X-Git-Url: https://git.hcoop.net/hcoop/debian/exim4.git/blobdiff_plain/188b6fee0dfdf699a1a302e16b70d17b4f325bcd..2ea97746a3f65eeffb434b8e4e18815e03b61532:/OS/unsupported/os.c-cygwin diff --git a/OS/unsupported/os.c-cygwin b/OS/unsupported/os.c-cygwin new file mode 100644 index 0000000..c9464aa --- /dev/null +++ b/OS/unsupported/os.c-cygwin @@ -0,0 +1,531 @@ +/************************************************* +* Exim - an Internet mail transport agent * +*************************************************/ + +/* Cygwin-specific code. December 2002. Updated Jan 2015. + This is prefixed to the src/os.c file. + + This code was supplied by Pierre A. Humblet +*/ + +/* We need a special mkdir that + allows names starting with // */ +#undef mkdir +int cygwin_mkdir( const char *path, mode_t mode ) +{ + const char * p = path; + if (*p == '/') while(*(p+1) == '/') p++; + return mkdir(p, mode); +} + +#ifndef COMPILE_UTILITY /* Utilities don't need special code */ + +#ifdef INCLUDE_PAM +#include "../pam/pam.c" +#endif +#include + +unsigned int cygwin_WinVersion; + +/* Conflict between Windows definitions and others */ +#ifdef NOERROR +#undef NOERROR +#endif +#ifdef DELETE +#undef DELETE +#endif + +#include +#include +#include + +#define EqualLuid(Luid1, Luid2) \ + ((Luid1.LowPart == Luid2.LowPart) && (Luid1.HighPart == Luid2.HighPart)) +#include + +/* Special static variables */ +static BOOL cygwin_debug = FALSE; +static int fakesetugid = 1; /* when not privileged, setugid = noop */ + +#undef setuid +int cygwin_setuid(uid_t uid ) +{ + int res = 0; + if (fakesetugid == 0) { + res = setuid(uid); + if (cygwin_debug) + fprintf(stderr, "setuid %u %u %d pid: %d\n", + uid, getuid(),res, getpid()); + } + return res; +} + +#undef setgid +int cygwin_setgid(gid_t gid ) +{ + int res = 0; + if (fakesetugid == 0) { + res = setgid(gid); + if (cygwin_debug) + fprintf(stderr, "setgid %u %u %d pid: %d\n", + gid, getgid(), res, getpid()); + } + return res; +} + +/* Background processes run at lower priority */ +static void cygwin_setpriority() +{ + if (!SetPriorityClass(GetCurrentProcess(), BELOW_NORMAL_PRIORITY_CLASS)) + SetPriorityClass(GetCurrentProcess(), IDLE_PRIORITY_CLASS); + return; +} + + +/* GetVersion() + MSB: 1 for 95/98/ME; Next 7: build number, except for 95/98/ME + Next byte: 0 + Next byte: minor version of OS + Low byte: major version of OS (3 or 4 for for NT, 5 for 2000 and XP) */ +//#define VERSION_IS_58M(x) (x & 0x80000000) /* 95, 98, Me */ +//#define VERSION_IS_NT(x) ((x & 0XFF) < 5) /* NT 4 or 3.51 */ + +/* + Routine to find if process or thread is privileged +*/ + +enum { + CREATE_BIT = 1, +}; + +static DWORD get_privileges () +{ + char buffer[1024]; + DWORD i, length; + HANDLE hToken = NULL; + PTOKEN_PRIVILEGES privs; + LUID cluid, rluid; + DWORD ret = 0; + + privs = (PTOKEN_PRIVILEGES) buffer; + + if (OpenProcessToken (GetCurrentProcess(), TOKEN_QUERY, &hToken) + && LookupPrivilegeValue (NULL, SE_CREATE_TOKEN_NAME, &cluid) + && LookupPrivilegeValue(NULL, SE_RESTORE_NAME, &rluid) + && (GetTokenInformation( hToken, TokenPrivileges, + privs, sizeof (buffer), &length) + || (GetLastError () == ERROR_INSUFFICIENT_BUFFER + && (privs = (PTOKEN_PRIVILEGES) alloca (length)) + && GetTokenInformation(hToken, TokenPrivileges, + privs, length, &length)))) { + for (i = 0; i < privs->PrivilegeCount; i++) { + if (EqualLuid(privs->Privileges[i].Luid, cluid)) + ret |= CREATE_BIT; + if (ret == (CREATE_BIT)) + break; + } + } + else + fprintf(stderr, "has_create_token_privilege %u\n", GetLastError()); + + if (hToken) + CloseHandle(hToken); + + return ret; +} + +/* + We use cygwin_premain to fake a few things + and to provide some debug info +*/ +void cygwin_premain2(int argc, char ** argv, struct per_process * ptr) +{ + int i, res, is_daemon = 0, is_spoolwritable, is_privileged, is_eximuser; + uid_t myuid, systemuid; + gid_t mygid, adminsgid; + struct passwd * pwp = NULL; + struct stat buf; + char *cygenv; + SID(1, SystemSid, SECURITY_LOCAL_SYSTEM_RID); + SID(2, AdminsSid, SECURITY_BUILTIN_DOMAIN_RID, DOMAIN_ALIAS_RID_ADMINS); + DWORD priv_flags; + + myuid = getuid(); + mygid = getgid(); + cygwin_WinVersion = GetVersion(); + if ((cygenv = getenv("CYGWIN")) == NULL) cygenv = ""; + /* Produce some debugging on stderr, + cannot yet use exim's debug functions. + Exim does not use -c and ignores -n. + Set lower priority for daemons */ + for (i = 1; i < argc; i++) { + if (argv[i][0] == '-') { + if (argv[i][1] == 'c') { + ssize_t size; + wchar_t *win32_path; + argv[i][1] = 'n'; /* Replace -c by -n */ + cygwin_debug = TRUE; + fprintf(stderr, "CYGWIN = \"%s\".\n", cygenv); + if (((size = cygwin_conv_path(CCP_POSIX_TO_WIN_W,"/", win32_path, 0)) > 0) + && ((win32_path = malloc(size)) != NULL) + && (cygwin_conv_path(CCP_POSIX_TO_WIN_W,"/", win32_path, size) == 0)) { + fprintf(stderr, " Root / mapped to %ls.\n", win32_path); + free(win32_path); + } + } + else if (argv[i][1] == 'b' && argv[i][2] == 'd') { + is_daemon = 1; + cygwin_setpriority(); + } + } + } + + /* Nt/2000/XP + We initially set the exim uid & gid to those of the "exim user", + or to the root uid (SYSTEM) and exim gid (ADMINS), + If privileged, we setuid to those. + We always set the configure uid to the system uid. + We always set the root uid to the real uid + to allow exim imposed restrictions (bypassable by recompiling) + and to avoid exec that cause loss of privilege + If not privileged and unable to chown, + we set the exim uid to our uid. + If unprivileged and /var/spool/exim is writable and not running as listening daemon, + we fake all subsequent setuid. */ + + /* Get the system and admins uid from their sids */ + if ((systemuid = cygwin_internal(CW_GET_UID_FROM_SID, & SystemSid)) == -1) { + fprintf(stderr, "Cannot map System sid. Aborting\n"); + exit(1); + } + if ((adminsgid = cygwin_internal(CW_GET_GID_FROM_SID, & AdminsSid)) == -1) { + fprintf(stderr, "Cannot map Admins sid. Aborting\n"); + exit(1); + } + + priv_flags = get_privileges (); + is_privileged = !!(priv_flags & CREATE_BIT); + + /* Call getpwnam for account exim after getting the local exim name */ + char exim_username[DNLEN + UNLEN + 2]; + if (cygwin_internal(CW_CYGNAME_FROM_WINNAME, "exim", exim_username, sizeof exim_username) != 0) + pwp = getpwnam (exim_username); + + /* If cannot setuid to exim or and is not the daemon (which is assumed to be + able to chown or to be the exim user) set the exim ugid to our ugid to avoid + chown failures after creating files and to be able to setuid to exim in + exim.c ( "privilege not needed" ). */ + if ((is_privileged == 0) && (!is_daemon)) { + exim_uid = myuid; + exim_gid = mygid; + } + else if (pwp != NULL) { + exim_uid = pwp->pw_uid; /* Set it according to passwd */ + exim_gid = pwp->pw_gid; + is_eximuser = 1; + } + else { + exim_uid = systemuid; + exim_gid = adminsgid; + is_eximuser = 0; + } + + res = stat("/var/spool/exim", &buf); + /* Check if writable (and can be stat) */ + is_spoolwritable = ((res == 0) && ((buf.st_mode & S_IWOTH) != 0)); + + fakesetugid = (is_privileged == 0) && (is_daemon == 0) && (is_spoolwritable == 1); + + if (is_privileged) { /* Can setuid */ + if (cygwin_setgid(exim_gid) /* Setuid to exim */ + || cygwin_setuid(exim_uid)) { + fprintf(stderr, "Unable to setuid/gid to exim. priv_flags: %x\n", priv_flags); + exit(0); /* Problem... Perhaps not in 544 */ + } + } + + /* Set the configuration file uid and gid to the system uid and admins gid. */ + config_uid = systemuid; + config_gid = adminsgid; + + /* Pretend we are root to avoid useless exec + and avoid exim set limitations. + We are limited by file access rights */ + root_uid = getuid (); + + if (cygwin_debug) { + fprintf(stderr, "Starting uid %u, gid %u, priv_flags %x, is_privileged %d, is_daemon %d, is_spoolwritable %d.\n", + myuid, mygid, priv_flags, is_privileged, is_daemon, is_spoolwritable); + fprintf(stderr, "root_uid %u, exim_uid %u, exim_gid %u, config_uid %u, config_gid %u, is_eximuser %d.\n", + root_uid, exim_uid, exim_gid, config_uid, config_gid, is_eximuser); + } + return; +} + +#ifndef OS_LOAD_AVERAGE /* Can be set on command line */ +#define OS_LOAD_AVERAGE /* src/os.c need not provide it */ + +/***************************************************************** + Functions for average load measurements + + Uses NtQuerySystemInformation. + This requires definitions that are not part of + standard include files. + + This is discouraged starting with WinXP. + +*************************************************************/ +/* Structure to compute the load average efficiently */ +typedef struct { + DWORD Lock; + unsigned long long Time100ns; /* Last measurement time */ + unsigned long long IdleCount; /* Latest cumulative idle time */ + unsigned long long LastCounter; /* Last measurement counter */ + unsigned long long PerfFreq; /* Perf counter frequency */ + int LastLoad; /* Last reported load, or -1 */ +} cygwin_perf_t; + +static struct { + HANDLE handle; + pid_t pid; + cygwin_perf_t *perf; +} cygwin_load = {NULL, 0, NULL}; + +#include + +typedef enum _SYSTEM_INFORMATION_CLASS +{ + SystemBasicInformation = 0, + SystemPerformanceInformation = 2, + SystemTimeOfDayInformation = 3, + SystemProcessesAndThreadsInformation = 5, + SystemProcessorTimes = 8, + SystemPagefileInformation = 18, + /* There are a lot more of these... */ +} SYSTEM_INFORMATION_CLASS; + +typedef struct _SYSTEM_BASIC_INFORMATION +{ + ULONG Unknown; + ULONG MaximumIncrement; + ULONG PhysicalPageSize; + ULONG NumberOfPhysicalPages; + ULONG LowestPhysicalPage; + ULONG HighestPhysicalPage; + ULONG AllocationGranularity; + ULONG LowestUserAddress; + ULONG HighestUserAddress; + ULONG ActiveProcessors; + UCHAR NumberProcessors; +} SYSTEM_BASIC_INFORMATION, *PSYSTEM_BASIC_INFORMATION; + +typedef struct __attribute__ ((aligned (8))) _SYSTEM_PROCESSOR_TIMES +{ + LARGE_INTEGER IdleTime; + LARGE_INTEGER KernelTime; + LARGE_INTEGER UserTime; + LARGE_INTEGER DpcTime; + LARGE_INTEGER InterruptTime; + ULONG InterruptCount; +} SYSTEM_PROCESSOR_TIMES, *PSYSTEM_PROCESSOR_TIMES; + +typedef NTSTATUS NTAPI (*NtQuerySystemInformation_t) (SYSTEM_INFORMATION_CLASS, PVOID, ULONG, PULONG); +typedef ULONG NTAPI (*RtlNtStatusToDosError_t) (NTSTATUS); + +static NtQuerySystemInformation_t NtQuerySystemInformation; +static RtlNtStatusToDosError_t RtlNtStatusToDosError; + +/***************************************************************** + * + LoadNtdll() + Load special functions from the NTDLL + Return TRUE if success. + + *****************************************************************/ + +static BOOL LoadNtdll() +{ + HINSTANCE hinstLib; + + if ((hinstLib = LoadLibrary("NTDLL.DLL")) + && (NtQuerySystemInformation = + (NtQuerySystemInformation_t) GetProcAddress(hinstLib, + "NtQuerySystemInformation")) + && (RtlNtStatusToDosError = + (RtlNtStatusToDosError_t) GetProcAddress(hinstLib, + "RtlNtStatusToDosError"))) + return TRUE; + + DEBUG(D_load) + debug_printf("perf: load: %u (Windows)\n", GetLastError()); + return FALSE; +} +/***************************************************************** + * + ReadStat() + Measures current Time100ns and IdleCount + Return TRUE if success. + + *****************************************************************/ + +static BOOL ReadStat(unsigned long long int *Time100nsPtr, + unsigned long long int *IdleCountPtr) +{ + NTSTATUS ret; + SYSTEM_BASIC_INFORMATION sbi; + PSYSTEM_PROCESSOR_TIMES spt; + + *Time100nsPtr = *IdleCountPtr = 0; + + if ((ret = NtQuerySystemInformation(SystemBasicInformation, + (PVOID) &sbi, sizeof sbi, NULL)) + != STATUS_SUCCESS) { + DEBUG(D_load) + debug_printf("Perf: NtQuerySystemInformation: %u (Windows)\n", + RtlNtStatusToDosError(ret)); + } + else if (!(spt = (PSYSTEM_PROCESSOR_TIMES) alloca(sizeof(spt[0]) * sbi.NumberProcessors))) { + DEBUG(D_load) + debug_printf("Perf: alloca: errno %d (%s)\n", errno, strerror(errno)); + } + else if ((ret = NtQuerySystemInformation(SystemProcessorTimes, (PVOID) spt, + sizeof spt[0] * sbi.NumberProcessors, NULL)) + != STATUS_SUCCESS) { + DEBUG(D_load) + debug_printf("Perf: NtQuerySystemInformation: %u (Windows)\n", + RtlNtStatusToDosError(ret)); + } + else { + int i; + for (i = 0; i < sbi.NumberProcessors; i++) { + *Time100nsPtr += spt[i].KernelTime.QuadPart;; + *Time100nsPtr += spt[i].UserTime.QuadPart; + *IdleCountPtr += spt[i].IdleTime.QuadPart; + } + return TRUE; + } + return FALSE; +} + +/***************************************************************** + * + InitLoadAvg() + Initialize the cygwin_load.perf structure. + and set cygwin_load.perf->Flag to TRUE if successful. + This is called the first time os_getloadavg is called + *****************************************************************/ +static void InitLoadAvg(cygwin_perf_t *this) +{ + BOOL success = TRUE; + + /* Get perf frequency and counter */ + QueryPerformanceFrequency((LARGE_INTEGER *)& this->PerfFreq); + QueryPerformanceCounter((LARGE_INTEGER *)& this->LastCounter); + + /* Get initial values for Time100ns and IdleCount */ + success = success + && ReadStat( & this->Time100ns, + & this->IdleCount); + /* If success, set the Load to 0, else to -1 */ + if (success) this->LastLoad = 0; + else { + log_write(0, LOG_MAIN, "Cannot obtain Load Average"); + this->LastLoad = -1; + } +} + + +/***************************************************************** + * + os_getloadavg() + + Return -1 if not available; + Return the previous value if less than AVERAGING sec old. + else return the processor load on a [0 - 1000] scale. + + The first time we are called we initialize the counts + and return 0 or -1. + The initial load cannot be measured as we use the processor 100% +*****************************************************************/ +static SECURITY_ATTRIBUTES sa = {sizeof (SECURITY_ATTRIBUTES), NULL, TRUE}; +#define AVERAGING 10 + +int os_getloadavg() +{ + unsigned long long Time100ns, IdleCount, CurrCounter; + int value; + pid_t newpid; + + /* New process. + Reload the dlls and the file mapping */ + if ((newpid = getpid()) != cygwin_load.pid) { + BOOL new; + cygwin_load.pid = newpid; + + if (!LoadNtdll()) { + log_write(0, LOG_MAIN, "Cannot obtain Load Average"); + cygwin_load.perf = NULL; + return -1; + } + + if ((new = !cygwin_load.handle)) { + cygwin_load.handle = CreateFileMapping (INVALID_HANDLE_VALUE, &sa, PAGE_READWRITE, + 0, sizeof(cygwin_perf_t), NULL); + DEBUG(D_load) + debug_printf("Perf: CreateFileMapping: handle %p\n", (void *) cygwin_load.handle); + } + cygwin_load.perf = (cygwin_perf_t *) MapViewOfFile (cygwin_load.handle, + FILE_MAP_READ | FILE_MAP_WRITE, 0, 0, 0); + DEBUG(D_load) + debug_printf("Perf: MapViewOfFile: addr %p\n", (void *) cygwin_load.perf); + if (new && cygwin_load.perf) + InitLoadAvg(cygwin_load.perf); + } + + /* Check if initialized OK */ + if (!cygwin_load.perf || cygwin_load.perf->LastLoad < 0) + return -1; + + /* If we cannot get the lock, we return 0. + This is to prevent any lock-up possibility. + Finding a lock busy is unlikely, and giving up only + results in an immediate delivery .*/ + + if (InterlockedCompareExchange(&cygwin_load.perf->Lock, 1, 0)) { + DEBUG(D_load) + debug_printf("Perf: Lock busy\n"); + return 0; + } + + /* Get the current time (PerfCounter) */ + QueryPerformanceCounter((LARGE_INTEGER *)& CurrCounter); + /* Calls closer than AVERAGING sec apart use the previous value */ + if (CurrCounter - cygwin_load.perf->LastCounter > + AVERAGING * cygwin_load.perf->PerfFreq) { + /* Get Time100ns and IdleCount */ + if (ReadStat( & Time100ns, & IdleCount)) { /* Success */ + /* Return processor load on 1000 scale */ + value = 1000 - ((1000 * (IdleCount - cygwin_load.perf->IdleCount)) / + (Time100ns - cygwin_load.perf->Time100ns)); + cygwin_load.perf->Time100ns = Time100ns; + cygwin_load.perf->IdleCount = IdleCount; + cygwin_load.perf->LastCounter = CurrCounter; + cygwin_load.perf->LastLoad = value; + DEBUG(D_load) + debug_printf("Perf: New load average %d\n", value); + } + else { /* Something bad happened. + Refuse to measure the load anymore + but don't bother releasing the buffer */ + log_write(0, LOG_MAIN, "Cannot obtain Load Average"); + cygwin_load.perf->LastLoad = -1; + } + } + else + DEBUG(D_load) + debug_printf("Perf: Old load average %d\n", cygwin_load.perf->LastLoad); + cygwin_load.perf->Lock = 0; + return cygwin_load.perf->LastLoad; +} +#endif /* OS_LOAD_AVERAGE */ +#endif /* COMPILE_UTILITY */