diff options
| -rw-r--r-- | pw/pw_log.c | 92 |
1 files changed, 71 insertions, 21 deletions
diff --git a/pw/pw_log.c b/pw/pw_log.c index 29038d9..fe8d803 100644 --- a/pw/pw_log.c +++ b/pw/pw_log.c @@ -29,40 +29,90 @@ static const char rcsid[] = "$FreeBSD$"; #endif /* not lint */ +#include <ctype.h> +#include <err.h> #include <fcntl.h> #include <string.h> #include <stdarg.h> #include "pw.h" -static FILE *logfile = NULL; +static FILE *logfile = NULL; void pw_log(struct userconf * cnf, int mode, int which, char const * fmt,...) { - if (cnf->logfile && *cnf->logfile) { - if (logfile == NULL) { /* With umask==0 we need to control file access modes on create */ - int fd = open(cnf->logfile, O_WRONLY | O_CREAT | O_APPEND, 0600); + va_list argp; + time_t now; + const char *cp, *name; + struct tm *t; + int fd, i, rlen; + char nfmt[256], sname[32]; - if (fd != -1) - logfile = fdopen(fd, "a"); + if (cnf->logfile == NULL || cnf->logfile[0] == '\0') { + return; + } + + if (logfile == NULL) { + /* With umask==0 we need to control file access modes on create */ + fd = open(cnf->logfile, O_WRONLY | O_CREAT | O_APPEND, 0600); + if (fd == -1) { + return; + } + logfile = fdopen(fd, "a"); + if (logfile == NULL) { + return; } - if (logfile != NULL) { - va_list argp; - time_t now = time(NULL); - struct tm *t = localtime(&now); - char nfmt[256]; - const char *name; + } - if ((name = getenv("LOGNAME")) == NULL && (name = getenv("USER")) == NULL) - name = "unknown"; - /* ISO 8601 International Standard Date format */ - strftime(nfmt, sizeof nfmt, "%Y-%m-%d %T ", t); - sprintf(nfmt + strlen(nfmt), "[%s:%s%s] %s\n", name, Which[which], Modes[mode], fmt); - va_start(argp, fmt); - vfprintf(logfile, nfmt, argp); - va_end(argp); - fflush(logfile); + if ((name = getenv("LOGNAME")) == NULL && + (name = getenv("USER")) == NULL) { + strcpy(sname, "unknown"); + } else { + /* + * Since "name" will be embedded in a printf-like format, + * we must sanitize it: + * + * Limit its length so other information in the message + * is not truncated + * + * Squeeze out embedded whitespace for the benefit of + * log file parsers + * + * Escape embedded % characters with another % + */ + for (i = 0, cp = name; + *cp != '\0' && i < (int)sizeof(sname) - 1; cp++) { + if (*cp == '%') { + if (i < (int)sizeof(sname) - 2) { + sname[i++] = '%'; + sname[i++] = '%'; + } else { + break; + } + } else if (!isspace(*cp)) { + sname[i++] = *cp; + } /* else do nothing */ + } + if (i == 0) { + strcpy(sname, "unknown"); + } else { + sname[i] = '\0'; } } + now = time(NULL); + t = localtime(&now); + /* ISO 8601 International Standard Date format */ + strftime(nfmt, sizeof nfmt, "%Y-%m-%d %T ", t); + rlen = sizeof(nfmt) - strlen(nfmt); + if (rlen <= 0 || snprintf(nfmt + strlen(nfmt), rlen, + "[%s:%s%s] %s\n", sname, Which[which], Modes[mode], + fmt) >= rlen) { + warnx("log format overflow, user name=%s", sname); + } else { + va_start(argp, fmt); + vfprintf(logfile, nfmt, argp); + va_end(argp); + fflush(logfile); + } } |