spam"));
    CHECK(naut_bc_get_int(naut_bc_list_at(l, 1), &iv) && iv == 42);
    naut_bc_free(d);

    /* dict + raw span preservation (crucial for info-hash) */
    d = ok("d3:bar4:spam3:fooi42ee");
    const naut_bc *root = naut_bc_root(d);
    CHECK(naut_bc_str_eq(naut_bc_dict_get(root, "bar"), "spam"));
    CHECK(naut_bc_get_int(naut_bc_dict_get(root, "foo"), &iv) && iv == 42);
    const naut_bc *bar = naut_bc_dict_get(root, "bar");
    CHECK(bar->raw_len == 6 && memcmp(bar->raw, "4:spam", 6) == 0);   /* exact encoding */
    CHECK(naut_bc_dict_get(root, "missing") == NULL);
    naut_bc_free(d);

    /* structural rejects */
    REJECT("i1ex");        /* trailing garbage */
    REJECT("d3:bar4:spam"); /* unterminated dict */
    REJECT("l1:a");         /* unterminated list */
    REJECT("di1e1:ae");     /* non-string dict key */
    REJECT("");             /* empty */

    /* depth bomb: 200 nested lists must be rejected, not overflow the stack */
    {
        char bomb[512];
        memset(bomb, 'l', sizeof bomb);
        CHECK(rejects(bomb, sizeof bomb));
    }

    /* encoder round-trips back to an equal parse */
    {
        naut_bc_writer w; naut_bc_w_init(&w);
        naut_bc_w_dict_begin(&w);
        naut_bc_w_cstr(&w, "foo"); naut_bc_w_int(&w, 7);
        naut_bc_w_cstr(&w, "list"); naut_bc_w_list_begin(&w);
        naut_bc_w_cstr(&w, "x"); naut_bc_w_int(&w, -1);
        naut_bc_w_end(&w);
        naut_bc_w_end(&w);
        CHECK(w.err == NAUT_OK);

        naut_bc_doc *rd = NULL;
        CHECK(naut_bc_parse(w.buf, w.len, &rd) == NAUT_OK);
        const naut_bc *r = naut_bc_root(rd);
        CHECK(naut_bc_get_int(naut_bc_dict_get(r, "foo"), &iv) && iv == 7);
        const naut_bc *lst = naut_bc_dict_get(r, "list");
        CHECK(lst && lst->type == NAUT_BC_LIST && lst->v.list.count == 2);
        naut_bc_free(rd);
        naut_bc_w_free(&w);
    }

    TEST_MAIN_END();
}