src/basic/parse-util.c

/***
  This file is part of systemd.

  Copyright 2010 Lennart Poettering

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  systemd is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

#include <errno.h>
#include <inttypes.h>
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <xlocale.h>

#include "alloc-util.h"
#include "extract-word.h"
#include "macro.h"
#include "parse-util.h"
#include "string-util.h"

int parse_boolean(const char *v) {
        assert(v);

        if (streq(v, "1") || strcaseeq(v, "yes") || strcaseeq(v, "y") || strcaseeq(v, "true") || strcaseeq(v, "t") || strcaseeq(v, "on"))
                return 1;
        else if (streq(v, "0") || strcaseeq(v, "no") || strcaseeq(v, "n") || strcaseeq(v, "false") || strcaseeq(v, "f") || strcaseeq(v, "off"))
                return 0;

        return -EINVAL;
}

int parse_pid(const char *s, pid_t* ret_pid) {
        unsigned long ul = 0;
        pid_t pid;
        int r;

        assert(s);
        assert(ret_pid);

        r = safe_atolu(s, &ul);
        if (r < 0)
                return r;

        pid = (pid_t) ul;

        if ((unsigned long) pid != ul)
                return -ERANGE;

        if (pid <= 0)
                return -ERANGE;

        *ret_pid = pid;
        return 0;
}

int parse_mode(const char *s, mode_t *ret) {
        char *x;
        long l;

        assert(s);
        assert(ret);

        s += strspn(s, WHITESPACE);
        if (s[0] == '-')
                return -ERANGE;

        errno = 0;
        l = strtol(s, &x, 8);
        if (errno > 0)
                return -errno;
        if (!x || x == s || *x)
                return -EINVAL;
        if (l < 0 || l  > 07777)
                return -ERANGE;

        *ret = (mode_t) l;
        return 0;
}

int parse_ifindex(const char *s, int *ret) {
        int ifi, r;

        r = safe_atoi(s, &ifi);
        if (r < 0)
                return r;
        if (ifi <= 0)
                return -EINVAL;

        *ret = ifi;
        return 0;
}

int parse_size(const char *t, uint64_t base, uint64_t *size) {

        /* Soo, sometimes we want to parse IEC binary suffixes, and
         * sometimes SI decimal suffixes. This function can parse
         * both. Which one is the right way depends on the
         * context. Wikipedia suggests that SI is customary for
         * hardware metrics and network speeds, while IEC is
         * customary for most data sizes used by software and volatile
         * (RAM) memory. Hence be careful which one you pick!
         *
         * In either case we use just K, M, G as suffix, and not Ki,
         * Mi, Gi or so (as IEC would suggest). That's because that's
         * frickin' ugly. But this means you really need to make sure
         * to document which base you are parsing when you use this
         * call. */

        struct table {
                const char *suffix;
                unsigned long long factor;
        };

        static const struct table iec[] = {
                { "E", 1024ULL*1024ULL*1024ULL*1024ULL*1024ULL*1024ULL },
                { "P", 1024ULL*1024ULL*1024ULL*1024ULL*1024ULL },
                { "T", 1024ULL*1024ULL*1024ULL*1024ULL },
                { "G", 1024ULL*1024ULL*1024ULL },
                { "M", 1024ULL*1024ULL },
                { "K", 1024ULL },
                { "B", 1ULL },
                { "",  1ULL },
        };

        static const struct table si[] = {
                { "E", 1000ULL*1000ULL*1000ULL*1000ULL*1000ULL*1000ULL },
                { "P", 1000ULL*1000ULL*1000ULL*1000ULL*1000ULL },
                { "T", 1000ULL*1000ULL*1000ULL*1000ULL },
                { "G", 1000ULL*1000ULL*1000ULL },
                { "M", 1000ULL*1000ULL },
                { "K", 1000ULL },
                { "B", 1ULL },
                { "",  1ULL },
        };

        const struct table *table;
        const char *p;
        unsigned long long r = 0;
        unsigned n_entries, start_pos = 0;

        assert(t);
        assert(base == 1000 || base == 1024);
        assert(size);

        if (base == 1000) {
                table = si;
                n_entries = ELEMENTSOF(si);
        } else {
                table = iec;
                n_entries = ELEMENTSOF(iec);
        }

        p = t;
        do {
                unsigned long long l, tmp;
                double frac = 0;
                char *e;
                unsigned i;

                p += strspn(p, WHITESPACE);

                errno = 0;
                l = strtoull(p, &e, 10);
                if (errno > 0)
                        return -errno;
                if (e == p)
                        return -EINVAL;
                if (*p == '-')
                        return -ERANGE;

                if (*e == '.') {
                        e++;

                        /* strtoull() itself would accept space/+/- */
                        if (*e >= '0' && *e <= '9') {
                                unsigned long long l2;
                                char *e2;

                                l2 = strtoull(e, &e2, 10);
                                if (errno > 0)
                                        return -errno;

                                /* Ignore failure. E.g. 10.M is valid */
                                frac = l2;
                                for (; e < e2; e++)
                                        frac /= 10;
                        }
                }

                e += strspn(e, WHITESPACE);

                for (i = start_pos; i < n_entries; i++)
                        if (startswith(e, table[i].suffix))
                                break;

                if (i >= n_entries)
                        return -EINVAL;

                if (l + (frac > 0) > ULLONG_MAX / table[i].factor)
                        return -ERANGE;

                tmp = l * table[i].factor + (unsigned long long) (frac * table[i].factor);
                if (tmp > ULLONG_MAX - r)
                        return -ERANGE;

                r += tmp;
                if ((unsigned long long) (uint64_t) r != r)
                        return -ERANGE;

                p = e + strlen(table[i].suffix);

                start_pos = i + 1;

        } while (*p);

        *size = r;

        return 0;
}

int parse_range(const char *t, unsigned *lower, unsigned *upper) {
        _cleanup_free_ char *word = NULL;
        unsigned l, u;
        int r;

        assert(lower);
        assert(upper);

        /* Extract the lower bound. */
        r = extract_first_word(&t, &word, "-", EXTRACT_DONT_COALESCE_SEPARATORS);
        if (r < 0)
                return r;
        if (r == 0)
                return -EINVAL;

        r = safe_atou(word, &l);
        if (r < 0)
                return r;

        /* Check for the upper bound and extract it if needed */
        if (!t)
                /* Single number with no dashes. */
                u = l;
        else if (!*t)
                /* Trailing dash is an error. */
                return -EINVAL;
        else {
                r = safe_atou(t, &u);
                if (r < 0)
                        return r;
        }

        *lower = l;
        *upper = u;
        return 0;
}

char *format_bytes(char *buf, size_t l, uint64_t t) {
        unsigned i;

        /* This only does IEC units so far */

        static const struct {
                const char *suffix;
                uint64_t factor;
        } table[] = {
                { "E", UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024) },
                { "P", UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024) },
                { "T", UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024) },
                { "G", UINT64_C(1024)*UINT64_C(1024)*UINT64_C(1024) },
                { "M", UINT64_C(1024)*UINT64_C(1024) },
                { "K", UINT64_C(1024) },
        };

        if (t == (uint64_t) -1)
                return NULL;

        for (i = 0; i < ELEMENTSOF(table); i++) {

                if (t >= table[i].factor) {
                        snprintf(buf, l,
                                 "%" PRIu64 ".%" PRIu64 "%s",
                                 t / table[i].factor,
                                 ((t*UINT64_C(10)) / table[i].factor) % UINT64_C(10),
                                 table[i].suffix);

                        goto finish;
                }
        }

        snprintf(buf, l, "%" PRIu64 "B", t);

finish:
        buf[l-1] = 0;
        return buf;

}

int safe_atou(const char *s, unsigned *ret_u) {
        char *x = NULL;
        unsigned long l;

        assert(s);
        assert(ret_u);

        /* strtoul() is happy to parse negative values, and silently
         * converts them to unsigned values without generating an
         * error. We want a clean error, hence let's look for the "-"
         * prefix on our own, and generate an error. But let's do so
         * only after strtoul() validated that the string is clean
         * otherwise, so that we return EINVAL preferably over
         * ERANGE. */

        s += strspn(s, WHITESPACE);

        errno = 0;
        l = strtoul(s, &x, 0);
        if (errno > 0)
                return -errno;
        if (!x || x == s || *x)
                return -EINVAL;
        if (s[0] == '-')
                return -ERANGE;
        if ((unsigned long) (unsigned) l != l)
                return -ERANGE;

        *ret_u = (unsigned) l;
        return 0;
}

int safe_atoi(const char *s, int *ret_i) {
        char *x = NULL;
        long l;

        assert(s);
        assert(ret_i);

        errno = 0;
        l = strtol(s, &x, 0);
        if (errno > 0)
                return -errno;
        if (!x || x == s || *x)
                return -EINVAL;
        if ((long) (int) l != l)
                return -ERANGE;

        *ret_i = (int) l;
        return 0;
}

int safe_atollu(const char *s, long long unsigned *ret_llu) {
        char *x = NULL;
        unsigned long long l;

        assert(s);
        assert(ret_llu);

        s += strspn(s, WHITESPACE);

        errno = 0;
        l = strtoull(s, &x, 0);
        if (errno > 0)
                return -errno;
        if (!x || x == s || *x)
                return -EINVAL;
        if (*s == '-')
                return -ERANGE;

        *ret_llu = l;
        return 0;
}

int safe_atolli(const char *s, long long int *ret_lli) {
        char *x = NULL;
        long long l;

        assert(s);
        assert(ret_lli);

        errno = 0;
        l = strtoll(s, &x, 0);
        if (errno > 0)
                return -errno;
        if (!x || x == s || *x)
                return -EINVAL;

        *ret_lli = l;
        return 0;
}

int safe_atou8(const char *s, uint8_t *ret) {
        char *x = NULL;
        unsigned long l;

        assert(s);
        assert(ret);

        s += strspn(s, WHITESPACE);

        errno = 0;
        l = strtoul(s, &x, 0);
        if (errno > 0)
                return -errno;
        if (!x || x == s || *x)
                return -EINVAL;
        if (s[0] == '-')
                return -ERANGE;
        if ((unsigned long) (uint8_t) l != l)
                return -ERANGE;

        *ret = (uint8_t) l;
        return 0;
}

int safe_atou16(const char *s, uint16_t *ret) {
        char *x = NULL;
        unsigned long l;

        assert(s);
        assert(ret);

        s += strspn(s, WHITESPACE);

        errno = 0;
        l = strtoul(s, &x, 0);
        if (errno > 0)
                return -errno;
        if (!x || x == s || *x)
                return -EINVAL;
        if (s[0] == '-')
                return -ERANGE;
        if ((unsigned long) (uint16_t) l != l)
                return -ERANGE;

        *ret = (uint16_t) l;
        return 0;
}

int safe_atoi16(const char *s, int16_t *ret) {
        char *x = NULL;
        long l;

        assert(s);
        assert(ret);

        errno = 0;
        l = strtol(s, &x, 0);
        if (errno > 0)
                return -errno;
        if (!x || x == s || *x)
                return -EINVAL;
        if ((long) (int16_t) l != l)
                return -ERANGE;

        *ret = (int16_t) l;
        return 0;
}

int safe_atod(const char *s, double *ret_d) {
        char *x = NULL;
        double d = 0;
        locale_t loc;

        assert(s);
        assert(ret_d);

        loc = newlocale(LC_NUMERIC_MASK, "C", (locale_t) 0);
        if (loc == (locale_t) 0)
                return -errno;

        errno = 0;
        d = strtod_l(s, &x, loc);
        if (errno > 0) {
                freelocale(loc);
                return -errno;
        }
        if (!x || x == s || *x) {
                freelocale(loc);
                return -EINVAL;
        }

        freelocale(loc);
        *ret_d = (double) d;
        return 0;
}

int parse_fractional_part_u(const char **p, size_t digits, unsigned *res) {
        size_t i;
        unsigned val = 0;
        const char *s;

        s = *p;

        /* accept any number of digits, strtoull is limted to 19 */
        for (i=0; i < digits; i++,s++) {
                if (*s < '0' || *s > '9') {
                        if (i == 0)
                                return -EINVAL;

                        /* too few digits, pad with 0 */
                        for (; i < digits; i++)
                                val *= 10;

                        break;
                }

                val *= 10;
                val += *s - '0';
        }

        /* maybe round up */
        if (*s >= '5' && *s <= '9')
                val++;

        s += strspn(s, DIGITS);

        *p = s;
        *res = val;

        return 0;
}