function.c

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// SPDX-FileCopyrightText: 2019 pancake <pancake@nopcode.org>
// SPDX-FileCopyrightText: 2019 thestr4ng3r <info@florianmaerkl.de>
// SPDX-License-Identifier: LGPL-3.0-only
 
#include <rz_analysis.h>
 
static bool get_functions_block_cb(RzAnalysisBlock *block, void *user) {
    RzList *list = user;
    RzListIter *iter;
    RzAnalysisFunction *fcn;
    rz_list_foreach (block->fcns, iter, fcn) {
        if (rz_list_contains(list, fcn)) {
            continue;
        }
        rz_list_push(list, fcn);
    }
    return true;
}
 
RZ_API RzList /*<RzAnalysisFunction *>*/ *rz_analysis_get_functions_in(RzAnalysis *analysis, ut64 addr) {
    RzList *list = rz_list_new();
    if (!list) {
        return NULL;
    }
    rz_analysis_blocks_foreach_in(analysis, addr, get_functions_block_cb, list);
    return list;
}
 
static bool __fcn_exists(RzAnalysis *analysis, const char *name, ut64 addr) {
    // check if name is already registered
    bool found = false;
    if (addr == UT64_MAX) {
        RZ_LOG_ERROR("Invalid function address (-1) '%s'\n", name);
        return true;
    }
    if (!name) {
        RZ_LOG_INFO("Empty function name, we must auto generate one\n");
        return true;
    }
    RzAnalysisFunction *f = ht_pp_find(analysis->ht_name_fun, name, &found);
    if (f && found) {
        RZ_LOG_ERROR("Invalid function name '%s' at 0x%08" PFMT64x "\n", name, addr);
        return true;
    }
    // check if there's a function already in the given address
    found = false;
    f = ht_up_find(analysis->ht_addr_fun, addr, &found);
    if (f && found) {
        RZ_LOG_ERROR("Function already defined in 0x%08" PFMT64x "\n", addr);
        return true;
    }
    return false;
}
 
RZ_IPI void rz_analysis_var_free(RzAnalysisVar *av);
 
static void inst_vars_kv_free(HtUPKv *kv) {
    rz_pvector_free(kv->value);
}
 
static void labels_kv_free(HtUPKv *kv) {
    free(kv->value);
}
 
static void label_addrs_kv_free(HtPPKv *kv) {
    free(kv->key);
    free(kv->value);
}
 
RZ_API RzAnalysisFunction *rz_analysis_function_new(RzAnalysis *analysis) {
    RzAnalysisFunction *fcn = RZ_NEW0(RzAnalysisFunction);
    if (!fcn) {
        return NULL;
    }
    fcn->analysis = analysis;
    fcn->addr = UT64_MAX;
    fcn->cc = rz_str_constpool_get(&analysis->constpool, rz_analysis_cc_default(analysis));
    fcn->bits = analysis->bits;
    fcn->bbs = rz_list_new();
    fcn->diff = rz_analysis_diff_new();
    fcn->has_changed = true;
    fcn->bp_frame = true;
    fcn->is_noreturn = false;
    fcn->meta._min = UT64_MAX;
    rz_pvector_init(&fcn->vars, NULL);
    fcn->inst_vars = ht_up_new(NULL, inst_vars_kv_free, NULL);
    fcn->labels = ht_up_new(NULL, labels_kv_free, NULL);
    fcn->label_addrs = ht_pp_new(NULL, label_addrs_kv_free, NULL);
    return fcn;
}
 
RZ_API void rz_analysis_function_free(void *_fcn) {
    RzAnalysisFunction *fcn = _fcn;
    if (!_fcn) {
        return;
    }
 
    RzAnalysisBlock *block;
    RzListIter *iter;
    rz_list_foreach (fcn->bbs, iter, block) {
        rz_list_delete_data(block->fcns, fcn);
        rz_analysis_block_unref(block);
    }
    rz_list_free(fcn->bbs);
 
    RzAnalysis *analysis = fcn->analysis;
    if (ht_up_find(analysis->ht_addr_fun, fcn->addr, NULL) == _fcn) {
        ht_up_delete(analysis->ht_addr_fun, fcn->addr);
    }
    if (ht_pp_find(analysis->ht_name_fun, fcn->name, NULL) == _fcn) {
        ht_pp_delete(analysis->ht_name_fun, fcn->name);
    }
 
    ht_up_free(fcn->inst_vars);
    fcn->inst_vars = NULL;
    rz_analysis_function_delete_all_vars(fcn);
 
    ht_up_free(fcn->labels);
    ht_pp_free(fcn->label_addrs);
 
    free(fcn->name);
    fcn->bbs = NULL;
    free(fcn->fingerprint);
    rz_analysis_diff_free(fcn->diff);
    rz_list_free(fcn->imports);
    free(fcn);
}
 
RZ_API bool rz_analysis_add_function(RzAnalysis *analysis, RzAnalysisFunction *fcn) {
    if (__fcn_exists(analysis, fcn->name, fcn->addr)) {
        return false;
    }
    if (analysis->cb.on_fcn_new) {
        analysis->cb.on_fcn_new(analysis, analysis->core, fcn);
    }
    if (analysis->flg_fcn_set) {
        analysis->flg_fcn_set(analysis->flb.f, fcn->name, fcn->addr, rz_analysis_function_size_from_entry(fcn));
    }
    fcn->is_noreturn = rz_analysis_noreturn_at_addr(analysis, fcn->addr);
    rz_list_append(analysis->fcns, fcn);
    ht_pp_insert(analysis->ht_name_fun, fcn->name, fcn);
    ht_up_insert(analysis->ht_addr_fun, fcn->addr, fcn);
    return true;
}
 
RZ_API RzAnalysisFunction *rz_analysis_create_function(RzAnalysis *analysis, const char *name, ut64 addr, int type, RzAnalysisDiff *diff) {
    RzAnalysisFunction *fcn = rz_analysis_function_new(analysis);
    if (!fcn) {
        return NULL;
    }
    fcn->addr = addr;
    fcn->type = type;
    fcn->cc = rz_str_constpool_get(&analysis->constpool, rz_analysis_cc_default(analysis));
    fcn->bits = analysis->bits;
    if (name) {
        free(fcn->name);
        fcn->name = strdup(name);
    } else {
        const char *fcnprefix = analysis->coreb.cfgGet ? analysis->coreb.cfgGet(analysis->coreb.core, "analysis.fcnprefix") : NULL;
        if (!fcnprefix) {
            fcnprefix = "fcn";
        }
        fcn->name = rz_str_newf("%s.%08" PFMT64x, fcnprefix, fcn->addr);
    }
    if (diff) {
        fcn->diff->type = diff->type;
        fcn->diff->addr = diff->addr;
        RZ_FREE(fcn->diff->name);
        if (diff->name) {
            fcn->diff->name = strdup(diff->name);
        }
    }
    if (!rz_analysis_add_function(analysis, fcn)) {
        rz_analysis_function_free(fcn);
        return NULL;
    }
    return fcn;
}
 
RZ_API bool rz_analysis_function_delete(RzAnalysisFunction *fcn) {
    return rz_list_delete_data(fcn->analysis->fcns, fcn);
}
 
RZ_API RzAnalysisFunction *rz_analysis_get_function_at(RzAnalysis *analysis, ut64 addr) {
    bool found = false;
    RzAnalysisFunction *f = ht_up_find(analysis->ht_addr_fun, addr, &found);
    if (f && found) {
        return f;
    }
    return NULL;
}
 
typedef struct {
    HtUP *inst_vars_new;
    st64 delta;
} InstVarsRelocateCtx;
 
static bool inst_vars_relocate_cb(void *user, const ut64 k, const void *v) {
    InstVarsRelocateCtx *ctx = user;
    ht_up_insert(ctx->inst_vars_new, k - ctx->delta, (void *)v);
    return true;
}
 
RZ_API bool rz_analysis_function_relocate(RzAnalysisFunction *fcn, ut64 addr) {
    if (fcn->addr == addr) {
        return true;
    }
    if (rz_analysis_get_function_at(fcn->analysis, addr)) {
        return false;
    }
    ht_up_delete(fcn->analysis->ht_addr_fun, fcn->addr);
 
    // relocate the var accesses (their addrs are relative to the function addr)
    st64 delta = (st64)addr - (st64)fcn->addr;
    void **it;
    rz_pvector_foreach (&fcn->vars, it) {
        RzAnalysisVar *var = *it;
        RzAnalysisVarAccess *acc;
        rz_vector_foreach(&var->accesses, acc) {
            acc->offset -= delta;
        }
    }
    InstVarsRelocateCtx ctx = {
        .inst_vars_new = ht_up_new(NULL, inst_vars_kv_free, NULL),
        .delta = delta
    };
    if (ctx.inst_vars_new) {
        ht_up_foreach(fcn->inst_vars, inst_vars_relocate_cb, &ctx);
        // Do not free the elements of the Ht, because they were moved to ctx.inst_vars_new
        fcn->inst_vars->opt.freefn = NULL;
        ht_up_free(fcn->inst_vars);
        fcn->inst_vars = ctx.inst_vars_new;
    }
 
    fcn->addr = addr;
    ht_up_insert(fcn->analysis->ht_addr_fun, addr, fcn);
    return true;
}
 
RZ_API bool rz_analysis_function_rename(RzAnalysisFunction *fcn, const char *name) {
    RzAnalysis *analysis = fcn->analysis;
    RzAnalysisFunction *existing = ht_pp_find(analysis->ht_name_fun, name, NULL);
    if (existing) {
        if (existing == fcn) {
            // fcn->name == name, nothing to do
            return true;
        }
        return false;
    }
    char *newname = strdup(name);
    if (!newname) {
        return false;
    }
    bool in_tree = ht_pp_delete(analysis->ht_name_fun, fcn->name);
    free(fcn->name);
    fcn->name = newname;
    if (in_tree) {
        // only re-insert if it really was in the tree before
        ht_pp_insert(analysis->ht_name_fun, fcn->name, fcn);
    }
    return true;
}
 
RZ_API void rz_analysis_function_add_block(RzAnalysisFunction *fcn, RzAnalysisBlock *bb) {
    if (rz_list_contains(bb->fcns, fcn)) {
        return;
    }
    rz_list_append(bb->fcns, fcn); // associate the given fcn with this bb
    rz_analysis_block_ref(bb);
    rz_list_append(fcn->bbs, bb);
 
    if (fcn->meta._min != UT64_MAX) {
        if (bb->addr + bb->size > fcn->meta._max) {
            fcn->meta._max = bb->addr + bb->size;
        }
        if (bb->addr < fcn->meta._min) {
            fcn->meta._min = bb->addr;
        }
    }
 
    if (fcn->analysis->cb.on_fcn_bb_new) {
        fcn->analysis->cb.on_fcn_bb_new(fcn->analysis, fcn->analysis->core, fcn, bb);
    }
}
 
RZ_API void rz_analysis_function_remove_block(RzAnalysisFunction *fcn, RzAnalysisBlock *bb) {
    rz_list_delete_data(bb->fcns, fcn);
 
    if (fcn->meta._min != UT64_MAX && (fcn->meta._min == bb->addr || fcn->meta._max == bb->addr + bb->size)) {
        // If a block is removed at the beginning or end, updating min/max is not trivial anymore, just invalidate
        fcn->meta._min = UT64_MAX;
    }
 
    rz_list_delete_data(fcn->bbs, bb);
    rz_analysis_block_unref(bb);
}
 
static void ensure_fcn_range(RzAnalysisFunction *fcn) {
    if (fcn->meta._min != UT64_MAX) { // recalculate only if invalid
        return;
    }
    ut64 minval = UT64_MAX;
    ut64 maxval = UT64_MIN;
    RzAnalysisBlock *block;
    RzListIter *iter;
    rz_list_foreach (fcn->bbs, iter, block) {
        if (block->addr < minval) {
            minval = block->addr;
        }
        if (block->addr + block->size > maxval) {
            maxval = block->addr + block->size;
        }
    }
    fcn->meta._min = minval;
    fcn->meta._max = minval == UT64_MAX ? UT64_MAX : maxval;
}
 
RZ_API ut64 rz_analysis_function_linear_size(RzAnalysisFunction *fcn) {
    ensure_fcn_range(fcn);
    return fcn->meta._max - fcn->meta._min;
}
 
RZ_API ut64 rz_analysis_function_min_addr(RzAnalysisFunction *fcn) {
    ensure_fcn_range(fcn);
    return fcn->meta._min;
}
 
RZ_API ut64 rz_analysis_function_max_addr(RzAnalysisFunction *fcn) {
    ensure_fcn_range(fcn);
    return fcn->meta._max;
}
 
RZ_API ut64 rz_analysis_function_size_from_entry(RzAnalysisFunction *fcn) {
    ensure_fcn_range(fcn);
    return fcn->meta._min == UT64_MAX ? 0 : fcn->meta._max - fcn->addr;
}
 
RZ_API ut64 rz_analysis_function_realsize(const RzAnalysisFunction *fcn) {
    RzListIter *iter;
    RzAnalysisBlock *bb;
    ut64 sz = 0;
    if (!sz) {
        rz_list_foreach (fcn->bbs, iter, bb) {
            sz += bb->size;
        }
    }
    return sz;
}
 
static bool fcn_in_cb(RzAnalysisBlock *block, void *user) {
    RzListIter *iter;
    RzAnalysisFunction *fcn;
    rz_list_foreach (block->fcns, iter, fcn) {
        if (fcn == user) {
            return false;
        }
    }
    return true;
}
 
RZ_API bool rz_analysis_function_contains(RzAnalysisFunction *fcn, ut64 addr) {
    // fcn_in_cb breaks with false if it finds the fcn
    return !rz_analysis_blocks_foreach_in(fcn->analysis, addr, fcn_in_cb, fcn);
}
 
RZ_API bool rz_analysis_function_was_modified(RzAnalysisFunction *fcn) {
    rz_return_val_if_fail(fcn, false);
    RzListIter *it;
    RzAnalysisBlock *bb;
    rz_list_foreach (fcn->bbs, it, bb) {
        if (rz_analysis_block_was_modified(bb)) {
            return true;
        }
    }
    return false;
}
 
RZ_API RZ_BORROW RzList /*<RzAnalysisFunction *>*/ *rz_analysis_function_list(RzAnalysis *analysis) {
    rz_return_val_if_fail(analysis, NULL);
    return analysis->fcns;
}
 
#define MIN_MATCH_LEN 4
 
static RZ_OWN char *function_name_try_guess(RzTypeDB *typedb, RZ_NONNULL char *name) {
    if (strlen(name) < MIN_MATCH_LEN) {
        return NULL;
    }
    if (rz_type_func_exist(typedb, name)) {
        return strdup(name);
    }
    return NULL;
}
 
static inline bool is_auto_named(char *func_name, size_t slen) {
    return slen > 4 && (rz_str_startswith(func_name, "fcn.") || rz_str_startswith(func_name, "loc."));
}
 
static inline bool has_rz_prefixes(char *func_name, int offset, size_t slen) {
    return slen > 4 && (offset + 3 < slen) && func_name[offset + 3] == '.';
}
 
static char *strip_rz_prefixes(char *func_name, size_t slen) {
    // strip rizin prefixes (sym, sym.imp, etc')
    int offset = 0;
    while (has_rz_prefixes(func_name, offset, slen)) {
        offset += 4;
    }
    return func_name + offset;
}
 
static char *strip_common_prefixes_stdlib(char *func_name) {
    // strip common prefixes from standard lib functions
    if (rz_str_startswith(func_name, "__isoc99_")) {
        func_name += 9;
    } else if (rz_str_startswith(func_name, "__libc_") && !strstr(func_name, "_main")) {
        func_name += 7;
    } else if (rz_str_startswith(func_name, "__GI_")) {
        func_name += 5;
    }
    return func_name;
}
 
static char *strip_dll_prefix(char *func_name) {
    char *tmp = strstr(func_name, "dll_");
    if (tmp) {
        return tmp + 3;
    }
    return func_name;
}
 
static void clean_function_name(char *func_name) {
    char *last = (char *)rz_str_lchr(func_name, '_');
    if (!last || !rz_str_isnumber(last + 1)) {
        return;
    }
    *last = '\0';
}
 
RZ_API bool rz_analysis_function_is_autonamed(RZ_NONNULL char *name) {
    size_t len = strlen(name);
    return (len >= MIN_MATCH_LEN) && (is_auto_named(name, len) || has_rz_prefixes(name, 0, len));
}
 
RZ_API RZ_OWN char *rz_analysis_function_name_guess(RzTypeDB *typedb, RZ_NONNULL char *name) {
    rz_return_val_if_fail(typedb && name, NULL);
    char *str = name;
    char *result = NULL;
 
    size_t slen = strlen(str);
    if (slen < MIN_MATCH_LEN || is_auto_named(str, slen)) {
        return NULL;
    }
 
    str = strip_rz_prefixes(str, slen);
    str = strip_common_prefixes_stdlib(str);
    str = strip_dll_prefix(str);
 
    if ((result = function_name_try_guess(typedb, str))) {
        return result;
    }
 
    str = strdup(str);
    clean_function_name(str);
 
    if (*str == '_' && (result = function_name_try_guess(typedb, str + 1))) {
        free(str);
        return result;
    }
 
    free(str);
    return result;
}