diff options
Diffstat (limited to 'modules/pam_filter/upperLOWER/upperLOWER.c')
-rw-r--r-- | modules/pam_filter/upperLOWER/upperLOWER.c | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/modules/pam_filter/upperLOWER/upperLOWER.c b/modules/pam_filter/upperLOWER/upperLOWER.c new file mode 100644 index 0000000..25e70a5 --- /dev/null +++ b/modules/pam_filter/upperLOWER/upperLOWER.c @@ -0,0 +1,141 @@ +/* + * This is a sample filter program, for use with pam_filter (a module + * provided with Linux-PAM). This filter simply transposes upper and + * lower case letters, it is intended for demonstration purposes and + * it serves no purpose other than to annoy the user... + */ + +#include "config.h" + +#include <ctype.h> +#include <stdio.h> +#include <stdlib.h> +#include <syslog.h> +#include <sys/time.h> +#include <sys/types.h> +#include <unistd.h> + +#include "pam_filter.h" +#include <security/pam_modutil.h> + +/* ---------------------------------------------------------------- */ + +static void do_transpose(char *buffer,int len) +{ + int i; + for (i=0; i<len; ++i) { + if (islower(buffer[i])) { + buffer[i] = toupper(buffer[i]); + } else { + buffer[i] = tolower(buffer[i]); + } + } +} + +extern char **environ; + +int main(int argc, char **argv UNUSED) +{ + char buffer[BUFSIZ]; + fd_set readers; + void (*before_user)(char *,int); + void (*before_app)(char *,int); + + openlog("upperLOWER", LOG_CONS|LOG_PID, LOG_AUTHPRIV); + +#ifdef DEBUG + { + int i; + + fprintf(stderr,"environment :[\r\n"); + for (i=0; environ[i]; ++i) { + fprintf(stderr,"-> %s\r\n",environ[i]); + } + fprintf(stderr,"]: end\r\n"); + } +#endif + + if (argc != 1) { +#ifdef DEBUG + fprintf(stderr,"filter invoked as conventional executable\n"); +#else + syslog(LOG_ERR, "filter invoked as conventional executable"); +#endif + exit(1); + } + + before_user = before_app = do_transpose; /* assign filter functions */ + + /* enter a loop that deals with the input and output of the + user.. passing it to and from the application */ + + FD_ZERO(&readers); /* initialize reading mask */ + + for (;;) { + + FD_SET(APPOUT_FILENO, &readers); /* wake for output */ + FD_SET(APPERR_FILENO, &readers); /* wake for error */ + FD_SET(STDIN_FILENO, &readers); /* wake for input */ + + if ( select(APPTOP_FILE,&readers,NULL,NULL,NULL) < 0 ) { +#ifdef DEBUG + fprintf(stderr,"select failed\n"); +#else + syslog(LOG_WARNING,"select failed"); +#endif + break; + } + + /* application errors */ + + if ( FD_ISSET(APPERR_FILENO,&readers) ) { + int got = read(APPERR_FILENO, buffer, BUFSIZ); + if (got <= 0) { + break; + } else { + /* translate to give to real terminal */ + if (before_user != NULL) + before_user(buffer, got); + if (pam_modutil_write(STDERR_FILENO, buffer, got) != got ) { + syslog(LOG_WARNING,"couldn't write %d bytes?!",got); + break; + } + } + } else if ( FD_ISSET(APPOUT_FILENO,&readers) ) { /* app output */ + int got = read(APPOUT_FILENO, buffer, BUFSIZ); + if (got <= 0) { + break; + } else { + /* translate to give to real terminal */ + if (before_user != NULL) + before_user(buffer, got); + if (pam_modutil_write(STDOUT_FILENO, buffer, got) != got ) { + syslog(LOG_WARNING,"couldn't write %d bytes!?",got); + break; + } + } + } + + if ( FD_ISSET(STDIN_FILENO, &readers) ) { /* user input */ + int got = read(STDIN_FILENO, buffer, BUFSIZ); + if (got < 0) { + syslog(LOG_WARNING,"user input junked"); + break; + } else if (got) { + /* translate to give to application */ + if (before_app != NULL) + before_app(buffer, got); + if (pam_modutil_write(APPIN_FILENO, buffer, got) != got ) { + syslog(LOG_WARNING,"couldn't pass %d bytes!?",got); + break; + } + } else { + /* nothing received -- an error? */ + syslog(LOG_WARNING,"user input null?"); + break; + } + } + } + + exit(0); +} |