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Diffstat (limited to 'daemons/execd/remoted_pidone.c')
| -rw-r--r-- | daemons/execd/remoted_pidone.c | 298 |
1 files changed, 298 insertions, 0 deletions
diff --git a/daemons/execd/remoted_pidone.c b/daemons/execd/remoted_pidone.c new file mode 100644 index 0000000..4f914eb --- /dev/null +++ b/daemons/execd/remoted_pidone.c @@ -0,0 +1,298 @@ +/* + * Copyright 2017-2020 the Pacemaker project contributors + * + * The version control history for this file may have further details. + * + * This source code is licensed under the GNU Lesser General Public License + * version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY. + */ + +#include <crm_internal.h> + +#include <stdio.h> +#include <ctype.h> +#include <stdlib.h> +#include <signal.h> +#include <unistd.h> +#include <sys/types.h> +#include <sys/wait.h> + +#include <crm/crm.h> +#include "pacemaker-execd.h" + +static pid_t main_pid = 0; + +static void +sigdone(void) +{ + exit(CRM_EX_OK); +} + +static void +sigreap(void) +{ + pid_t pid = 0; + int status; + + do { + /* + * Opinions seem to differ as to what to put here: + * -1, any child process + * 0, any child process whose process group ID is equal to that of the calling process + */ + pid = waitpid(-1, &status, WNOHANG); + if (pid == main_pid) { + /* Exit when pacemaker-remote exits and use the same return code */ + if (WIFEXITED(status)) { + exit(WEXITSTATUS(status)); + } + exit(CRM_EX_ERROR); + } + } while (pid > 0); +} + +static struct { + int sig; + void (*handler)(void); +} sigmap[] = { + { SIGCHLD, sigreap }, + { SIGINT, sigdone }, +}; + +/*! + * \internal + * \brief Check a line of text for a valid environment variable name + * + * \param[in] line Text to check + * \param[out] first First character of valid name if found, NULL otherwise + * \param[out] last Last character of valid name if found, NULL otherwise + * + * \return TRUE if valid name found, FALSE otherwise + * \note It's reasonable to impose limitations on environment variable names + * beyond what C or setenv() does: We only allow names that contain only + * [a-zA-Z0-9_] characters and do not start with a digit. + */ +static bool +find_env_var_name(char *line, char **first, char **last) +{ + // Skip leading whitespace + *first = line; + while (isspace(**first)) { + ++*first; + } + + if (isalpha(**first) || (**first == '_')) { // Valid first character + *last = *first; + while (isalnum(*(*last + 1)) || (*(*last + 1) == '_')) { + ++*last; + } + return TRUE; + } + + *first = *last = NULL; + return FALSE; +} + +static void +load_env_vars(const char *filename) +{ + /* We haven't forked or initialized logging yet, so don't leave any file + * descriptors open, and don't log -- silently ignore errors. + */ + FILE *fp = fopen(filename, "r"); + + if (fp != NULL) { + char line[LINE_MAX] = { '\0', }; + + while (fgets(line, LINE_MAX, fp) != NULL) { + char *name = NULL; + char *end = NULL; + char *value = NULL; + char *quote = NULL; + + // Look for valid name immediately followed by equals sign + if (find_env_var_name(line, &name, &end) && (*++end == '=')) { + + // Null-terminate name, and advance beyond equals sign + *end++ = '\0'; + + // Check whether value is quoted + if ((*end == '\'') || (*end == '"')) { + quote = end++; + } + value = end; + + if (quote) { + /* Value is remaining characters up to next non-backslashed + * matching quote character. + */ + while (((*end != *quote) || (*(end - 1) == '\\')) + && (*end != '\0')) { + end++; + } + if (*end == *quote) { + // Null-terminate value, and advance beyond close quote + *end++ = '\0'; + } else { + // Matching closing quote wasn't found + value = NULL; + } + + } else { + /* Value is remaining characters up to next non-backslashed + * whitespace. + */ + while ((!isspace(*end) || (*(end - 1) == '\\')) + && (*end != '\0')) { + ++end; + } + + if (end == (line + LINE_MAX - 1)) { + // Line was too long + value = NULL; + } + // Do NOT null-terminate value (yet) + } + + /* We have a valid name and value, and end is now the character + * after the closing quote or the first whitespace after the + * unquoted value. Make sure the rest of the line is just + * whitespace or a comment. + */ + if (value) { + char *value_end = end; + + while (isspace(*end) && (*end != '\n')) { + ++end; + } + if ((*end == '\n') || (*end == '#')) { + if (quote == NULL) { + // Now we can null-terminate an unquoted value + *value_end = '\0'; + } + + // Don't overwrite (bundle options take precedence) + setenv(name, value, 0); + + } else { + value = NULL; + } + } + } + + if ((value == NULL) && (strchr(line, '\n') == NULL)) { + // Eat remainder of line beyond LINE_MAX + if (fscanf(fp, "%*[^\n]\n") == EOF) { + value = NULL; // Don't care, make compiler happy + } + } + } + fclose(fp); + } +} + +void +remoted_spawn_pidone(int argc, char **argv, char **envp) +{ + sigset_t set; + + /* This environment variable exists for two purposes: + * - For testing, setting it to "full" enables full PID 1 behavior even + * when PID is not 1 + * - Setting to "vars" enables just the loading of environment variables + * from /etc/pacemaker/pcmk-init.env, which could be useful for testing or + * containers with a custom PID 1 script that launches pacemaker-remoted. + */ + const char *pid1 = (getpid() == 1)? "full" : getenv("PCMK_remote_pid1"); + + if (pid1 == NULL) { + return; + } + + /* When a container is launched, it may be given specific environment + * variables, which for Pacemaker bundles are given in the bundle + * configuration. However, that does not allow for host-specific values. + * To allow for that, look for a special file containing a shell-like syntax + * of name/value pairs, and export those into the environment. + */ + load_env_vars("/etc/pacemaker/pcmk-init.env"); + + if (strcmp(pid1, "full")) { + return; + } + + /* Containers can be expected to have /var/log, but they may not have + * /var/log/pacemaker, so use a different default if no value has been + * explicitly configured in the container's environment. + */ + if (pcmk__env_option(PCMK__ENV_LOGFILE) == NULL) { + pcmk__set_env_option(PCMK__ENV_LOGFILE, "/var/log/pcmk-init.log"); + } + + sigfillset(&set); + sigprocmask(SIG_BLOCK, &set, 0); + + main_pid = fork(); + switch (main_pid) { + case 0: + sigprocmask(SIG_UNBLOCK, &set, NULL); + setsid(); + setpgid(0, 0); + + // Child remains as pacemaker-remoted + return; + case -1: + perror("fork"); + } + + /* Parent becomes the reaper of zombie processes */ + /* Safe to initialize logging now if needed */ + +# ifdef HAVE_PROGNAME + /* Differentiate ourselves in the 'ps' output */ + { + char *p; + int i, maxlen; + char *LastArgv = NULL; + const char *name = "pcmk-init"; + + for (i = 0; i < argc; i++) { + if (!i || (LastArgv + 1 == argv[i])) + LastArgv = argv[i] + strlen(argv[i]); + } + + for (i = 0; envp[i] != NULL; i++) { + if ((LastArgv + 1) == envp[i]) { + LastArgv = envp[i] + strlen(envp[i]); + } + } + + maxlen = (LastArgv - argv[0]) - 2; + + i = strlen(name); + + /* We can overwrite individual argv[] arguments */ + snprintf(argv[0], maxlen, "%s", name); + + /* Now zero out everything else */ + p = &argv[0][i]; + while (p < LastArgv) { + *p++ = '\0'; + } + argv[1] = NULL; + } +# endif // HAVE_PROGNAME + + while (1) { + int sig; + size_t i; + + sigwait(&set, &sig); + for (i = 0; i < PCMK__NELEM(sigmap); i++) { + if (sigmap[i].sig == sig) { + sigmap[i].handler(); + break; + } + } + } +} |