move alloc_shared to utils

[trinity.git] / tables.c

/*
 * Functions for handling the system call tables.
 */

#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>

#include "arch.h"
#include "arch-syscalls.h"
#include "log.h"
#include "params.h"
#include "syscall.h"
#include "shm.h"
#include "tables.h"
#include "utils.h"      // ARRAY_SIZE

unsigned long syscalls_todo = 0;

bool biarch = FALSE;

int search_syscall_table(const struct syscalltable *table, unsigned int nr_syscalls, const char *arg)
{
        unsigned int i;

        /* search by name */
        for (i = 0; i < nr_syscalls; i++) {
                if (strcmp(arg, table[i].entry->name) == 0) {
                        //debugf("Found %s at %u\n", table[i].entry->name, i);
                        return i;
                }
        }

        return -1;
}

void validate_specific_syscall(const struct syscalltable *table, int call)
{
        struct syscallentry *entry;

        if (call == -1)
                return;

        entry = table[call].entry;

        if (entry->flags & AVOID_SYSCALL)
                output(0, "%s is marked as AVOID. Skipping\n", entry->name);

        if (entry->flags & NI_SYSCALL)
                output(0, "%s is NI_SYSCALL. Skipping\n", entry->name);
}

int validate_specific_syscall_silent(const struct syscalltable *table, int call)
{
        struct syscallentry *entry;

        if (call == -1)
                return FALSE;

        entry = table[call].entry;

        if (entry->flags & AVOID_SYSCALL)
                return FALSE;

        if (entry->flags & NI_SYSCALL)
                return FALSE;

        return TRUE;
}

void activate_syscall_in_table(unsigned int calln, unsigned int *nr_active, const struct syscalltable *table, int *active_syscall)
{
        struct syscallentry *entry = table[calln].entry;

        //Check if the call is activated already, and activate it only if needed
        if (entry->active_number == 0) {
                //Sanity check
                if ((*nr_active + 1) > MAX_NR_SYSCALL) {
                        output(0, "[tables] MAX_NR_SYSCALL needs to be increased. More syscalls than active table can fit.\n");
                        exit(EXIT_FAILURE);
                }

                //save the call no
                active_syscall[*nr_active] = calln + 1;
                (*nr_active) += 1;
                entry->active_number = *nr_active;
        }
}

void deactivate_syscall_in_table(unsigned int calln, unsigned int *nr_active, const struct syscalltable *table, int *active_syscall)
{
        struct syscallentry *entry;

        entry = table[calln].entry;

        //Check if the call is activated already, and deactivate it only if needed
        if ((entry->active_number != 0) && (*nr_active > 0)) {
                unsigned int i;

                for (i = entry->active_number - 1; i < *nr_active - 1; i++) {
                        active_syscall[i] = active_syscall[i + 1];
                        table[active_syscall[i] - 1].entry->active_number = i + 1;
                }
                //The last step is to erase the last item.
                active_syscall[*nr_active - 1] = 0;
                (*nr_active) -= 1;
                entry->active_number = 0;
        }
}

void count_syscalls_enabled(void)
{
        if (biarch == TRUE) {
                output(0, "32-bit syscalls: %d enabled, %d disabled.  "
                        "64-bit syscalls: %d enabled, %d disabled.\n",
                        shm->nr_active_32bit_syscalls, max_nr_32bit_syscalls - shm->nr_active_32bit_syscalls,
                        shm->nr_active_64bit_syscalls, max_nr_64bit_syscalls - shm->nr_active_64bit_syscalls);
        } else {
                output(0, "Enabled %d syscalls. Disabled %d syscalls.\n",
                        shm->nr_active_syscalls, max_nr_syscalls - shm->nr_active_syscalls);
        }
}

void init_syscalls(void)
{
        if (biarch == TRUE)
                init_syscalls_biarch();
        else
                init_syscalls_uniarch();
}

bool no_syscalls_enabled(void)
{
        if (biarch == TRUE) {
                if ((shm->nr_active_32bit_syscalls == 0) && (shm->nr_active_64bit_syscalls == 0))
                        return TRUE;
                else
                        return FALSE;
        }

        /* non-biarch */
        if (shm->nr_active_syscalls == 0)
                return TRUE;
        else
                return FALSE;
}

/* Make sure there's at least one syscall enabled. */
int validate_syscall_tables(void)
{
        if (biarch == TRUE) {
                unsigned int ret;

                ret = validate_syscall_table_32();
                ret |= validate_syscall_table_64();
                return ret;
        }

        /* non-biarch case*/
        if (shm->nr_active_syscalls == 0)
                return FALSE;
        else
                return TRUE;
}

static void check_syscall(struct syscallentry *entry)
{
        /* check that we have a name set. */
#define CHECK(NUMARGS, ARGNUM, ARGTYPE, ARGNAME)                \
        if (entry->num_args > 0) {                              \
                if (entry->num_args > NUMARGS) {                \
                        if (entry->ARGNAME == NULL)  {          \
                                outputerr("arg %d of %s has no name\n", ARGNUM, entry->name);      \
                                exit(EXIT_FAILURE);             \
                        }                                       \
                }                                               \
        }                                                       \

        CHECK(0, 1, arg1type, arg1name);
        CHECK(1, 2, arg2type, arg2name);
        CHECK(2, 3, arg3type, arg3name);
        CHECK(3, 4, arg4type, arg4name);
        CHECK(4, 5, arg5type, arg5name);
        CHECK(5, 6, arg6type, arg6name);

        /* check if we have a type. */
        /* note: not enabled by default, because we haven't annotated everything yet. */
#undef CHECK
#define CHECK(NUMARGS, ARGNUM, ARGTYPE, ARGNAME)                \
        if (entry->num_args > 0) {                              \
                if (entry->num_args > NUMARGS) {                \
                        if (entry->ARGTYPE == ARG_UNDEFINED) {  \
                                outputerr("%s has an undefined argument type for arg1 (%s)!\n", entry->name, entry->ARGNAME);   \
                        }                                       \
                }                                               \
        }                                                       \

/*      CHECK(0, 1, arg1type, arg1name);
        CHECK(1, 2, arg2type, arg2name);
        CHECK(2, 3, arg3type, arg3name);
        CHECK(3, 4, arg4type, arg4name);
        CHECK(4, 5, arg5type, arg5name);
        CHECK(5, 6, arg6type, arg6name);
*/
}

static void sanity_check(const struct syscalltable *table, unsigned int nr)
{
        unsigned int i;

        for (i = 0; i < nr; i++)
                check_syscall(table[i].entry);
}

void sanity_check_tables(void)
{
        if (biarch == TRUE) {
                sanity_check(syscalls_32bit, max_nr_32bit_syscalls);
                sanity_check(syscalls_64bit, max_nr_64bit_syscalls);
                return;
        }

        /* non-biarch case*/
        sanity_check(syscalls, max_nr_syscalls);
}

void mark_all_syscalls_active(void)
{
        outputstd("Marking all syscalls as enabled.\n");

        if (biarch == TRUE)
                mark_all_syscalls_active_biarch();
        else
                mark_all_syscalls_active_uniarch();
}

void check_user_specified_arch(const char *arg, char **arg_name, bool *only_64bit, bool *only_32bit)
{
        //Check if the arch is specified
        char *arg_arch = strstr(arg,",");

        if (arg_arch  != NULL) {
                unsigned long size = 0;

                size = (unsigned long)arg_arch - (unsigned long)arg;
                *arg_name = malloc(size + 1);
                if (*arg_name == NULL)
                        exit(EXIT_FAILURE);
                (*arg_name)[size] = 0;
                memcpy(*arg_name, arg, size);

                //identify architecture
                if ((only_64bit != NULL) && (only_32bit != NULL)) {
                        if ((strcmp(arg_arch + 1, "64") == 0)) {
                                *only_64bit = TRUE;
                                *only_32bit = FALSE;
                        } else if ((strcmp(arg_arch + 1,"32") == 0)) {
                                *only_64bit = FALSE;
                                *only_32bit = TRUE;
                        } else {
                                outputerr("Unknown bit width (%s). Choose 32, or 64.\n", arg);
                                exit(EXIT_FAILURE);
                        }
                }
        } else {
                *arg_name = (char*)arg;//castaway const.
        }
}

void clear_check_user_specified_arch(const char *arg, char **arg_name)
{
        //Release memory only if we have allocated it
        if (((char *)arg) != *arg_name) {
                free(*arg_name);
                *arg_name = NULL;
        }
}

void toggle_syscall(const char *arg, bool state)
{
        int specific_syscall = 0;
        char * arg_name = NULL;

        if (biarch == TRUE) {
                toggle_syscall_biarch(arg, state);
                return;
        }

        /* non-biarch case. */
        check_user_specified_arch(arg, &arg_name, NULL, NULL); //We do not care about arch here, just to get rid of arg flags.

        specific_syscall = search_syscall_table(syscalls, max_nr_syscalls, arg_name);
        if (specific_syscall == -1) {
                outputerr("No idea what syscall (%s) is.\n", arg);
                goto out;
        }

        toggle_syscall_n(specific_syscall, state, arg, arg_name);

out:
        clear_check_user_specified_arch(arg, &arg_name);
}

void deactivate_disabled_syscalls(void)
{
        output(0, "Disabling syscalls marked as disabled by command line options\n");

        if (biarch == TRUE)
                deactivate_disabled_syscalls_biarch();
        else
                deactivate_disabled_syscalls_uniarch();
}

void show_state(unsigned int state)
{
        if (state)
                outputstd("Enabled");
        else
                outputstd("Disabled");
}

void dump_syscall_tables(void)
{
        if (biarch == TRUE)
                dump_syscall_tables_biarch();
        else
                dump_syscall_tables_uniarch();
}

/*
 * This changes the pointers in the table 'from' to be copies in
 * shared mmaps across all children.  We do this so that a child can
 * modify the flags field (adding AVOID for eg) and have other processes see the change.
 */
static struct syscalltable * copy_syscall_table(struct syscalltable *from, unsigned int nr)
{
        unsigned int n;
        struct syscallentry *copy;

        copy = alloc_shared(nr * sizeof(struct syscallentry));
        if (copy == NULL)
                exit(EXIT_FAILURE);

        for (n = 0; n < nr; n++) {
                memcpy(copy + n , from[n].entry, sizeof(struct syscallentry));
                copy[n].number = n;
                copy[n].active_number = 0;
                from[n].entry = &copy[n];
        }
        return from;
}

void select_syscall_tables(void)
{
#ifdef ARCH_IS_BIARCH
        syscalls_64bit = copy_syscall_table(SYSCALLS64, ARRAY_SIZE(SYSCALLS64));
        syscalls_32bit = copy_syscall_table(SYSCALLS32, ARRAY_SIZE(SYSCALLS32));

        max_nr_64bit_syscalls = ARRAY_SIZE(SYSCALLS64);
        max_nr_32bit_syscalls = ARRAY_SIZE(SYSCALLS32);
        biarch = TRUE;
#else
        syscalls = copy_syscall_table(SYSCALLS, ARRAY_SIZE(SYSCALLS));
        max_nr_syscalls = ARRAY_SIZE(SYSCALLS);
#endif
}

int setup_syscall_group(unsigned int group)
{
        if (biarch == TRUE)
                return setup_syscall_group_biarch(group);
        else
                return setup_syscall_group_uniarch(group);
}

const char * print_syscall_name(unsigned int callno, bool is32bit)
{
        const struct syscalltable *table;
        unsigned int max;

        if (biarch == FALSE) {
                max = max_nr_syscalls;
                table = syscalls;
        } else {
                if (is32bit == FALSE) {
                        max = max_nr_64bit_syscalls;
                        table = syscalls_64bit;
                } else {
                        max = max_nr_32bit_syscalls;
                        table = syscalls_32bit;
                }
        }

        if (callno >= max) {
                outputstd("Bogus syscall number in %s (%u)\n", __func__, callno);
                return "invalid-syscall";
        }

        return table[callno].entry->name;
}

void display_enabled_syscalls(void)
{
        if (biarch == TRUE)
                display_enabled_syscalls_biarch();
        else
                display_enabled_syscalls_uniarch();
}

static bool check_for_argtype(const struct syscalltable *table, unsigned int num, unsigned int argtype)
{
        struct syscallentry *entry = table[num].entry;

        unsigned int i;

        for (i = 0; i < entry->num_args; i++) {
                switch (i) {
                case 0: if (entry->arg1type == argtype)
                                return TRUE;
                        break;
                case 1: if (entry->arg2type == argtype)
                                return TRUE;
                        break;
                case 2: if (entry->arg3type == argtype)
                                return TRUE;
                        break;
                case 3: if (entry->arg4type == argtype)
                                return TRUE;
                        break;
                case 4: if (entry->arg5type == argtype)
                                return TRUE;
                        break;
                case 5: if (entry->arg6type == argtype)
                                return TRUE;
                        break;
                }
        }

        return FALSE;
}

/* Consider anything with an ARG_FD or ARG_SOCKADDR a network syscall. */
bool is_syscall_net_related(const struct syscalltable *table, unsigned int num)
{
        if (check_for_argtype(table, num, ARG_FD) == TRUE)
                return TRUE;

        if (check_for_argtype(table, num, ARG_SOCKADDR) == TRUE)
                return TRUE;

        return FALSE;
}

void disable_non_net_syscalls(void)
{
        output(0, "Disabling non networking related syscalls\n");

        if (biarch == TRUE)
                disable_non_net_syscalls_biarch();
        else
                disable_non_net_syscalls_uniarch();

        deactivate_disabled_syscalls();
}

void enable_random_syscalls(void)
{
        unsigned int i;

        if (random_selection_num == 0) {
                outputerr("-r 0 syscalls ? what?\n");
                exit(EXIT_FAILURE);
        }

        if (biarch == TRUE) {
                if ((random_selection_num > max_nr_64bit_syscalls) && do_64_arch) {
                        outputerr("-r val %d out of range (1-%d)\n", random_selection_num, max_nr_64bit_syscalls);
                        exit(EXIT_FAILURE);
                }
        } else {
                if (random_selection_num > max_nr_syscalls) {
                        outputerr("-r val %d out of range (1-%d)\n", random_selection_num, max_nr_syscalls);
                        exit(EXIT_FAILURE);
                }
        }

        outputerr("Enabling %d random syscalls\n", random_selection_num);

        for (i = 0; i < random_selection_num; i++) {
                if (biarch == TRUE)
                        enable_random_syscalls_biarch();
                else
                        enable_random_syscalls_uniarch();
        }
}


/* This is run *after* we've parsed params */
int munge_tables(void)
{
        /* By default, all syscall entries will be disabled.
         * If we didn't pass -c, -x or -r, mark all syscalls active.
         */
        if ((do_specific_syscall == FALSE) && (do_exclude_syscall == FALSE) && (random_selection == FALSE) && (desired_group == GROUP_NONE))
                mark_all_syscalls_active();

        if (desired_group != GROUP_NONE) {
                unsigned int ret;

                ret = setup_syscall_group(desired_group);
                if (ret == FALSE)
                        return FALSE;
        }

        if (random_selection == TRUE)
                enable_random_syscalls();

        /* If we saw a '-x', set all syscalls to enabled, then selectively disable.
         * Unless we've started enabling them already (with -r) (or if we specified a group -g)
         */
        if (do_exclude_syscall == TRUE) {
                if ((random_selection == FALSE) && (desired_group == GROUP_NONE))
                        mark_all_syscalls_active();
                deactivate_disabled_syscalls();
        }

        /* if we passed -n, make sure there's no VM/VFS syscalls enabled. */
        if (no_files == TRUE)
                disable_non_net_syscalls();

        sanity_check_tables();

        count_syscalls_enabled();

        if (verbose == TRUE)
                display_enabled_syscalls();

        if (validate_syscall_tables() == FALSE) {
                outputstd("No syscalls were enabled!\n");
                outputstd("Use 32bit:%d 64bit:%d\n", use_32bit, use_64bit);
                return FALSE;
        }

        return TRUE;
}