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Diffstat (limited to 'tests/tap/process.c')
| -rw-r--r-- | tests/tap/process.c | 532 |
1 files changed, 532 insertions, 0 deletions
diff --git a/tests/tap/process.c b/tests/tap/process.c new file mode 100644 index 000000000000..2f797f8f7567 --- /dev/null +++ b/tests/tap/process.c @@ -0,0 +1,532 @@ +/* + * Utility functions for tests that use subprocesses. + * + * Provides utility functions for subprocess manipulation. Specifically, + * provides a function, run_setup, which runs a command and bails if it fails, + * using its error message as the bail output, and is_function_output, which + * runs a function in a subprocess and checks its output and exit status + * against expected values. + * + * Requires an Autoconf probe for sys/select.h and a replacement for a missing + * mkstemp. + * + * The canonical version of this file is maintained in the rra-c-util package, + * which can be found at <https://www.eyrie.org/~eagle/software/rra-c-util/>. + * + * Written by Russ Allbery <eagle@eyrie.org> + * Copyright 2002, 2004-2005, 2013, 2016-2017 Russ Allbery <eagle@eyrie.org> + * Copyright 2009-2011, 2013-2014 + * The Board of Trustees of the Leland Stanford Junior University + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the "Software"), + * to deal in the Software without restriction, including without limitation + * the rights to use, copy, modify, merge, publish, distribute, sublicense, + * and/or sell copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER + * DEALINGS IN THE SOFTWARE. + * + * SPDX-License-Identifier: MIT + */ + +#include <config.h> +#include <portable/system.h> + +#include <errno.h> +#include <fcntl.h> +#include <signal.h> +#ifdef HAVE_SYS_SELECT_H +# include <sys/select.h> +#endif +#include <sys/stat.h> +#ifdef HAVE_SYS_TIME_H +# include <sys/time.h> +#endif +#include <sys/wait.h> +#include <time.h> + +#include <tests/tap/basic.h> +#include <tests/tap/process.h> +#include <tests/tap/string.h> + +/* May be defined by the build system. */ +#ifndef PATH_FAKEROOT +# define PATH_FAKEROOT "" +#endif + +/* How long to wait for the process to start in seconds. */ +#define PROCESS_WAIT 10 + +/* + * Used to store information about a background process. This contains + * everything required to stop the process and clean up after it. + */ +struct process { + pid_t pid; /* PID of child process */ + char *pidfile; /* PID file to delete on process stop */ + char *tmpdir; /* Temporary directory for log file */ + char *logfile; /* Log file of process output */ + bool is_child; /* Whether we can waitpid for process */ + struct process *next; /* Next process in global list */ +}; + +/* + * Global list of started processes, which will be cleaned up automatically on + * program exit if they haven't been explicitly stopped with process_stop + * prior to that point. + */ +static struct process *processes = NULL; + + +/* + * Given a function, an expected exit status, and expected output, runs that + * function in a subprocess, capturing stdout and stderr via a pipe, and + * returns the function output in newly allocated memory. Also captures the + * process exit status. + */ +static void +run_child_function(test_function_type function, void *data, int *status, + char **output) +{ + int fds[2]; + pid_t child; + char *buf; + ssize_t count, ret, buflen; + int rval; + + /* Flush stdout before we start to avoid odd forking issues. */ + fflush(stdout); + + /* Set up the pipe and call the function, collecting its output. */ + if (pipe(fds) == -1) + sysbail("can't create pipe"); + child = fork(); + if (child == (pid_t) -1) { + sysbail("can't fork"); + } else if (child == 0) { + /* In child. Set up our stdout and stderr. */ + close(fds[0]); + if (dup2(fds[1], 1) == -1) + _exit(255); + if (dup2(fds[1], 2) == -1) + _exit(255); + + /* Now, run the function and exit successfully if it returns. */ + (*function)(data); + fflush(stdout); + _exit(0); + } else { + /* + * In the parent; close the extra file descriptor, read the output if + * any, and then collect the exit status. + */ + close(fds[1]); + buflen = BUFSIZ; + buf = bmalloc(buflen); + count = 0; + do { + ret = read(fds[0], buf + count, buflen - count - 1); + if (SSIZE_MAX - count <= ret) + bail("maximum output size exceeded in run_child_function"); + if (ret > 0) + count += ret; + if (count >= buflen - 1) { + buflen += BUFSIZ; + buf = brealloc(buf, buflen); + } + } while (ret > 0); + buf[count] = '\0'; + if (waitpid(child, &rval, 0) == (pid_t) -1) + sysbail("waitpid failed"); + close(fds[0]); + } + + /* Store the output and return. */ + *status = rval; + *output = buf; +} + + +/* + * Given a function, data to pass to that function, an expected exit status, + * and expected output, runs that function in a subprocess, capturing stdout + * and stderr via a pipe, and compare the combination of stdout and stderr + * with the expected output and the exit status with the expected status. + * Expects the function to always exit (not die from a signal). + */ +void +is_function_output(test_function_type function, void *data, int status, + const char *output, const char *format, ...) +{ + char *buf, *msg; + int rval; + va_list args; + + run_child_function(function, data, &rval, &buf); + + /* Now, check the results against what we expected. */ + va_start(args, format); + bvasprintf(&msg, format, args); + va_end(args); + ok(WIFEXITED(rval), "%s (exited)", msg); + is_int(status, WEXITSTATUS(rval), "%s (status)", msg); + is_string(output, buf, "%s (output)", msg); + free(buf); + free(msg); +} + + +/* + * A helper function for run_setup. This is a function to run an external + * command, suitable for passing into run_child_function. The expected + * argument must be an argv array, with argv[0] being the command to run. + */ +static void +exec_command(void *data) +{ + char *const *argv = data; + + execvp(argv[0], argv); +} + + +/* + * Given a command expressed as an argv struct, with argv[0] the name or path + * to the command, run that command. If it exits with a non-zero status, use + * the part of its output up to the first newline as the error message when + * calling bail. + */ +void +run_setup(const char *const argv[]) +{ + char *output, *p; + int status; + + run_child_function(exec_command, (void *) argv, &status, &output); + if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { + p = strchr(output, '\n'); + if (p != NULL) + *p = '\0'; + if (output[0] != '\0') + bail("%s", output); + else + bail("setup command failed with no output"); + } + free(output); +} + + +/* + * Free the resources associated with tracking a process, without doing + * anything to the process. This is kept separate so that we can free + * resources during shutdown in a non-primary process. + */ +static void +process_free(struct process *process) +{ + struct process **prev; + + /* Do nothing if called with a NULL argument. */ + if (process == NULL) + return; + + /* Remove the process from the global list. */ + prev = &processes; + while (*prev != NULL && *prev != process) + prev = &(*prev)->next; + if (*prev == process) + *prev = process->next; + + /* Free resources. */ + free(process->pidfile); + free(process->logfile); + test_tmpdir_free(process->tmpdir); + free(process); +} + + +/* + * Kill a process and wait for it to exit. Returns the status of the process. + * Calls bail on a system failure or a failure of the process to exit. + * + * We are quite aggressive with error reporting here because child processes + * that don't exit or that don't exist often indicate some form of test + * failure. + */ +static int +process_kill(struct process *process) +{ + int result, i; + int status = -1; + struct timeval tv; + unsigned long pid = process->pid; + + /* If the process is not a child, just kill it and hope. */ + if (!process->is_child) { + if (kill(process->pid, SIGTERM) < 0 && errno != ESRCH) + sysbail("cannot send SIGTERM to process %lu", pid); + return 0; + } + + /* Check if the process has already exited. */ + result = waitpid(process->pid, &status, WNOHANG); + if (result < 0) + sysbail("cannot wait for child process %lu", pid); + else if (result > 0) + return status; + + /* + * Kill the process and wait for it to exit. I don't want to go to the + * work of setting up a SIGCHLD handler or a full event loop here, so we + * effectively poll every tenth of a second for process exit (and + * hopefully faster when it does since the SIGCHLD may interrupt our + * select, although we're racing with it. + */ + if (kill(process->pid, SIGTERM) < 0 && errno != ESRCH) + sysbail("cannot send SIGTERM to child process %lu", pid); + for (i = 0; i < PROCESS_WAIT * 10; i++) { + tv.tv_sec = 0; + tv.tv_usec = 100000; + select(0, NULL, NULL, NULL, &tv); + result = waitpid(process->pid, &status, WNOHANG); + if (result < 0) + sysbail("cannot wait for child process %lu", pid); + else if (result > 0) + return status; + } + + /* The process still hasn't exited. Bail. */ + bail("child process %lu did not exit on SIGTERM", pid); + + /* Not reached, but some compilers may get confused. */ + return status; +} + + +/* + * Stop a particular process given its process struct. This kills the + * process, waits for it to exit if possible (giving it at most five seconds), + * and then removes it from the global processes struct so that it isn't + * stopped again during global shutdown. + */ +void +process_stop(struct process *process) +{ + int status; + unsigned long pid = process->pid; + + /* Stop the process. */ + status = process_kill(process); + + /* Call diag to flush logs as well as provide exit status. */ + if (process->is_child) + diag("stopped process %lu (exit status %d)", pid, status); + else + diag("stopped process %lu", pid); + + /* Remove the log and PID file. */ + diag_file_remove(process->logfile); + unlink(process->pidfile); + unlink(process->logfile); + + /* Free resources. */ + process_free(process); +} + + +/* + * Stop all running processes. This is called as a cleanup handler during + * process shutdown. The first argument, which says whether the test was + * successful, is ignored, since the same actions should be performed + * regardless. The second argument says whether this is the primary process, + * in which case we do the full shutdown. Otherwise, we only free resources + * but don't stop the process. + */ +static void +process_stop_all(int success UNUSED, int primary) +{ + while (processes != NULL) { + if (primary) + process_stop(processes); + else + process_free(processes); + } +} + + +/* + * Read the PID of a process from a file. This is necessary when running + * under fakeroot to get the actual PID of the remctld process. + */ +static pid_t +read_pidfile(const char *path) +{ + FILE *file; + char buffer[BUFSIZ]; + long pid; + + file = fopen(path, "r"); + if (file == NULL) + sysbail("cannot open %s", path); + if (fgets(buffer, sizeof(buffer), file) == NULL) + sysbail("cannot read from %s", path); + fclose(file); + pid = strtol(buffer, NULL, 10); + if (pid <= 0) + bail("cannot read PID from %s", path); + return (pid_t) pid; +} + + +/* + * Start a process and return its status information. The status information + * is also stored in the global processes linked list so that it can be + * stopped automatically on program exit. + * + * The boolean argument says whether to start the process under fakeroot. If + * true, PATH_FAKEROOT must be defined, generally by Autoconf. If it's not + * found, call skip_all. + * + * This is a helper function for process_start and process_start_fakeroot. + */ +static struct process * +process_start_internal(const char *const argv[], const char *pidfile, + bool fakeroot) +{ + size_t i; + int log_fd; + const char *name; + struct timeval tv; + struct process *process; + const char **fakeroot_argv = NULL; + const char *path_fakeroot = PATH_FAKEROOT; + + /* Check prerequisites. */ + if (fakeroot && path_fakeroot[0] == '\0') + skip_all("fakeroot not found"); + + /* Create the process struct and log file. */ + process = bcalloc(1, sizeof(struct process)); + process->pidfile = bstrdup(pidfile); + process->tmpdir = test_tmpdir(); + name = strrchr(argv[0], '/'); + if (name != NULL) + name++; + else + name = argv[0]; + basprintf(&process->logfile, "%s/%s.log.XXXXXX", process->tmpdir, name); + log_fd = mkstemp(process->logfile); + if (log_fd < 0) + sysbail("cannot create log file for %s", argv[0]); + + /* If using fakeroot, rewrite argv accordingly. */ + if (fakeroot) { + for (i = 0; argv[i] != NULL; i++) + ; + fakeroot_argv = bcalloc(2 + i + 1, sizeof(const char *)); + fakeroot_argv[0] = path_fakeroot; + fakeroot_argv[1] = "--"; + for (i = 0; argv[i] != NULL; i++) + fakeroot_argv[i + 2] = argv[i]; + fakeroot_argv[i + 2] = NULL; + argv = fakeroot_argv; + } + + /* + * Fork off the child process, redirect its standard output and standard + * error to the log file, and then exec the program. + */ + process->pid = fork(); + if (process->pid < 0) + sysbail("fork failed"); + else if (process->pid == 0) { + if (dup2(log_fd, STDOUT_FILENO) < 0) + sysbail("cannot redirect standard output"); + if (dup2(log_fd, STDERR_FILENO) < 0) + sysbail("cannot redirect standard error"); + close(log_fd); + if (execv(argv[0], (char *const *) argv) < 0) + sysbail("exec of %s failed", argv[0]); + } + close(log_fd); + free(fakeroot_argv); + + /* + * In the parent. Wait for the child to start by watching for the PID + * file to appear in 100ms intervals. + */ + for (i = 0; i < PROCESS_WAIT * 10 && access(pidfile, F_OK) != 0; i++) { + tv.tv_sec = 0; + tv.tv_usec = 100000; + select(0, NULL, NULL, NULL, &tv); + } + + /* + * If the PID file still hasn't appeared after ten seconds, attempt to + * kill the process and then bail. + */ + if (access(pidfile, F_OK) != 0) { + kill(process->pid, SIGTERM); + alarm(5); + waitpid(process->pid, NULL, 0); + alarm(0); + bail("cannot start %s", argv[0]); + } + + /* + * Read the PID back from the PID file. This usually isn't necessary for + * non-forking daemons, but always doing this makes this function general, + * and it's required when running under fakeroot. + */ + if (fakeroot) + process->pid = read_pidfile(pidfile); + process->is_child = !fakeroot; + + /* Register the log file as a source of diag messages. */ + diag_file_add(process->logfile); + + /* + * Add the process to our global list and set our cleanup handler if this + * is the first process we started. + */ + if (processes == NULL) + test_cleanup_register(process_stop_all); + process->next = processes; + processes = process; + + /* All done. */ + return process; +} + + +/* + * Start a process and return the opaque process struct. The process must + * create pidfile with its PID when startup is complete. + */ +struct process * +process_start(const char *const argv[], const char *pidfile) +{ + return process_start_internal(argv, pidfile, false); +} + + +/* + * Start a process under fakeroot and return the opaque process struct. If + * fakeroot is not available, calls skip_all. The process must create pidfile + * with its PID when startup is complete. + */ +struct process * +process_start_fakeroot(const char *const argv[], const char *pidfile) +{ + return process_start_internal(argv, pidfile, true); +} |