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Diffstat (limited to 'src/common/procmon.c')
| -rw-r--r-- | src/common/procmon.c | 336 |
1 files changed, 0 insertions, 336 deletions
diff --git a/src/common/procmon.c b/src/common/procmon.c deleted file mode 100644 index 6c2b3e71e5..0000000000 --- a/src/common/procmon.c +++ /dev/null @@ -1,336 +0,0 @@ -/* Copyright (c) 2011-2018, The Tor Project, Inc. */ -/* See LICENSE for licensing information */ - -/** - * \file procmon.c - * \brief Process-termination monitor functions - **/ - -#include "common/procmon.h" - -#include "lib/log/torlog.h" -#include "lib/log/util_bug.h" -#include "lib/log/win32err.h" -#include "lib/malloc/util_malloc.h" -#include "lib/string/parse_int.h" - -#ifdef HAVE_SIGNAL_H -#include <signal.h> -#endif -#ifdef HAVE_ERRNO_H -#include <errno.h> -#endif - -#ifdef _WIN32 -#include <winsock2.h> -#include <windows.h> -#endif - -#if (0 == SIZEOF_PID_T) && defined(_WIN32) -/* Windows does not define pid_t sometimes, but _getpid() returns an int. - * Everybody else needs to have a pid_t. */ -typedef int pid_t; -#define PID_T_FORMAT "%d" -#elif (SIZEOF_PID_T == SIZEOF_INT) || (SIZEOF_PID_T == SIZEOF_SHORT) -#define PID_T_FORMAT "%d" -#elif (SIZEOF_PID_T == SIZEOF_LONG) -#define PID_T_FORMAT "%ld" -#elif (SIZEOF_PID_T == 8) -#define PID_T_FORMAT "%"PRId64 -#else -#error Unknown: SIZEOF_PID_T -#endif /* (0 == SIZEOF_PID_T) && defined(_WIN32) || ... */ - -/* Define to 1 if process-termination monitors on this OS and Libevent - version must poll for process termination themselves. */ -#define PROCMON_POLLS 1 -/* Currently we need to poll in some way on all systems. */ - -#ifdef PROCMON_POLLS -static void tor_process_monitor_poll_cb(periodic_timer_t *ev, - void *procmon_); -#endif - -/* This struct may contain pointers into the original process - * specifier string, but it should *never* contain anything which - * needs to be freed. */ -/* DOCDOC parsed_process_specifier_t */ -struct parsed_process_specifier_t { - pid_t pid; -}; - -/** Parse the process specifier given in <b>process_spec</b> into - * *<b>ppspec</b>. Return 0 on success; return -1 and store an error - * message into *<b>msg</b> on failure. The caller must not free the - * returned error message. */ -static int -parse_process_specifier(const char *process_spec, - struct parsed_process_specifier_t *ppspec, - const char **msg) -{ - long pid_l; - int pid_ok = 0; - char *pspec_next; - - /* If we're lucky, long will turn out to be large enough to hold a - * PID everywhere that Tor runs. */ - pid_l = tor_parse_long(process_spec, 10, 1, LONG_MAX, &pid_ok, &pspec_next); - - /* Reserve room in the ‘process specifier’ for additional - * (platform-specific) identifying information beyond the PID, to - * make our process-existence checks a bit less racy in a future - * version. */ - if ((*pspec_next != 0) && (*pspec_next != ' ') && (*pspec_next != ':')) { - pid_ok = 0; - } - - ppspec->pid = (pid_t)(pid_l); - if (!pid_ok || (pid_l != (long)(ppspec->pid))) { - *msg = "invalid PID"; - goto err; - } - - return 0; - err: - return -1; -} - -/* DOCDOC tor_process_monitor_t */ -struct tor_process_monitor_t { - /** Log domain for warning messages. */ - log_domain_mask_t log_domain; - - /** All systems: The best we can do in general is poll for the - * process's existence by PID periodically, and hope that the kernel - * doesn't reassign the same PID to another process between our - * polls. */ - pid_t pid; - -#ifdef _WIN32 - /** Windows-only: Should we poll hproc? If false, poll pid - * instead. */ - int poll_hproc; - - /** Windows-only: Get a handle to the process (if possible) and - * periodically check whether the process we have a handle to has - * ended. */ - HANDLE hproc; - /* XXXX We should have Libevent watch hproc for us, - * if/when some version of Libevent can be told to do so. */ -#endif /* defined(_WIN32) */ - - /* XXXX On Linux, we can and should receive the 22nd - * (space-delimited) field (‘starttime’) of /proc/$PID/stat from the - * owning controller and store it, and poll once in a while to see - * whether it has changed -- if so, the kernel has *definitely* - * reassigned the owning controller's PID and we should exit. On - * FreeBSD, we can do the same trick using either the 8th - * space-delimited field of /proc/$PID/status on the seven FBSD - * systems whose admins have mounted procfs, or the start-time field - * of the process-information structure returned by kvmgetprocs() on - * any system. The latter is ickier. */ - - /* XXXX On FreeBSD (and possibly other kqueue systems), we can and - * should arrange to receive EVFILT_PROC NOTE_EXIT notifications for - * pid, so we don't have to do such a heavyweight poll operation in - * order to avoid the PID-reassignment race condition. (We would - * still need to poll our own kqueue periodically until some version - * of Libevent 2.x learns to receive these events for us.) */ - - /** A Libevent event structure, to either poll for the process's - * existence or receive a notification when the process ends. */ - periodic_timer_t *e; - - /** A callback to be called when the process ends. */ - tor_procmon_callback_t cb; - void *cb_arg; /**< A user-specified pointer to be passed to cb. */ -}; - -/** Verify that the process specifier given in <b>process_spec</b> is - * syntactically valid. Return 0 on success; return -1 and store an - * error message into *<b>msg</b> on failure. The caller must not - * free the returned error message. */ -int -tor_validate_process_specifier(const char *process_spec, - const char **msg) -{ - struct parsed_process_specifier_t ppspec; - - tor_assert(msg != NULL); - *msg = NULL; - - return parse_process_specifier(process_spec, &ppspec, msg); -} - -/* DOCDOC poll_interval_tv */ -static const struct timeval poll_interval_tv = {15, 0}; - -/** Create a process-termination monitor for the process specifier - * given in <b>process_spec</b>. Return a newly allocated - * tor_process_monitor_t on success; return NULL and store an error - * message into *<b>msg</b> on failure. The caller must not free - * the returned error message. - * - * When the monitored process terminates, call - * <b>cb</b>(<b>cb_arg</b>). - */ -tor_process_monitor_t * -tor_process_monitor_new(struct event_base *base, - const char *process_spec, - log_domain_mask_t log_domain, - tor_procmon_callback_t cb, void *cb_arg, - const char **msg) -{ - tor_process_monitor_t *procmon = tor_malloc_zero( - sizeof(tor_process_monitor_t)); - struct parsed_process_specifier_t ppspec; - - tor_assert(msg != NULL); - *msg = NULL; - - if (procmon == NULL) { - *msg = "out of memory"; - goto err; - } - - procmon->log_domain = log_domain; - - if (parse_process_specifier(process_spec, &ppspec, msg)) - goto err; - - procmon->pid = ppspec.pid; - -#ifdef _WIN32 - procmon->hproc = OpenProcess(PROCESS_QUERY_INFORMATION | SYNCHRONIZE, - FALSE, - procmon->pid); - - if (procmon->hproc != NULL) { - procmon->poll_hproc = 1; - log_info(procmon->log_domain, "Successfully opened handle to process " - PID_T_FORMAT"; " - "monitoring it.", - procmon->pid); - } else { - /* If we couldn't get a handle to the process, we'll try again the - * first time we poll. */ - log_info(procmon->log_domain, "Failed to open handle to process " - PID_T_FORMAT"; will " - "try again later.", - procmon->pid); - } -#endif /* defined(_WIN32) */ - - procmon->cb = cb; - procmon->cb_arg = cb_arg; - -#ifdef PROCMON_POLLS - procmon->e = periodic_timer_new(base, - &poll_interval_tv, - tor_process_monitor_poll_cb, procmon); -#else /* !(defined(PROCMON_POLLS)) */ -#error OOPS? -#endif /* defined(PROCMON_POLLS) */ - - return procmon; - err: - tor_process_monitor_free(procmon); - return NULL; -} - -#ifdef PROCMON_POLLS -/** Libevent callback to poll for the existence of the process - * monitored by <b>procmon_</b>. */ -static void -tor_process_monitor_poll_cb(periodic_timer_t *event, void *procmon_) -{ - (void)event; - tor_process_monitor_t *procmon = (tor_process_monitor_t *)(procmon_); - int its_dead_jim; - - tor_assert(procmon != NULL); - -#ifdef _WIN32 - if (procmon->poll_hproc) { - DWORD exit_code; - if (!GetExitCodeProcess(procmon->hproc, &exit_code)) { - char *errmsg = format_win32_error(GetLastError()); - log_warn(procmon->log_domain, "Error \"%s\" occurred while polling " - "handle for monitored process "PID_T_FORMAT"; assuming " - "it's dead.", - errmsg, procmon->pid); - tor_free(errmsg); - its_dead_jim = 1; - } else { - its_dead_jim = (exit_code != STILL_ACTIVE); - } - } else { - /* All we can do is try to open the process, and look at the error - * code if it fails again. */ - procmon->hproc = OpenProcess(PROCESS_QUERY_INFORMATION | SYNCHRONIZE, - FALSE, - procmon->pid); - - if (procmon->hproc != NULL) { - log_info(procmon->log_domain, "Successfully opened handle to monitored " - "process "PID_T_FORMAT".", - procmon->pid); - its_dead_jim = 0; - procmon->poll_hproc = 1; - } else { - DWORD err_code = GetLastError(); - char *errmsg = format_win32_error(err_code); - - /* When I tested OpenProcess's error codes on Windows 7, I - * received error code 5 (ERROR_ACCESS_DENIED) for PIDs of - * existing processes that I could not open and error code 87 - * (ERROR_INVALID_PARAMETER) for PIDs that were not in use. - * Since the nonexistent-process error code is sane, I'm going - * to assume that all errors other than ERROR_INVALID_PARAMETER - * mean that the process we are monitoring is still alive. */ - its_dead_jim = (err_code == ERROR_INVALID_PARAMETER); - - if (!its_dead_jim) - log_info(procmon->log_domain, "Failed to open handle to monitored " - "process "PID_T_FORMAT", and error code %lu (%s) is not " - "'invalid parameter' -- assuming the process is still alive.", - procmon->pid, - err_code, errmsg); - - tor_free(errmsg); - } - } -#else /* !(defined(_WIN32)) */ - /* Unix makes this part easy, if a bit racy. */ - its_dead_jim = kill(procmon->pid, 0); - its_dead_jim = its_dead_jim && (errno == ESRCH); -#endif /* defined(_WIN32) */ - - tor_log(its_dead_jim ? LOG_NOTICE : LOG_INFO, - procmon->log_domain, "Monitored process "PID_T_FORMAT" is %s.", - procmon->pid, - its_dead_jim ? "dead" : "still alive"); - - if (its_dead_jim) { - procmon->cb(procmon->cb_arg); - } -} -#endif /* defined(PROCMON_POLLS) */ - -/** Free the process-termination monitor <b>procmon</b>. */ -void -tor_process_monitor_free_(tor_process_monitor_t *procmon) -{ - if (procmon == NULL) - return; - -#ifdef _WIN32 - if (procmon->hproc != NULL) - CloseHandle(procmon->hproc); -#endif - - if (procmon->e != NULL) - periodic_timer_free(procmon->e); - - tor_free(procmon); -} |