From: =?utf-8?q?Christian_G=C3=B6ttsche?= Date: Fri, 24 Jul 2020 16:01:15 +0200 Subject: chkwtmp Minor fixes to avoid compiler warnings and overflows. a) use strncpy not memcopy when setting wtmpfile From: =?utf-8?q?Christian_G=C3=B6ttsche?= Date: Fri, 24 Jul 2020 16:01:15 +0200 b) include stdlib.h From: Giuseppe Iuculano Date: Sun, 9 Jul 2017 18:42:55 +0200 Items c-g from richard.lewis.debian@googlemail.com, Nov 2024 c) chkwtmp: fix compilation errors and indentation: declare args of printit(), fix indentation (tabs) and remove trailing whitespace d) Fix arg parsing and encoding - arg passing code should not assume the file is 127 bytes long. This could actually read bits of envp into wtmpfile. - Fix accents in comment to be valid utf8 e) Ensure return code is not too large - should be 0..255, not an arbitrary int. f) Remove duplicate #ifdefs g) Do not silently do nothing on an unsupported platform Forwarded: yes (Forwarded by email: 21 Dec 2024) --- chkwtmp.c | 41 +++++++++++++++++++---------------------- 1 file changed, 19 insertions(+), 22 deletions(-) diff --git a/chkwtmp.c b/chkwtmp.c index c207721..66515ba 100644 --- a/chkwtmp.c +++ b/chkwtmp.c @@ -15,14 +15,16 @@ Nelson Murilo, nmurilo@gmail.com 07/08/04 - fix del counter value (Thanks to Dietrich Raisin) Nelson Murilo, nmurilo@gmail.com - 09/12/05 - fix Segfault (Thanks to Jérémie Andréi) + 09/12/05 - fix Segfault (Thanks to Jérémie Andréi) Nelson Murilo, nmurilo@gmail.com */ -#if __FreeBSD__ > 9 -int main () { return 0; } -#else #include + +#if __FreeBSD__ > 9 +int main (void){ fprintf(stderr,"Unsupported operating system\n"); return 1; } +#else + #include #include #include @@ -33,20 +35,15 @@ int main () { return 0; } #ifdef SOLARIS2 #include #endif +#include -#ifdef __FreeBSD__ -#define WTMP_FILENAME "/var/log/wtmp" -#else #ifndef WTMP_FILENAME #define WTMP_FILENAME "/var/log/wtmp" #endif -#endif -void printit(counter, start, end) -int counter; -long start,end; +void printit(int counter, long start, long end) { - char buffer[30]; + char buffer[30]; printf("%d deletion(s) between ", counter); strncpy(buffer, ctime( (time_t *) &start), 30); @@ -55,27 +52,27 @@ long start,end; } -int main(int argc, char*argv[]) { +int main(int argc, char* argv[]) { int filehandle; struct utmp utmp_ent; struct timeval mytime; struct timezone dummy; long start_time, act_time; int del_counter, t_del; - char wtmpfile[128]; + char wtmpfile[128]; del_counter=t_del=0; start_time=0; gettimeofday(&mytime, &dummy); - act_time=mytime.tv_sec; - wtmpfile[127]='\0'; - memcpy(wtmpfile, WTMP_FILENAME, 127); - if ( argc == 3 && !memcmp("-f", argv[1], 2) && *argv[2]) - memcpy(wtmpfile, argv[2], 127); + act_time=mytime.tv_sec; + wtmpfile[127]='\0'; + strncpy(wtmpfile, WTMP_FILENAME, 127); + if ( argc == 3 && !memcmp("-f", argv[1], 2) && *argv[2] && strlen(argv[2])<127) + memcpy(wtmpfile, argv[2], strlen(argv[2])+1); if ((filehandle=open(wtmpfile,O_RDONLY)) < 0) { - fprintf(stderr, "unable to open wtmp-file %s\n", wtmpfile); + fprintf(stderr, "unable to open wtmp file %s\n", wtmpfile); return(2); } @@ -94,7 +91,7 @@ int main(int argc, char*argv[]) { } close(filehandle); if (del_counter) - printit(del_counter, start_time, act_time); - exit((int) t_del+del_counter); + printit(del_counter, start_time, act_time); + exit(t_del+del_counter > 0); // exit codes should be 0..255 } #endif