ipc: cache windows lookups to avoid O(n^2) with nested lookups
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
This commit is contained in:
parent
f65c82456d
commit
d58df7ed10
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@ -10,6 +10,7 @@
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#include <stdio.h>
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#include <stdbool.h>
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#include <fcntl.h>
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#include <hashtable.h>
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static FILE *userspace_interface_file(const char *iface)
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{
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@ -113,6 +114,9 @@ err:
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return NULL;
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}
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static bool have_cached_interfaces;
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static struct hashtable cached_interfaces;
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static bool userspace_has_wireguard_interface(const char *iface)
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{
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char fname[MAX_PATH];
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@ -120,10 +124,13 @@ static bool userspace_has_wireguard_interface(const char *iface)
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HANDLE find_handle;
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bool ret = false;
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if (have_cached_interfaces)
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return hashtable_find_entry(&cached_interfaces, iface) != NULL;
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snprintf(fname, sizeof(fname), "ProtectedPrefix\\Administrators\\WireGuard\\%s", iface);
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find_handle = FindFirstFile("\\\\.\\pipe\\*", &find_data);
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if (find_handle == INVALID_HANDLE_VALUE)
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return -GetLastError();
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return -EIO;
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do {
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if (!strcmp(fname, find_data.cFileName)) {
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ret = true;
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@ -139,18 +146,25 @@ static int userspace_get_wireguard_interfaces(struct string_list *list)
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static const char prefix[] = "ProtectedPrefix\\Administrators\\WireGuard\\";
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WIN32_FIND_DATA find_data;
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HANDLE find_handle;
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char *iface;
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int ret = 0;
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find_handle = FindFirstFile("\\\\.\\pipe\\*", &find_data);
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if (find_handle == INVALID_HANDLE_VALUE)
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return -GetLastError();
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return -EIO;
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do {
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if (strncmp(prefix, find_data.cFileName, strlen(prefix)))
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continue;
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ret = string_list_add(list, find_data.cFileName + strlen(prefix));
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iface = find_data.cFileName + strlen(prefix);
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ret = string_list_add(list, iface);
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if (ret < 0)
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goto out;
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if (!hashtable_find_or_insert_entry(&cached_interfaces, iface)) {
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ret = -errno;
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goto out;
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}
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} while (FindNextFile(find_handle, &find_data));
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have_cached_interfaces = true;
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out:
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FindClose(find_handle);
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@ -13,12 +13,17 @@
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#include <ddk/ndisguid.h>
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#include <nci.h>
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#include <wireguard.h>
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#include <hashtable.h>
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#define IPC_SUPPORTS_KERNEL_INTERFACE
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static bool have_cached_kernel_interfaces;
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static struct hashtable cached_kernel_interfaces;
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static int kernel_get_wireguard_interfaces(struct string_list *list)
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{
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HDEVINFO dev_info = SetupDiGetClassDevsExW(&GUID_DEVCLASS_NET, NULL, NULL, DIGCF_PRESENT, NULL, NULL, NULL);
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bool will_have_cached_kernel_interfaces = true;
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if (dev_info == INVALID_HANDLE_VALUE) {
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errno = EACCES;
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@ -33,6 +38,7 @@ static int kernel_get_wireguard_interfaces(struct string_list *list)
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HKEY key;
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GUID instance_id;
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char *interface_name;
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struct hashtable_entry *entry;
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if (!SetupDiEnumDeviceInfo(dev_info, i, &dev_info_data)) {
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if (GetLastError() == ERROR_NO_MORE_ITEMS)
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@ -105,7 +111,25 @@ static int kernel_get_wireguard_interfaces(struct string_list *list)
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}
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string_list_add(list, interface_name);
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entry = hashtable_find_or_insert_entry(&cached_kernel_interfaces, interface_name);
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free(interface_name);
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if (!entry)
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goto cleanup_entry;
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if (SetupDiGetDeviceInstanceIdW(dev_info, &dev_info_data, NULL, 0, &buf_len) || GetLastError() != ERROR_INSUFFICIENT_BUFFER)
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goto cleanup_entry;
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entry->value = calloc(sizeof(WCHAR), buf_len);
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if (!entry->value)
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goto cleanup_entry;
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if (!SetupDiGetDeviceInstanceIdW(dev_info, &dev_info_data, entry->value, buf_len, &buf_len)) {
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free(entry->value);
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entry->value = NULL;
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goto cleanup_entry;
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}
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cleanup_entry:
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will_have_cached_kernel_interfaces |= entry != NULL && entry->value != NULL;
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cleanup_buf:
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free(buf);
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cleanup_key:
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@ -113,15 +137,48 @@ cleanup_key:
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skip:;
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}
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SetupDiDestroyDeviceInfoList(dev_info);
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have_cached_kernel_interfaces = will_have_cached_kernel_interfaces;
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return 0;
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}
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static HANDLE kernel_interface_handle(const char *iface)
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{
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HDEVINFO dev_info = SetupDiGetClassDevsExW(&GUID_DEVCLASS_NET, NULL, NULL, DIGCF_PRESENT, NULL, NULL, NULL);
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HDEVINFO dev_info;
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WCHAR *interfaces = NULL;
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HANDLE handle;
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if (have_cached_kernel_interfaces) {
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struct hashtable_entry *entry = hashtable_find_entry(&cached_kernel_interfaces, iface);
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if (entry) {
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DWORD buf_len;
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if (CM_Get_Device_Interface_List_SizeW(
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&buf_len, (GUID *)&GUID_DEVINTERFACE_NET, (DEVINSTID_W)entry->value,
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CM_GET_DEVICE_INTERFACE_LIST_PRESENT) != CR_SUCCESS)
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goto err_hash;
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interfaces = calloc(buf_len, sizeof(*interfaces));
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if (!interfaces)
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goto err_hash;
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if (CM_Get_Device_Interface_ListW(
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(GUID *)&GUID_DEVINTERFACE_NET, (DEVINSTID_W)entry->value, interfaces, buf_len,
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CM_GET_DEVICE_INTERFACE_LIST_PRESENT) != CR_SUCCESS || !interfaces[0]) {
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free(interfaces);
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interfaces = NULL;
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goto err_hash;
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}
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handle = CreateFileW(interfaces, GENERIC_READ | GENERIC_WRITE,
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FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL,
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OPEN_EXISTING, 0, NULL);
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free(interfaces);
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if (handle == INVALID_HANDLE_VALUE)
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goto err_hash;
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return handle;
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err_hash:
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errno = EACCES;
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return NULL;
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}
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}
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dev_info = SetupDiGetClassDevsExW(&GUID_DEVCLASS_NET, NULL, NULL, DIGCF_PRESENT, NULL, NULL, NULL);
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if (dev_info == INVALID_HANDLE_VALUE)
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return NULL;
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@ -0,0 +1,61 @@
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/* SPDX-License-Identifier: GPL-2.0
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*
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* Copyright (C) 2018-2021 WireGuard LLC. All Rights Reserved.
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*/
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#ifndef _HASHTABLE_H
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#define _HASHTABLE_H
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#include <string.h>
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enum { HASHTABLE_ENTRY_BUCKETS_POW2 = 1 << 10 };
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struct hashtable_entry {
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char *key;
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void *value;
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struct hashtable_entry *next;
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};
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struct hashtable {
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struct hashtable_entry *entry_buckets[HASHTABLE_ENTRY_BUCKETS_POW2];
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};
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static unsigned int hashtable_bucket(const char *str)
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{
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unsigned long hash = 5381;
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char c;
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while ((c = *str++))
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hash = ((hash << 5) + hash) ^ c;
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return hash & (HASHTABLE_ENTRY_BUCKETS_POW2 - 1);
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}
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static struct hashtable_entry *hashtable_find_entry(struct hashtable *hashtable, const char *key)
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{
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struct hashtable_entry *entry;
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for (entry = hashtable->entry_buckets[hashtable_bucket(key)]; entry; entry = entry->next) {
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if (!strcmp(entry->key, key))
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return entry;
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}
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return NULL;
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}
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static struct hashtable_entry *hashtable_find_or_insert_entry(struct hashtable *hashtable, const char *key)
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{
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struct hashtable_entry **entry;
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for (entry = &hashtable->entry_buckets[hashtable_bucket(key)]; *entry; entry = &(*entry)->next) {
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if (!strcmp((*entry)->key, key))
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return *entry;
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}
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*entry = calloc(1, sizeof(**entry));
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if (!*entry)
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return NULL;
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(*entry)->key = strdup(key);
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if (!(*entry)->key) {
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free(*entry);
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*entry = NULL;
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return NULL;
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}
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return *entry;
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}
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#endif
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