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Diffstat (limited to 'src/resolve/resolved-etc-hosts.c')
-rw-r--r--src/resolve/resolved-etc-hosts.c348
1 files changed, 147 insertions, 201 deletions
diff --git a/src/resolve/resolved-etc-hosts.c b/src/resolve/resolved-etc-hosts.c
index 507f68b47f..01cde4acf7 100644
--- a/src/resolve/resolved-etc-hosts.c
+++ b/src/resolve/resolved-etc-hosts.c
@@ -3,8 +3,8 @@
#include "fd-util.h"
#include "fileio.h"
#include "hostname-util.h"
-#include "resolved-etc-hosts.h"
#include "resolved-dns-synthesize.h"
+#include "resolved-etc-hosts.h"
#include "string-util.h"
#include "strv.h"
#include "time-util.h"
@@ -12,103 +12,64 @@
/* Recheck /etc/hosts at most once every 2s */
#define ETC_HOSTS_RECHECK_USEC (2*USEC_PER_SEC)
-typedef struct EtcHostsItem {
- int family;
- union in_addr_union address;
-
- char **names;
-} EtcHostsItem;
-
-typedef struct EtcHostsItemByName {
- char *name;
-
- EtcHostsItem **items;
- size_t n_items, n_allocated;
-} EtcHostsItemByName;
-
-void manager_etc_hosts_flush(Manager *m) {
- EtcHostsItem *item;
- EtcHostsItemByName *bn;
-
- while ((item = set_steal_first(m->etc_hosts_by_address))) {
- strv_free(item->names);
- free(item);
- }
-
- while ((bn = hashmap_steal_first(m->etc_hosts_by_name))) {
- free(bn->name);
- free(bn->items);
- free(bn);
- }
-
- m->etc_hosts_by_address = set_free(m->etc_hosts_by_address);
- m->etc_hosts_by_name = hashmap_free(m->etc_hosts_by_name);
-
- m->etc_hosts_mtime = USEC_INFINITY;
+static inline void etc_hosts_item_free(EtcHostsItem *item) {
+ strv_free(item->names);
+ free(item);
}
-static void etc_hosts_item_hash_func(const void *p, struct siphash *state) {
- const EtcHostsItem *item = p;
-
- siphash24_compress(&item->family, sizeof(item->family), state);
-
- if (item->family == AF_INET)
- siphash24_compress(&item->address.in, sizeof(item->address.in), state);
- else if (item->family == AF_INET6)
- siphash24_compress(&item->address.in6, sizeof(item->address.in6), state);
+static inline void etc_hosts_item_by_name_free(EtcHostsItemByName *item) {
+ free(item->name);
+ free(item->addresses);
+ free(item);
}
-static int etc_hosts_item_compare_func(const void *a, const void *b) {
- const EtcHostsItem *x = a, *y = b;
-
- if (x->family != y->family)
- return x->family - y->family;
-
- if (x->family == AF_INET)
- return memcmp(&x->address.in.s_addr, &y->address.in.s_addr, sizeof(struct in_addr));
-
- if (x->family == AF_INET6)
- return memcmp(&x->address.in6.s6_addr, &y->address.in6.s6_addr, sizeof(struct in6_addr));
-
- return trivial_compare_func(a, b);
+void etc_hosts_free(EtcHosts *hosts) {
+ hosts->by_address = hashmap_free_with_destructor(hosts->by_address, etc_hosts_item_free);
+ hosts->by_name = hashmap_free_with_destructor(hosts->by_name, etc_hosts_item_by_name_free);
+ hosts->no_address = set_free_free(hosts->no_address);
}
-static const struct hash_ops etc_hosts_item_ops = {
- .hash = etc_hosts_item_hash_func,
- .compare = etc_hosts_item_compare_func,
-};
-
-static int add_item(Manager *m, int family, const union in_addr_union *address, char **names) {
+void manager_etc_hosts_flush(Manager *m) {
+ etc_hosts_free(&m->etc_hosts);
+ m->etc_hosts_mtime = USEC_INFINITY;
+}
- EtcHostsItem key = {
- .family = family,
- .address = *address,
- };
+static int parse_line(EtcHosts *hosts, unsigned nr, const char *line) {
+ _cleanup_free_ char *address_str = NULL;
+ struct in_addr_data address = {};
+ bool found = false;
EtcHostsItem *item;
- char **n;
int r;
- assert(m);
- assert(address);
+ assert(hosts);
+ assert(line);
- r = in_addr_is_null(family, address);
+ r = extract_first_word(&line, &address_str, NULL, EXTRACT_RELAX);
if (r < 0)
- return r;
+ return log_error_errno(r, "/etc/hosts:%u: failed to extract address: %m", nr);
+ assert(r > 0); /* We already checked that the line is not empty, so it should contain *something* */
+
+ r = in_addr_ifindex_from_string_auto(address_str, &address.family, &address.address, NULL);
+ if (r < 0) {
+ log_warning_errno(r, "/etc/hosts:%u: address '%s' is invalid, ignoring: %m", nr, address_str);
+ return 0;
+ }
+
+ r = in_addr_is_null(address.family, &address.address);
+ if (r < 0) {
+ log_warning_errno(r, "/etc/hosts:%u: address '%s' is invalid, ignoring: %m", nr, address_str);
+ return 0;
+ }
if (r > 0)
/* This is an 0.0.0.0 or :: item, which we assume means that we shall map the specified hostname to
* nothing. */
item = NULL;
else {
- /* If this is a normal address, then, simply add entry mapping it to the specified names */
+ /* If this is a normal address, then simply add entry mapping it to the specified names */
- item = set_get(m->etc_hosts_by_address, &key);
- if (item) {
- r = strv_extend_strv(&item->names, names, true);
- if (r < 0)
- return log_oom();
- } else {
-
- r = set_ensure_allocated(&m->etc_hosts_by_address, &etc_hosts_item_ops);
+ item = hashmap_get(hosts->by_address, &address);
+ if (!item) {
+ r = hashmap_ensure_allocated(&hosts->by_address, &in_addr_data_hash_ops);
if (r < 0)
return log_oom();
@@ -116,11 +77,9 @@ static int add_item(Manager *m, int family, const union in_addr_union *address,
if (!item)
return log_oom();
- item->family = family;
- item->address = *address;
- item->names = names;
+ item->address = address;
- r = set_put(m->etc_hosts_by_address, item);
+ r = hashmap_put(hosts->by_address, &item->address, item);
if (r < 0) {
free(item);
return log_oom();
@@ -128,12 +87,51 @@ static int add_item(Manager *m, int family, const union in_addr_union *address,
}
}
- STRV_FOREACH(n, names) {
+ for (;;) {
+ _cleanup_free_ char *name = NULL;
EtcHostsItemByName *bn;
- bn = hashmap_get(m->etc_hosts_by_name, *n);
+ r = extract_first_word(&line, &name, NULL, EXTRACT_RELAX);
+ if (r < 0)
+ return log_error_errno(r, "/etc/hosts:%u: couldn't extract host name: %m", nr);
+ if (r == 0)
+ break;
+
+ found = true;
+
+ r = dns_name_is_valid_ldh(name);
+ if (r <= 0) {
+ log_warning_errno(r, "/etc/hosts:%u: hostname \"%s\" is not valid, ignoring.", nr, name);
+ continue;
+ }
+
+ if (is_localhost(name))
+ /* Suppress the "localhost" line that is often seen */
+ continue;
+
+ if (!item) {
+ /* Optimize the case where we don't need to store any addresses, by storing
+ * only the name in a dedicated Set instead of the hashmap */
+
+ r = set_ensure_allocated(&hosts->no_address, &dns_name_hash_ops);
+ if (r < 0)
+ return log_oom();
+
+ r = set_put(hosts->no_address, name);
+ if (r < 0)
+ return r;
+
+ TAKE_PTR(name);
+ continue;
+ }
+
+ r = strv_extend(&item->names, name);
+ if (r < 0)
+ return log_oom();
+
+ bn = hashmap_get(hosts->by_name, name);
if (!bn) {
- r = hashmap_ensure_allocated(&m->etc_hosts_by_name, &dns_name_hash_ops);
+ r = hashmap_ensure_allocated(&hosts->by_name, &dns_name_hash_ops);
if (r < 0)
return log_oom();
@@ -141,103 +139,67 @@ static int add_item(Manager *m, int family, const union in_addr_union *address,
if (!bn)
return log_oom();
- bn->name = strdup(*n);
- if (!bn->name) {
- free(bn);
- return log_oom();
- }
-
- r = hashmap_put(m->etc_hosts_by_name, bn->name, bn);
+ r = hashmap_put(hosts->by_name, name, bn);
if (r < 0) {
- free(bn->name);
free(bn);
return log_oom();
}
+
+ bn->name = TAKE_PTR(name);
}
- if (item) {
- if (!GREEDY_REALLOC(bn->items, bn->n_allocated, bn->n_items+1))
- return log_oom();
+ if (!GREEDY_REALLOC(bn->addresses, bn->n_allocated, bn->n_addresses + 1))
+ return log_oom();
- bn->items[bn->n_items++] = item;
- }
+ bn->addresses[bn->n_addresses++] = &item->address;
}
+ if (!found)
+ log_warning("/etc/hosts:%u: line is missing any host names", nr);
+
return 0;
}
-static int parse_line(Manager *m, unsigned nr, const char *line) {
- _cleanup_free_ char *address = NULL;
- _cleanup_strv_free_ char **names = NULL;
- union in_addr_union in;
- bool suppressed = false;
- int family, r;
-
- assert(m);
- assert(line);
-
- r = extract_first_word(&line, &address, NULL, EXTRACT_RELAX);
- if (r < 0)
- return log_error_errno(r, "Couldn't extract address, in line /etc/hosts:%u.", nr);
- if (r == 0) {
- log_error("Premature end of line, in line /etc/hosts:%u.", nr);
- return -EINVAL;
- }
-
- r = in_addr_from_string_auto(address, &family, &in);
- if (r < 0)
- return log_error_errno(r, "Address '%s' is invalid, in line /etc/hosts:%u.", address, nr);
+int etc_hosts_parse(EtcHosts *hosts, FILE *f) {
+ _cleanup_(etc_hosts_free) EtcHosts t = {};
+ unsigned nr = 0;
+ int r;
for (;;) {
- _cleanup_free_ char *name = NULL;
+ _cleanup_free_ char *line = NULL;
+ char *l;
- r = extract_first_word(&line, &name, NULL, EXTRACT_RELAX);
+ r = read_line(f, LONG_LINE_MAX, &line);
if (r < 0)
- return log_error_errno(r, "Couldn't extract host name, in line /etc/hosts:%u.", nr);
+ return log_error_errno(r, "Failed to read /etc/hosts: %m");
if (r == 0)
break;
- r = dns_name_is_valid(name);
- if (r <= 0)
- return log_error_errno(r, "Hostname %s is not valid, ignoring, in line /etc/hosts:%u.", name, nr);
+ nr++;
- if (is_localhost(name)) {
- /* Suppress the "localhost" line that is often seen */
- suppressed = true;
+ l = strchr(line, '#');
+ if (l)
+ *l = '\0';
+
+ l = strstrip(line);
+ if (isempty(l))
continue;
- }
- r = strv_push(&names, name);
+ r = parse_line(&t, nr, l);
if (r < 0)
- return log_oom();
-
- name = NULL;
- }
-
- if (strv_isempty(names)) {
-
- if (suppressed)
- return 0;
-
- log_error("Line is missing any host names, in line /etc/hosts:%u.", nr);
- return -EINVAL;
+ return r;
}
- /* Takes possession of the names strv */
- r = add_item(m, family, &in, names);
- if (r < 0)
- return r;
-
- names = NULL;
- return r;
+ etc_hosts_free(hosts);
+ *hosts = t;
+ t = (EtcHosts) {}; /* prevent cleanup */
+ return 0;
}
-int manager_etc_hosts_read(Manager *m) {
+static int manager_etc_hosts_read(Manager *m) {
_cleanup_fclose_ FILE *f = NULL;
- char line[LINE_MAX];
struct stat st;
usec_t ts;
- unsigned nr = 0;
int r;
assert_se(sd_event_now(m->event, clock_boottime_or_monotonic(), &ts) >= 0);
@@ -250,12 +212,11 @@ int manager_etc_hosts_read(Manager *m) {
if (m->etc_hosts_mtime != USEC_INFINITY) {
if (stat("/etc/hosts", &st) < 0) {
- if (errno == ENOENT) {
- r = 0;
- goto clear;
- }
+ if (errno != ENOENT)
+ return log_error_errno(errno, "Failed to stat /etc/hosts: %m");
- return log_error_errno(errno, "Failed to stat /etc/hosts: %m");
+ manager_etc_hosts_flush(m);
+ return 0;
}
/* Did the mtime change? If not, there's no point in re-reading the file. */
@@ -265,12 +226,11 @@ int manager_etc_hosts_read(Manager *m) {
f = fopen("/etc/hosts", "re");
if (!f) {
- if (errno == ENOENT) {
- r = 0;
- goto clear;
- }
+ if (errno != ENOENT)
+ return log_error_errno(errno, "Failed to open /etc/hosts: %m");
- return log_error_errno(errno, "Failed to open /etc/hosts: %m");
+ manager_etc_hosts_flush(m);
+ return 0;
}
/* Take the timestamp at the beginning of processing, so that any changes made later are read on the next
@@ -279,38 +239,20 @@ int manager_etc_hosts_read(Manager *m) {
if (r < 0)
return log_error_errno(errno, "Failed to fstat() /etc/hosts: %m");
- manager_etc_hosts_flush(m);
-
- FOREACH_LINE(line, f, return log_error_errno(errno, "Failed to read /etc/hosts: %m")) {
- char *l;
-
- nr++;
-
- l = strstrip(line);
- if (isempty(l))
- continue;
- if (l[0] == '#')
- continue;
-
- r = parse_line(m, nr, l);
- if (r == -ENOMEM) /* On OOM we abandon the half-built-up structure. All other errors we ignore and proceed */
- goto clear;
- }
+ r = etc_hosts_parse(&m->etc_hosts, f);
+ if (r < 0)
+ return r;
m->etc_hosts_mtime = timespec_load(&st.st_mtim);
m->etc_hosts_last = ts;
return 1;
-
-clear:
- manager_etc_hosts_flush(m);
- return r;
}
int manager_etc_hosts_lookup(Manager *m, DnsQuestion* q, DnsAnswer **answer) {
bool found_a = false, found_aaaa = false;
+ struct in_addr_data k = {};
EtcHostsItemByName *bn;
- EtcHostsItem k = {};
DnsResourceKey *t;
const char *name;
unsigned i;
@@ -320,9 +262,10 @@ int manager_etc_hosts_lookup(Manager *m, DnsQuestion* q, DnsAnswer **answer) {
assert(q);
assert(answer);
- r = manager_etc_hosts_read(m);
- if (r < 0)
- return r;
+ if (!m->read_etc_hosts)
+ return 0;
+
+ (void) manager_etc_hosts_read(m);
name = dns_question_first_name(q);
if (!name)
@@ -333,7 +276,7 @@ int manager_etc_hosts_lookup(Manager *m, DnsQuestion* q, DnsAnswer **answer) {
EtcHostsItem *item;
DnsResourceKey *found_ptr = NULL;
- item = set_get(m->etc_hosts_by_address, &k);
+ item = hashmap_get(m->etc_hosts.by_address, &k);
if (!item)
return 0;
@@ -382,13 +325,16 @@ int manager_etc_hosts_lookup(Manager *m, DnsQuestion* q, DnsAnswer **answer) {
return 1;
}
- bn = hashmap_get(m->etc_hosts_by_name, name);
- if (!bn)
- return 0;
-
- r = dns_answer_reserve(answer, bn->n_items);
- if (r < 0)
- return r;
+ bn = hashmap_get(m->etc_hosts.by_name, name);
+ if (bn) {
+ r = dns_answer_reserve(answer, bn->n_addresses);
+ if (r < 0)
+ return r;
+ } else {
+ /* Check if name was listed with no address. If yes, continue to return an answer. */
+ if (!set_contains(m->etc_hosts.no_address, name))
+ return 0;
+ }
DNS_QUESTION_FOREACH(t, q) {
if (!IN_SET(t->type, DNS_TYPE_A, DNS_TYPE_AAAA, DNS_TYPE_ANY))
@@ -411,14 +357,14 @@ int manager_etc_hosts_lookup(Manager *m, DnsQuestion* q, DnsAnswer **answer) {
break;
}
- for (i = 0; i < bn->n_items; i++) {
+ for (i = 0; bn && i < bn->n_addresses; i++) {
_cleanup_(dns_resource_record_unrefp) DnsResourceRecord *rr = NULL;
- if ((!found_a && bn->items[i]->family == AF_INET) ||
- (!found_aaaa && bn->items[i]->family == AF_INET6))
+ if ((!found_a && bn->addresses[i]->family == AF_INET) ||
+ (!found_aaaa && bn->addresses[i]->family == AF_INET6))
continue;
- r = dns_resource_record_new_address(&rr, bn->items[i]->family, &bn->items[i]->address, bn->name);
+ r = dns_resource_record_new_address(&rr, bn->addresses[i]->family, &bn->addresses[i]->address, bn->name);
if (r < 0)
return r;
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