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https://github.com/systemd/systemd-stable.git
synced 2024-10-28 03:25:27 +03:00
resolved: put /etc/hosts hashmaps in a structure and pass that around
This hides the details of juggling the two hashmaps from the callers a bit. It also makes memory management a bit easier, because those two hashmaps share some strings, so we can only free them together. etc_hosts_parse() is made responsible to free the half-filled data structures on error, which makes the caller a bit simpler. No functional change. A refactoring to prepare for later changes.
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8d732e2f71
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@ -25,35 +25,35 @@ typedef struct EtcHostsItemByName {
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size_t n_addresses, n_allocated;
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} EtcHostsItemByName;
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void manager_etc_hosts_flush(Manager *m) {
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EtcHostsItem *item;
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EtcHostsItemByName *bn;
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while ((item = hashmap_steal_first(m->etc_hosts_by_address))) {
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static inline void etc_hosts_item_free(EtcHostsItem *item) {
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strv_free(item->names);
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free(item);
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}
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}
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while ((bn = hashmap_steal_first(m->etc_hosts_by_name))) {
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free(bn->name);
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free(bn->addresses);
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free(bn);
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}
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static inline void etc_hosts_item_by_name_free(EtcHostsItemByName *item) {
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free(item->name);
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free(item->addresses);
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free(item);
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}
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m->etc_hosts_by_address = hashmap_free(m->etc_hosts_by_address);
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m->etc_hosts_by_name = hashmap_free(m->etc_hosts_by_name);
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static void etc_hosts_free(EtcHosts *hosts) {
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hosts->by_address = hashmap_free_with_destructor(hosts->by_address, etc_hosts_item_free);
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hosts->by_name = hashmap_free_with_destructor(hosts->by_name, etc_hosts_item_by_name_free);
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}
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void manager_etc_hosts_flush(Manager *m) {
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etc_hosts_free(&m->etc_hosts);
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m->etc_hosts_mtime = USEC_INFINITY;
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}
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static int parse_line(Manager *m, unsigned nr, const char *line) {
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static int parse_line(EtcHosts *hosts, unsigned nr, const char *line) {
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_cleanup_free_ char *address_str = NULL;
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struct in_addr_data address = {};
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bool suppressed = false;
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EtcHostsItem *item;
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int r;
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assert(m);
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assert(hosts);
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assert(line);
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r = extract_first_word(&line, &address_str, NULL, EXTRACT_RELAX);
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@ -78,9 +78,9 @@ static int parse_line(Manager *m, unsigned nr, const char *line) {
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else {
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/* If this is a normal address, then, simply add entry mapping it to the specified names */
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item = hashmap_get(m->etc_hosts_by_address, &address);
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item = hashmap_get(hosts->by_address, &address);
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if (!item) {
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r = hashmap_ensure_allocated(&m->etc_hosts_by_address, &in_addr_data_hash_ops);
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r = hashmap_ensure_allocated(&hosts->by_address, &in_addr_data_hash_ops);
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if (r < 0)
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return log_oom();
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@ -90,7 +90,7 @@ static int parse_line(Manager *m, unsigned nr, const char *line) {
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item->address = address;
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r = hashmap_put(m->etc_hosts_by_address, &item->address, item);
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r = hashmap_put(hosts->by_address, &item->address, item);
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if (r < 0) {
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free(item);
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return log_oom();
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@ -124,9 +124,9 @@ static int parse_line(Manager *m, unsigned nr, const char *line) {
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return log_oom();
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}
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bn = hashmap_get(m->etc_hosts_by_name, name);
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bn = hashmap_get(hosts->by_name, name);
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if (!bn) {
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r = hashmap_ensure_allocated(&m->etc_hosts_by_name, &dns_name_hash_ops);
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r = hashmap_ensure_allocated(&hosts->by_name, &dns_name_hash_ops);
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if (r < 0)
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return log_oom();
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@ -134,7 +134,7 @@ static int parse_line(Manager *m, unsigned nr, const char *line) {
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if (!bn)
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return log_oom();
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r = hashmap_put(m->etc_hosts_by_name, name, bn);
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r = hashmap_put(hosts->by_name, name, bn);
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if (r < 0) {
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free(bn);
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return log_oom();
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@ -161,55 +161,12 @@ static int parse_line(Manager *m, unsigned nr, const char *line) {
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return 0;
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}
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static int manager_etc_hosts_read(Manager *m) {
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_cleanup_fclose_ FILE *f = NULL;
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static int etc_hosts_parse(EtcHosts *hosts, FILE *f) {
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_cleanup_(etc_hosts_free) EtcHosts t = {};
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char line[LINE_MAX];
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struct stat st;
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usec_t ts;
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unsigned nr = 0;
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int r;
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assert_se(sd_event_now(m->event, clock_boottime_or_monotonic(), &ts) >= 0);
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/* See if we checked /etc/hosts recently already */
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if (m->etc_hosts_last != USEC_INFINITY && m->etc_hosts_last + ETC_HOSTS_RECHECK_USEC > ts)
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return 0;
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m->etc_hosts_last = ts;
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if (m->etc_hosts_mtime != USEC_INFINITY) {
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if (stat("/etc/hosts", &st) < 0) {
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if (errno == ENOENT) {
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r = 0;
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goto clear;
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}
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return log_error_errno(errno, "Failed to stat /etc/hosts: %m");
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}
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/* Did the mtime change? If not, there's no point in re-reading the file. */
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if (timespec_load(&st.st_mtim) == m->etc_hosts_mtime)
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return 0;
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}
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f = fopen("/etc/hosts", "re");
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if (!f) {
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if (errno == ENOENT) {
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r = 0;
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goto clear;
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}
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return log_error_errno(errno, "Failed to open /etc/hosts: %m");
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}
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/* Take the timestamp at the beginning of processing, so that any changes made later are read on the next
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* invocation */
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r = fstat(fileno(f), &st);
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if (r < 0)
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return log_error_errno(errno, "Failed to fstat() /etc/hosts: %m");
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manager_etc_hosts_flush(m);
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FOREACH_LINE(line, f, return log_error_errno(errno, "Failed to read /etc/hosts: %m")) {
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char *l;
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@ -221,19 +178,70 @@ static int manager_etc_hosts_read(Manager *m) {
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if (l[0] == '#')
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continue;
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r = parse_line(m, nr, l);
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if (r == -ENOMEM) /* On OOM we abandon the half-built-up structure. All other errors we ignore and proceed */
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goto clear;
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r = parse_line(&t, nr, l);
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if (r < 0)
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return r;
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}
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*hosts = t;
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t = (EtcHosts) {}; /* prevent cleanup */
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return 0;
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}
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static int manager_etc_hosts_read(Manager *m) {
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_cleanup_fclose_ FILE *f = NULL;
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struct stat st;
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usec_t ts;
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int r;
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assert_se(sd_event_now(m->event, clock_boottime_or_monotonic(), &ts) >= 0);
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/* See if we checked /etc/hosts recently already */
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if (m->etc_hosts_last != USEC_INFINITY && m->etc_hosts_last + ETC_HOSTS_RECHECK_USEC > ts)
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return 0;
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m->etc_hosts_last = ts;
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if (m->etc_hosts_mtime != USEC_INFINITY) {
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if (stat("/etc/hosts", &st) < 0) {
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if (errno != ENOENT)
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return log_error_errno(errno, "Failed to stat /etc/hosts: %m");
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manager_etc_hosts_flush(m);
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return 0;
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}
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/* Did the mtime change? If not, there's no point in re-reading the file. */
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if (timespec_load(&st.st_mtim) == m->etc_hosts_mtime)
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return 0;
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}
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f = fopen("/etc/hosts", "re");
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if (!f) {
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if (errno != ENOENT)
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return log_error_errno(errno, "Failed to open /etc/hosts: %m");
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manager_etc_hosts_flush(m);
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return 0;
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}
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/* Take the timestamp at the beginning of processing, so that any changes made later are read on the next
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* invocation */
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r = fstat(fileno(f), &st);
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if (r < 0)
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return log_error_errno(errno, "Failed to fstat() /etc/hosts: %m");
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manager_etc_hosts_flush(m);
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r = etc_hosts_parse(&m->etc_hosts, f);
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if (r == -ENOMEM)
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/* On OOM we bail. All other errors we ignore and proceed. */
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return r;
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m->etc_hosts_mtime = timespec_load(&st.st_mtim);
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m->etc_hosts_last = ts;
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return 1;
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clear:
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manager_etc_hosts_flush(m);
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return r;
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}
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int manager_etc_hosts_lookup(Manager *m, DnsQuestion* q, DnsAnswer **answer) {
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@ -265,7 +273,7 @@ int manager_etc_hosts_lookup(Manager *m, DnsQuestion* q, DnsAnswer **answer) {
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EtcHostsItem *item;
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DnsResourceKey *found_ptr = NULL;
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item = hashmap_get(m->etc_hosts_by_address, &k);
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item = hashmap_get(m->etc_hosts.by_address, &k);
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if (!item)
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return 0;
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@ -314,7 +322,7 @@ int manager_etc_hosts_lookup(Manager *m, DnsQuestion* q, DnsAnswer **answer) {
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return 1;
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}
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bn = hashmap_get(m->etc_hosts_by_name, name);
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bn = hashmap_get(m->etc_hosts.by_name, name);
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if (!bn)
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return 0;
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@ -23,6 +23,11 @@ typedef struct Manager Manager;
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#define MANAGER_SEARCH_DOMAINS_MAX 32
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#define MANAGER_DNS_SERVERS_MAX 32
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typedef struct EtcHosts {
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Hashmap *by_address;
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Hashmap *by_name;
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} EtcHosts;
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struct Manager {
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sd_event *event;
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@ -114,8 +119,7 @@ struct Manager {
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unsigned n_dnssec_verdict[_DNSSEC_VERDICT_MAX];
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/* Data from /etc/hosts */
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Hashmap* etc_hosts_by_address;
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Hashmap* etc_hosts_by_name;
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EtcHosts etc_hosts;
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usec_t etc_hosts_last, etc_hosts_mtime;
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bool read_etc_hosts;
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