picnoir/Systemd
1
0
Fork 0
Code Issues Pull requests Projects Releases Wiki Activity
Systemd/src/libsystemd-network/network-internal.c
Thomas Haller 072320eab0 dhcp: move filtering of bogus DNS/NTP addresses out of DHCP client 
The DHCP client should not pre-filter addresses beyond what RFC
requires. If a client's user (like networkd) wishes to skip/filter
certain addresses, it's their responsibility.

The point of this is that the DHCP library does not hide/abstract
information that might be relevant for certain users. For example,
NetworkManager exposes DHCP options in its API. When doing that, the
options should be close to the actual lease.

This is related to commit d9ec2e632d
(dhcp4: filter bogus DNS/NTP server addresses silently).
2019-02-18 13:34:22 +01:00

641 lines
18 KiB
C
Raw Blame History

/* SPDX-License-Identifier: LGPL-2.1+ */
#include <arpa/inet.h>
#include <linux/if.h>
#include <netinet/ether.h>
#include "sd-id128.h"
#include "sd-ndisc.h"
#include "alloc-util.h"
#include "condition.h"
#include "conf-parser.h"
#include "device-util.h"
#include "dhcp-lease-internal.h"
#include "ether-addr-util.h"
#include "hexdecoct.h"
#include "log.h"
#include "network-internal.h"
#include "parse-util.h"
#include "siphash24.h"
#include "socket-util.h"
#include "string-util.h"
#include "strv.h"
#include "utf8.h"
#include "util.h"
const char *net_get_name(sd_device *device) {
const char *name, *field;
assert(device);
/* fetch some persistent data unique (on this machine) to this device */
FOREACH_STRING(field, "ID_NET_NAME_ONBOARD", "ID_NET_NAME_SLOT", "ID_NET_NAME_PATH", "ID_NET_NAME_MAC")
if (sd_device_get_property_value(device, field, &name) >= 0)
return name;
return NULL;
}
#define HASH_KEY SD_ID128_MAKE(d3,1e,48,fa,90,fe,4b,4c,9d,af,d5,d7,a1,b1,2e,8a)
int net_get_unique_predictable_data(sd_device *device, uint64_t *result) {
size_t l, sz = 0;
const char *name;
int r;
uint8_t *v;
assert(device);
/* net_get_name() will return one of the device names based on stable information about the
* device. If this is not available, we fall back to using the device name. */
name = net_get_name(device);
if (!name)
(void) sd_device_get_sysname(device, &name);
if (!name)
return log_device_debug_errno(device, SYNTHETIC_ERRNO(ENODATA),
"No stable identifying information found");
log_device_debug(device, "Using \"%s\" as stable identifying information", name);
l = strlen(name);
sz = sizeof(sd_id128_t) + l;
v = newa(uint8_t, sz);
/* Fetch some persistent data unique to this machine */
r = sd_id128_get_machine((sd_id128_t*) v);
if (r < 0)
return r;
memcpy(v + sizeof(sd_id128_t), name, l);
/* Let's hash the machine ID plus the device name. We use
* a fixed, but originally randomly created hash key here. */
*result = htole64(siphash24(v, sz, HASH_KEY.bytes));
return 0;
}
static bool net_condition_test_strv(char * const *raw_patterns,
const char *string) {
if (strv_isempty(raw_patterns))
return true;
/* If the patterns begin with "!", edit it out and negate the test. */
if (raw_patterns[0][0] == '!') {
char **patterns;
size_t i, length;
length = strv_length(raw_patterns) + 1; /* Include the NULL. */
patterns = newa(char*, length);
patterns[0] = raw_patterns[0] + 1; /* Skip the "!". */
for (i = 1; i < length; i++)
patterns[i] = raw_patterns[i];
return !string || !strv_fnmatch(patterns, string, 0);
}
return string && strv_fnmatch(raw_patterns, string, 0);
}
bool net_match_config(Set *match_mac,
char * const *match_paths,
char * const *match_drivers,
char * const *match_types,
char * const *match_names,
Condition *match_host,
Condition *match_virt,
Condition *match_kernel_cmdline,
Condition *match_kernel_version,
Condition *match_arch,
const struct ether_addr *dev_mac,
const char *dev_path,
const char *dev_parent_driver,
const char *dev_driver,
const char *dev_type,
const char *dev_name) {
if (match_host && condition_test(match_host) <= 0)
return false;
if (match_virt && condition_test(match_virt) <= 0)
return false;
if (match_kernel_cmdline && condition_test(match_kernel_cmdline) <= 0)
return false;
if (match_kernel_version && condition_test(match_kernel_version) <= 0)
return false;
if (match_arch && condition_test(match_arch) <= 0)
return false;
if (match_mac && (!dev_mac || !set_contains(match_mac, dev_mac)))
return false;
if (!net_condition_test_strv(match_paths, dev_path))
return false;
if (!net_condition_test_strv(match_drivers, dev_driver))
return false;
if (!net_condition_test_strv(match_types, dev_type))
return false;
if (!net_condition_test_strv(match_names, dev_name))
return false;
return true;
}
int config_parse_net_condition(const char *unit,
const char *filename,
unsigned line,
const char *section,
unsigned section_line,
const char *lvalue,
int ltype,
const char *rvalue,
void *data,
void *userdata) {
ConditionType cond = ltype;
Condition **ret = data;
bool negate;
Condition *c;
_cleanup_free_ char *s = NULL;
assert(filename);
assert(lvalue);
assert(rvalue);
assert(data);
negate = rvalue[0] == '!';
if (negate)
rvalue++;
s = strdup(rvalue);
if (!s)
return log_oom();
c = condition_new(cond, s, false, negate);
if (!c)
return log_oom();
if (*ret)
condition_free(*ret);
*ret = c;
return 0;
}
int config_parse_ifnames(
const char *unit,
const char *filename,
unsigned line,
const char *section,
unsigned section_line,
const char *lvalue,
int ltype,
const char *rvalue,
void *data,
void *userdata) {
char ***sv = data;
int r;
assert(filename);
assert(lvalue);
assert(rvalue);
assert(data);
for (;;) {
_cleanup_free_ char *word = NULL;
r = extract_first_word(&rvalue, &word, NULL, 0);
if (r < 0) {
log_syntax(unit, LOG_ERR, filename, line, 0, "Failed to parse interface name list: %s", rvalue);
return 0;
}
if (r == 0)
break;
if (!ifname_valid(word)) {
log_syntax(unit, LOG_ERR, filename, line, 0, "Interface name is not valid or too long, ignoring assignment: %s", rvalue);
return 0;
}
r = strv_push(sv, word);
if (r < 0)
return log_oom();
word = NULL;
}
return 0;
}
int config_parse_ifalias(const char *unit,
const char *filename,
unsigned line,
const char *section,
unsigned section_line,
const char *lvalue,
int ltype,
const char *rvalue,
void *data,
void *userdata) {
char **s = data;
_cleanup_free_ char *n = NULL;
assert(filename);
assert(lvalue);
assert(rvalue);
assert(data);
n = strdup(rvalue);
if (!n)
return log_oom();
if (!ascii_is_valid(n) || strlen(n) >= IFALIASZ) {
log_syntax(unit, LOG_ERR, filename, line, 0, "Interface alias is not ASCII clean or is too long, ignoring assignment: %s", rvalue);
return 0;
}
if (isempty(n))
*s = mfree(*s);
else
free_and_replace(*s, n);
return 0;
}
int config_parse_hwaddr(const char *unit,
const char *filename,
unsigned line,
const char *section,
unsigned section_line,
const char *lvalue,
int ltype,
const char *rvalue,
void *data,
void *userdata) {
_cleanup_free_ struct ether_addr *n = NULL;
struct ether_addr **hwaddr = data;
int r;
assert(filename);
assert(lvalue);
assert(rvalue);
assert(data);
n = new0(struct ether_addr, 1);
if (!n)
return log_oom();
r = ether_addr_from_string(rvalue, n);
if (r < 0) {
log_syntax(unit, LOG_ERR, filename, line, r, "Not a valid MAC address, ignoring assignment: %s", rvalue);
return 0;
}
free_and_replace(*hwaddr, n);
return 0;
}
int config_parse_hwaddrs(const char *unit,
const char *filename,
unsigned line,
const char *section,
unsigned section_line,
const char *lvalue,
int ltype,
const char *rvalue,
void *data,
void *userdata) {
_cleanup_set_free_free_ Set *s = NULL;
const char *p = rvalue;
Set **hwaddrs = data;
int r;
assert(filename);
assert(lvalue);
assert(rvalue);
assert(data);
if (isempty(rvalue)) {
/* Empty assignment resets the list */
*hwaddrs = set_free_free(*hwaddrs);
return 0;
}
s = set_new(&ether_addr_hash_ops);
if (!s)
return log_oom();
for (;;) {
_cleanup_free_ char *word = NULL;
_cleanup_free_ struct ether_addr *n = NULL;
r = extract_first_word(&p, &word, NULL, 0);
if (r == 0)
break;
if (r == -ENOMEM)
return log_oom();
if (r < 0) {
log_syntax(unit, LOG_WARNING, filename, line, r, "Invalid syntax, ignoring: %s", rvalue);
return 0;
}
n = new(struct ether_addr, 1);
if (!n)
return log_oom();
r = ether_addr_from_string(word, n);
if (r < 0) {
log_syntax(unit, LOG_ERR, filename, line, 0, "Not a valid MAC address, ignoring: %s", word);
continue;
}
r = set_put(s, n);
if (r < 0)
return log_oom();
if (r > 0)
n = NULL; /* avoid cleanup */
}
r = set_ensure_allocated(hwaddrs, &ether_addr_hash_ops);
if (r < 0)
return log_oom();
r = set_move(*hwaddrs, s);
if (r < 0)
return log_oom();
return 0;
}
int config_parse_bridge_port_priority(
const char *unit,
const char *filename,
unsigned line,
const char *section,
unsigned section_line,
const char *lvalue,
int ltype,
const char *rvalue,
void *data,
void *userdata) {
uint16_t i;
int r;
assert(filename);
assert(lvalue);
assert(rvalue);
assert(data);
r = safe_atou16(rvalue, &i);
if (r < 0) {
log_syntax(unit, LOG_ERR, filename, line, r,
"Failed to parse bridge port priority, ignoring: %s", rvalue);
return 0;
}
if (i > LINK_BRIDGE_PORT_PRIORITY_MAX) {
log_syntax(unit, LOG_ERR, filename, line, r,
"Bridge port priority is larger than maximum %u, ignoring: %s", LINK_BRIDGE_PORT_PRIORITY_MAX, rvalue);
return 0;
}
*((uint16_t *)data) = i;
return 0;
}
size_t serialize_in_addrs(FILE *f,
const struct in_addr *addresses,
size_t size,
bool with_leading_space,
bool (*predicate)(const struct in_addr *addr)) {
size_t count;
size_t i;
assert(f);
assert(addresses);
count = 0;
for (i = 0; i < size; i++) {
if (predicate && !predicate(&addresses[i]))
continue;
if (with_leading_space)
fputc(' ', f);
else
with_leading_space = true;
fputs(inet_ntoa(addresses[i]), f);
count++;
}
return count;
}
int deserialize_in_addrs(struct in_addr **ret, const char *string) {
_cleanup_free_ struct in_addr *addresses = NULL;
int size = 0;
assert(ret);
assert(string);
for (;;) {
_cleanup_free_ char *word = NULL;
struct in_addr *new_addresses;
int r;
r = extract_first_word(&string, &word, NULL, 0);
if (r < 0)
return r;
if (r == 0)
break;
new_addresses = reallocarray(addresses, size + 1, sizeof(struct in_addr));
if (!new_addresses)
return -ENOMEM;
else
addresses = new_addresses;
r = inet_pton(AF_INET, word, &(addresses[size]));
if (r <= 0)
continue;
size++;
}
*ret = size > 0 ? TAKE_PTR(addresses) : NULL;
return size;
}
void serialize_in6_addrs(FILE *f, const struct in6_addr *addresses, size_t size) {
unsigned i;
assert(f);
assert(addresses);
assert(size);
for (i = 0; i < size; i++) {
char buffer[INET6_ADDRSTRLEN];
fputs(inet_ntop(AF_INET6, addresses+i, buffer, sizeof(buffer)), f);
if (i < size - 1)
fputc(' ', f);
}
}
int deserialize_in6_addrs(struct in6_addr **ret, const char *string) {
_cleanup_free_ struct in6_addr *addresses = NULL;
int size = 0;
assert(ret);
assert(string);
for (;;) {
_cleanup_free_ char *word = NULL;
struct in6_addr *new_addresses;
int r;
r = extract_first_word(&string, &word, NULL, 0);
if (r < 0)
return r;
if (r == 0)
break;
new_addresses = reallocarray(addresses, size + 1, sizeof(struct in6_addr));
if (!new_addresses)
return -ENOMEM;
else
addresses = new_addresses;
r = inet_pton(AF_INET6, word, &(addresses[size]));
if (r <= 0)
continue;
size++;
}
*ret = TAKE_PTR(addresses);
return size;
}
void serialize_dhcp_routes(FILE *f, const char *key, sd_dhcp_route **routes, size_t size) {
unsigned i;
assert(f);
assert(key);
assert(routes);
assert(size);
fprintf(f, "%s=", key);
for (i = 0; i < size; i++) {
struct in_addr dest, gw;
uint8_t length;
assert_se(sd_dhcp_route_get_destination(routes[i], &dest) >= 0);
assert_se(sd_dhcp_route_get_gateway(routes[i], &gw) >= 0);
assert_se(sd_dhcp_route_get_destination_prefix_length(routes[i], &length) >= 0);
fprintf(f, "%s/%" PRIu8, inet_ntoa(dest), length);
fprintf(f, ",%s%s", inet_ntoa(gw), (i < (size - 1)) ? " ": "");
}
fputs("\n", f);
}
int deserialize_dhcp_routes(struct sd_dhcp_route **ret, size_t *ret_size, size_t *ret_allocated, const char *string) {
_cleanup_free_ struct sd_dhcp_route *routes = NULL;
size_t size = 0, allocated = 0;
assert(ret);
assert(ret_size);
assert(ret_allocated);
assert(string);
/* WORD FORMAT: dst_ip/dst_prefixlen,gw_ip */
for (;;) {
_cleanup_free_ char *word = NULL;
char *tok, *tok_end;
unsigned n;
int r;
r = extract_first_word(&string, &word, NULL, 0);
if (r < 0)
return r;
if (r == 0)
break;
if (!GREEDY_REALLOC(routes, allocated, size + 1))
return -ENOMEM;
tok = word;
/* get the subnet */
tok_end = strchr(tok, '/');
if (!tok_end)
continue;
*tok_end = '\0';
r = inet_aton(tok, &routes[size].dst_addr);
if (r == 0)
continue;
tok = tok_end + 1;
/* get the prefixlen */
tok_end = strchr(tok, ',');
if (!tok_end)
continue;
*tok_end = '\0';
r = safe_atou(tok, &n);
if (r < 0 || n > 32)
continue;
routes[size].dst_prefixlen = (uint8_t) n;
tok = tok_end + 1;
/* get the gateway */
r = inet_aton(tok, &routes[size].gw_addr);
if (r == 0)
continue;
size++;
}
*ret_size = size;
*ret_allocated = allocated;
*ret = TAKE_PTR(routes);
return 0;
}
int serialize_dhcp_option(FILE *f, const char *key, const void *data, size_t size) {
_cleanup_free_ char *hex_buf = NULL;
assert(f);
assert(key);
assert(data);
hex_buf = hexmem(data, size);
if (hex_buf == NULL)
return -ENOMEM;
fprintf(f, "%s=%s\n", key, hex_buf);
return 0;
}
Reference in a new issue View git blame Copy permalink