diff options
author | Patrik Nyblom <pan@erlang.org> | 2011-05-26 18:41:51 +0200 |
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committer | Patrik Nyblom <pan@erlang.org> | 2011-05-26 18:41:51 +0200 |
commit | 62ff4caa39235fd0ba30b51f419309fcba06001d (patch) | |
tree | 8e82111a1a0f9d0fece38c6407033ef88a80560a /erts/etc/win32 | |
parent | 41e6d95c4ca11598a5eb93901ce2fb0b758e9657 (diff) | |
download | otp-62ff4caa39235fd0ba30b51f419309fcba06001d.tar.gz otp-62ff4caa39235fd0ba30b51f419309fcba06001d.tar.bz2 otp-62ff4caa39235fd0ba30b51f419309fcba06001d.zip |
Add global lock for erlsrv to avoid races
Diffstat (limited to 'erts/etc/win32')
-rw-r--r-- | erts/etc/win32/erlsrv/erlsrv_interactive.c | 140 | ||||
-rw-r--r-- | erts/etc/win32/erlsrv/erlsrv_interactive.h | 2 |
2 files changed, 120 insertions, 22 deletions
diff --git a/erts/etc/win32/erlsrv/erlsrv_interactive.c b/erts/etc/win32/erlsrv/erlsrv_interactive.c index 13e029b364..8910be103b 100644 --- a/erts/etc/win32/erlsrv/erlsrv_interactive.c +++ b/erts/etc/win32/erlsrv/erlsrv_interactive.c @@ -841,6 +841,7 @@ int do_add_or_set(int argc, char **argv){ argv[0], service_name); return 0; } + int do_rename(int argc, char **argv){ RegEntry *current = empty_reg_tab(); RegEntry *dummy = empty_reg_tab(); @@ -1129,35 +1130,130 @@ void read_arguments(int *pargc, char ***pargv){ *pargc = argc; *pargv = argv; } + +/* Create a free-for-all ACL to set on the semaphore */ +PACL get_acl(PSECURITY_DESCRIPTOR secdescp) +{ + DWORD acl_length = 0; + PSID auth_users_sidp = NULL; + PACL aclp = NULL; + SID_IDENTIFIER_AUTHORITY ntauth = SECURITY_NT_AUTHORITY; + + if(!InitializeSecurityDescriptor(secdescp, SECURITY_DESCRIPTOR_REVISION)) { + return NULL; + } + + if(!AllocateAndInitializeSid(&ntauth, + 1, + SECURITY_AUTHENTICATED_USER_RID, + 0, 0, 0, 0, 0, 0, 0, + &auth_users_sidp)) { + return NULL; + } + + acl_length = sizeof(ACL) + + sizeof(ACCESS_ALLOWED_ACE) - sizeof(DWORD) + + GetLengthSid(auth_users_sidp); + + if((aclp = (PACL) HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, acl_length)) == NULL) { + FreeSid(auth_users_sidp); + return NULL; + } + + if(!InitializeAcl(aclp, acl_length, ACL_REVISION)) { + FreeSid(auth_users_sidp); + HeapFree(GetProcessHeap(), 0, aclp); + return NULL; + } + + if(!AddAccessAllowedAce(aclp, ACL_REVISION, SEMAPHORE_ALL_ACCESS, auth_users_sidp)) { + FreeSid(auth_users_sidp); + HeapFree(GetProcessHeap(), 0, aclp); + return NULL; + } + + if(!SetSecurityDescriptorDacl(secdescp, TRUE, aclp, FALSE)) { + FreeSid(auth_users_sidp); + HeapFree(GetProcessHeap(), 0, aclp); + return NULL; + } + return aclp; +} + +static HANDLE lock_semaphore = NULL; + +int take_lock(void) { + SECURITY_ATTRIBUTES attr; + PACL aclp; + SECURITY_DESCRIPTOR secdesc; + + if ((aclp = get_acl(&secdesc)) == NULL) { + return -1; + } + + memset(&attr,0,sizeof(attr)); + attr.nLength = sizeof(attr); + attr.lpSecurityDescriptor = &secdesc; + attr.bInheritHandle = FALSE; + + if ((lock_semaphore = CreateSemaphore(&attr, 1, 1, ERLSRV_INTERACTIVE_GLOBAL_SEMAPHORE)) == NULL) { + return -1; + } + + if (WaitForSingleObject(lock_semaphore,INFINITE) != WAIT_OBJECT_0) { + return -1; + } + + HeapFree(GetProcessHeap(), 0, aclp); + return 0; +} + +void release_lock(void) { + ReleaseSemaphore(lock_semaphore,1,NULL); +} + int interactive_main(int argc, char **argv){ char *action = argv[1]; - + int res; + + if (take_lock() != 0) { + fprintf(stderr,"%s: unable to acquire global lock (%s).\n",argv[0], + ERLSRV_INTERACTIVE_GLOBAL_SEMAPHORE); + return 1; + } + if(!_stricmp(action,"readargs")){ - read_arguments(&argc,&argv); - action = argv[1]; + read_arguments(&argc,&argv); + action = argv[1]; } if(!_stricmp(action,"set") || !_stricmp(action,"add")) - return do_add_or_set(argc,argv); - if(!_stricmp(action,"rename")) - return do_rename(argc,argv); - if(!_stricmp(action,"remove")) - return do_remove(argc,argv); - if(!_stricmp(action,"list")) - return do_list(argc,argv); - if(!_stricmp(action,"start") || - !_stricmp(action,"stop") || - !_stricmp(action,"enable") || - !_stricmp(action,"disable")) - return do_manage(argc,argv); - if(_stricmp(action,"?") && - _stricmp(action,"/?") && - _stricmp(action,"-?") && - *action != 'h' && - *action != 'H') + res = do_add_or_set(argc,argv); + else if(!_stricmp(action,"rename")) + res = do_rename(argc,argv); + else if(!_stricmp(action,"remove")) + res = do_remove(argc,argv); + else if(!_stricmp(action,"list")) + res = do_list(argc,argv); + else if(!_stricmp(action,"start") || + !_stricmp(action,"stop") || + !_stricmp(action,"enable") || + !_stricmp(action,"disable")) + res = do_manage(argc,argv); + else if(_stricmp(action,"?") && + _stricmp(action,"/?") && + _stricmp(action,"-?") && + *action != 'h' && + *action != 'H') { fprintf(stderr,"%s: action %s not implemented.\n",argv[0],action); - do_usage(argv[0]); - return 1; + do_usage(argv[0]); + res = 1; + } else { + do_usage(argv[0]); + res = 0; + } + release_lock(); + return res; } diff --git a/erts/etc/win32/erlsrv/erlsrv_interactive.h b/erts/etc/win32/erlsrv/erlsrv_interactive.h index deacf81899..602da24575 100644 --- a/erts/etc/win32/erlsrv/erlsrv_interactive.h +++ b/erts/etc/win32/erlsrv/erlsrv_interactive.h @@ -19,6 +19,8 @@ #ifndef _ERLSRV_INTERACTIVE_H #define _ERLSRV_INTERACTIVE_H +#define ERLSRV_INTERACTIVE_GLOBAL_SEMAPHORE "{468d6954-e355-415f-968f-d257cb0feef4}" + int interactive_main(int argc, char **argv); #endif /* _ERLSRV_INTERACTIVE_H */ |