diff options
| -rw-r--r-- | accel-pppd/iprange.c | 158 |
1 files changed, 63 insertions, 95 deletions
diff --git a/accel-pppd/iprange.c b/accel-pppd/iprange.c index 40c938e..58321bd 100644 --- a/accel-pppd/iprange.c +++ b/accel-pppd/iprange.c @@ -29,12 +29,6 @@ static pthread_mutex_t iprange_lock = PTHREAD_MUTEX_INITIALIZER; static bool conf_disable = false; static LIST_HEAD(client_ranges); -/* Maximum IPv4 address length with CIDR notation but no extra 0, - * e.g. "0xff.0xff.0xff.0xff/32". - */ -#define CIDR_MAXLEN 22 - - static void free_ranges(struct list_head *head) { struct iprange_t *range; @@ -46,115 +40,89 @@ static void free_ranges(struct list_head *head) } } +/* Parse a [client-ip-iprange] configuration entry. + * Ranges can be defined in CIDR notation ("192.0.2.0/24") or by specifying an + * upper bound for the last IPv4 byte, after a '-' character ("192.0.2.0-255"). + * For simplicity, only mention the CIDR notation in error messages. + */ static int parse_iprange(const char *str, struct iprange_t **range) { - char ipstr[CIDR_MAXLEN + 1] = { 0 }; - struct iprange_t *_range; - struct in_addr addr; - char *suffix_str; - uint32_t ipmin; - uint32_t ipmax; - bool is_cidr; - - /* Extra spaces and comments must have already been removed */ - if (strpbrk(str, " \t#")) { - log_error("iprange: impossible to parse range \"%s\":" - " invalid space or comment character found\n", - str); - return -1; - } + struct iprange_t *new_range; + struct in_addr base_addr; + const char *ptr; + uint32_t ip_min; + uint32_t ip_max; + uint8_t suffix; + size_t len; if (!strcmp(str, "disable")) goto disable; - strncpy(ipstr, str, CIDR_MAXLEN + 1); - if (ipstr[CIDR_MAXLEN] != '\0') { - log_error("iprange: impossible to parse range \"%s\":" - " line too long\n", - str); - return -1; - } - - suffix_str = strpbrk(ipstr, "-/"); - if (!suffix_str) { - log_error("iprange: impossible to parse range \"%s\":" - " unrecognised range format\n", - str); - return -1; - } - - is_cidr = *suffix_str == '/'; - *suffix_str = '\0'; - ++suffix_str; - - if (!u_parse_ip4addr(ipstr, &addr)) { - log_error("iprange: impossible to parse range \"%s\":" - " invalid IPv4 address \"%s\"\n", - str, ipstr); - return -1; - } - ipmin = ntohl(addr.s_addr); + ptr = str; - - /* If is_cidr is set, range is given with CIDR notation, - * e.g. "192.0.2.0/24". - * If unset, range is an IP address where the last octet is replaced by - * an octet range, e.g. "192.0.2.0-255". - */ - if (is_cidr) { - long int prefix_len; + /* Try IPv4 CIDR notation first */ + len = u_parse_ip4cidr(ptr, &base_addr, &suffix); + if (len) { + uint32_t addr_hbo; uint32_t mask; - if (u_readlong(&prefix_len, suffix_str, 0, 32)) { - log_error("iprange: impossible to parse range \"%s\":" - " invalid CIDR prefix length \"/%s\"\n", - str, suffix_str); - return -1; - } + /* Cast to uint64_t to avoid undefined 32 bits shift on 32 bits + * integer if 'suffix' is 0. + */ + mask = (uint64_t)0xffffffff << (32 - suffix); + addr_hbo = ntohl(base_addr.s_addr); + ip_min = addr_hbo & mask; + ip_max = addr_hbo | ~mask; + + if (ip_min != addr_hbo) { + struct in_addr min_addr = { .s_addr = htonl(ip_min) }; + char ipbuf[INET_ADDRSTRLEN]; - /* Interpret /0 as disable request */ - if (prefix_len == 0) { - if (ipmin != INADDR_ANY) - log_warn("iprange: %s is equivalent to 0.0.0.0/0 and disables the iprange module\n", - str); - goto disable; + log_warn("iprange: network %s is equivalent to %s/%hhu\n", + str, u_ip4str(&min_addr, ipbuf), suffix); } + goto addrange; + } - mask = INADDR_BROADCAST << (32 - prefix_len); - if (ipmin != (ipmin & mask)) { - char buf[INET_ADDRSTRLEN] = { 0 }; + /* Not an IPv4 CIDR, try the IPv4 range notation */ + len = u_parse_ip4range(ptr, &base_addr, &suffix); + if (len) { + ip_min = ntohl(base_addr.s_addr); + ip_max = (ip_min & 0xffffff00) | suffix; + goto addrange; + } - ipmin &= mask; - addr.s_addr = htonl(ipmin); - log_warn("iprange: first IP of range %s will be %s\n", - str, inet_ntop(AF_INET, &addr, buf, - sizeof(buf))); - } + log_error("iprange: parsing range \"%s\" failed:" + " expecting an IPv4 network prefix in CIDR notation\n", + str); - ipmax = ipmin | ~mask; - } else { - long int max; + return -1; - if (u_readlong(&max, suffix_str, ipmin & 0xff, 255)) { - log_error("iprange: impossible to parse range \"%s\":" - " invalid upper bound \"-%s\"\n", - str, suffix_str); - return -1; - } +addrange: + ptr += len; - ipmax = (ipmin & 0xffffff00) | max; + if (!u_parse_endstr(ptr)) { + log_error("iprange: parsing range \"%s\" failed:" + " unexpected data at \"%s\"\n", + str, ptr); + return -1; } - _range = _malloc(sizeof(*_range)); - if (!_range) { - log_error("iprange: impossible to allocate range \"%s\":" - " memory allocation failed\n", str); + if (ip_min == INADDR_ANY && ip_max == INADDR_BROADCAST) + goto disable; + + new_range = _malloc(sizeof(*new_range)); + if (!new_range) { + log_error("iprange: impossible to load range \"%s\":" + " memory allocation failed\n", + str); return -1; } - _range->begin = ipmin; - _range->end = ipmax; - *range = _range; + new_range->begin = ip_min; + new_range->end = ip_max; + + *range = new_range; return 0; @@ -175,7 +143,7 @@ static bool load_ranges(struct list_head *list, const char *conf_sect) list_for_each_entry(opt, &s->items, entry) { /* Ignore parsing errors, parse_iprange() already logs suitable - * error message. + * error messages. */ if (parse_iprange(opt->name, &r) < 0) continue; 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