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Diffstat (limited to 'src/utils/common/params.c')
| -rw-r--r-- | src/utils/common/params.c | 343 |
1 files changed, 343 insertions, 0 deletions
diff --git a/src/utils/common/params.c b/src/utils/common/params.c new file mode 100644 index 0000000..4db4b9e --- /dev/null +++ b/src/utils/common/params.c @@ -0,0 +1,343 @@ +/* Copyright (C) 2022 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz> + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <https://www.gnu.org/licenses/>. + */ + +#include <arpa/inet.h> +#include <stdio.h> +#include <stdlib.h> +#include <netinet/in.h> +#include <sys/socket.h> + +#ifdef LIBIDN +#include LIBIDN_HEADER +#endif + +#include "utils/common/params.h" +#include "utils/common/msg.h" +#include "utils/common/resolv.h" +#include "utils/common/token.h" +#include "libknot/libknot.h" +#include "contrib/macros.h" +#include "contrib/mempattern.h" +#include "contrib/openbsd/strlcpy.h" +#include "contrib/strtonum.h" + +#define IPV4_REVERSE_DOMAIN "in-addr.arpa." +#define IPV6_REVERSE_DOMAIN "ip6.arpa." + +char *name_from_idn(const char *idn_name) { +#ifdef LIBIDN + char *name = NULL; + + int rc = idna_to_ascii_lz(idn_name, &name, 0); + if (rc != IDNA_SUCCESS) { + ERR("IDNA (%s)", idna_strerror(rc)); + return NULL; + } + + return name; +#endif + return strdup(idn_name); +} + +void name_to_idn(char **name) { +#ifdef LIBIDN + char *idn_name = NULL; + + int rc = idna_to_unicode_8zlz(*name, &idn_name, 0); + if (rc != IDNA_SUCCESS) { + return; + } + + free(*name); + *name = idn_name; +#endif + return; +} + +/*! + * \brief Checks if string is a prefix of reference string. + * + * \param pref Prefix string. + * \param pref_len Prefix length. + * \param str Reference string (must have trailing zero). + * + * \retval -1 \a pref is not a prefix of \a str. + * \retval 0<= number of chars after prefix \a pref in \a str. + */ +static int cmp_prefix(const char *pref, const size_t pref_len, + const char *str) +{ + size_t i = 0; + while (1) { + // Different characters => NOT prefix. + if (pref[i] != str[i]) { + return -1; + } + + i++; + + // Pref IS a prefix of pref. + if (i == pref_len) { + size_t rest = 0; + while (str[i + rest] != '\0') { + rest++; + } + return rest; + // Pref is longer then ref => NOT prefix. + } else if (str[i] == '\0') { + return -1; + } + } +} + +int best_param(const char *str, const size_t str_len, const param_t *tbl, + bool *unique) +{ + if (str == NULL || str_len == 0 || tbl == NULL) { + DBG_NULL; + return KNOT_EINVAL; + } + + int best_pos = -1; + int best_match = INT_MAX; + size_t matches = 0; + for (int i = 0; tbl[i].name != NULL; i++) { + int ret = cmp_prefix(str, str_len, tbl[i].name); + switch (ret) { + case -1: + continue; + case 0: + *unique = true; + return i; + default: + if (ret < best_match) { + best_pos = i; + best_match = ret; + } + matches++; + } + } + + switch (matches) { + case 0: + return KNOT_ENOTSUP; + case 1: + *unique = true; + return best_pos; + default: + *unique = false; + return best_pos; + } +} + +char *get_reverse_name(const char *name) +{ + struct in_addr addr4; + struct in6_addr addr6; + int ret; + char buf[128] = "\0"; + + if (name == NULL) { + DBG_NULL; + return NULL; + } + + // Check name for IPv4 address, IPv6 address or other. + if (inet_pton(AF_INET, name, &addr4) == 1) { + uint32_t num = ntohl(addr4.s_addr); + + // Create IPv4 reverse FQD name. + ret = snprintf(buf, sizeof(buf), "%u.%u.%u.%u.%s", + (num >> 0) & 0xFF, (num >> 8) & 0xFF, + (num >> 16) & 0xFF, (num >> 24) & 0xFF, + IPV4_REVERSE_DOMAIN); + if (ret < 0 || (size_t)ret >= sizeof(buf)) { + return NULL; + } + + return strdup(buf); + } else if (inet_pton(AF_INET6, name, &addr6) == 1) { + char *pos = buf; + size_t len = sizeof(buf); + uint8_t left, right; + + // Create IPv6 reverse name. + for (int i = 15; i >= 0; i--) { + left = ((addr6.s6_addr)[i] & 0xF0) >> 4; + right = (addr6.s6_addr)[i] & 0x0F; + + ret = snprintf(pos, len, "%x.%x.", right, left); + if (ret < 0 || (size_t)ret >= len) { + return NULL; + } + + pos += ret; + len -= ret; + } + + // Add IPv6 reverse domain. + ret = snprintf(pos, len, "%s", IPV6_REVERSE_DOMAIN); + if (ret < 0 || (size_t)ret >= len) { + return NULL; + } + + return strdup(buf); + } else { + return NULL; + } +} + +char *get_fqd_name(const char *name) +{ + char *fqd_name = NULL; + + if (name == NULL) { + DBG_NULL; + return NULL; + } + + size_t name_len = strlen(name); + + // If the name is FQDN, make a copy. + if (name[name_len - 1] == '.') { + fqd_name = strdup(name); + // Else make a copy and append a trailing dot. + } else { + size_t fqd_name_size = name_len + 2; + fqd_name = malloc(fqd_name_size); + if (fqd_name != NULL) { + strlcpy(fqd_name, name, fqd_name_size); + fqd_name[name_len] = '.'; + fqd_name[name_len + 1] = 0; + } + } + + return fqd_name; +} + +int params_parse_class(const char *value, uint16_t *rclass) +{ + if (value == NULL || rclass == NULL) { + DBG_NULL; + return KNOT_EINVAL; + } + + if (knot_rrclass_from_string(value, rclass) == 0) { + return KNOT_EOK; + } else { + return KNOT_EINVAL; + } +} + +int params_parse_type(const char *value, uint16_t *rtype, int64_t *serial, + bool *notify) +{ + if (value == NULL || rtype == NULL || serial == NULL) { + DBG_NULL; + return KNOT_EINVAL; + } + + // Find and parse type name. + size_t param_pos = strcspn(value, "="); + char *type_char = strndup(value, param_pos); + + if (knot_rrtype_from_string(type_char, rtype) != 0) { + size_t cmp_len = MAX(strlen("NOTIFY"), param_pos); + if (strncasecmp(type_char, "NOTIFY", cmp_len) == 0) { + *rtype = KNOT_RRTYPE_SOA; + *notify = true; + } else { + free(type_char); + return KNOT_EINVAL; + } + } else { + *notify = false; + } + + free(type_char); + + // Parse additional parameter. + if (param_pos == strlen(value)) { + // IXFR requires serial parameter. + if (*rtype == KNOT_RRTYPE_IXFR) { + DBG("SOA serial is required for IXFR query"); + return KNOT_EINVAL; + } else { + *serial = -1; + } + } else { + // Additional parameter is accepted for IXFR or NOTIFY. + if (*rtype == KNOT_RRTYPE_IXFR || *notify) { + const char *param_str = value + 1 + param_pos; + char *end; + + // Convert string to serial. + unsigned long long num = strtoull(param_str, &end, 10); + + // Check for bad serial string. + if (end == param_str || *end != '\0' || num > UINT32_MAX) { + DBG("bad SOA serial '%s'", param_str); + return KNOT_EINVAL; + } + + *serial = num; + } else { + DBG("unsupported parameter '%s'", value); + return KNOT_EINVAL; + } + } + + return KNOT_EOK; +} + +int params_parse_server(const char *value, list_t *servers, const char *def_port) +{ + if (value == NULL || servers == NULL) { + DBG_NULL; + return KNOT_EINVAL; + } + + // Add specified nameserver. + srv_info_t *server = parse_nameserver(value, def_port); + if (server == NULL) { + return KNOT_EINVAL; + } + add_tail(servers, (node_t *)server); + + return KNOT_EOK; +} + +int params_parse_wait(const char *value, int32_t *dst) +{ + if (value == NULL || dst == NULL) { + DBG_NULL; + return KNOT_EINVAL; + } + + uint32_t num = 0; + int ret = str_to_u32(value, &num); + if (ret != KNOT_EOK) { + return ret; + } + + if (num < 1 || num > INT32_MAX / 1000) { + num = INT32_MAX / 1000; + } + + *dst = num; + + return KNOT_EOK; +} |