svn commit: r348842 - head/usr.bin/tail

[Mariusz Zaborski]

Author: oshogbo
Date: Sun Jun  9 22:55:21 2019
New Revision: 348842
URL: https://svnweb.freebsd.org/changeset/base/348842

Log:
  tail: fix the checks if the file was rotated
  
  The freopen(3) was replaced with fileargs_open(3) and fclose(3).
  In the following function, we skip if the stream is standard in, so it is
  safe to do so.
  This also requires us to change the logic first to open the file and then
  check its status. The stat(2) is disallowed in capability mode.
  
  This commit unbrakes the -F option.
  The bug was introduced in the r348708.
  
  Reported by:	pho
  Tested by:	pho

Modified:
  head/usr.bin/tail/extern.h
  head/usr.bin/tail/forward.c
  head/usr.bin/tail/misc.c
  head/usr.bin/tail/read.c
  head/usr.bin/tail/reverse.c
  head/usr.bin/tail/tail.c

Modified: head/usr.bin/tail/extern.h
==============================================================================
--- head/usr.bin/tail/extern.h	Sun Jun  9 22:45:07 2019	(r348841)
+++ head/usr.bin/tail/extern.h	Sun Jun  9 22:55:21 2019	(r348842)
@@ -78,3 +78,4 @@ int maparound(struct mapinfo *, off_t);
 void printfn(const char *, int);
 
 extern int Fflag, fflag, qflag, rflag, rval, no_files;
+extern fileargs_t *fa;

Modified: head/usr.bin/tail/forward.c
==============================================================================
--- head/usr.bin/tail/forward.c	Sun Jun  9 22:45:07 2019	(r348841)
+++ head/usr.bin/tail/forward.c	Sun Jun  9 22:55:21 2019	(r348842)
@@ -57,6 +57,9 @@ static const char sccsid[] = "@(#)forward.c	8.1 (Berke
 #include <string.h>
 #include <unistd.h>
 
+#include <libcasper.h>
+#include <casper/cap_fileargs.h>
+
 #include "extern.h"
 
 static void rlines(FILE *, const char *fn, off_t, struct stat *);
@@ -310,6 +313,7 @@ follow(file_info_t *files, enum STYLE style, off_t off
 	int active, ev_change, i, n = -1;
 	struct stat sb2;
 	file_info_t *file;
+	FILE *ftmp;
 	struct timespec ts;
 
 	/* Position each of the files */
@@ -346,7 +350,9 @@ follow(file_info_t *files, enum STYLE style, off_t off
 		if (Fflag) {
 			for (i = 0, file = files; i < no_files; i++, file++) {
 				if (!file->fp) {
-					file->fp = fopen(file->file_name, "r");
+					file->fp =
+					    fileargs_fopen(fa, file->file_name,
+					    "r");
 					if (file->fp != NULL &&
 					    fstat(fileno(file->fp), &file->st)
 					    == -1) {
@@ -359,7 +365,9 @@ follow(file_info_t *files, enum STYLE style, off_t off
 				}
 				if (fileno(file->fp) == STDIN_FILENO)
 					continue;
-				if (stat(file->file_name, &sb2) == -1) {
+				ftmp = fileargs_fopen(fa, file->file_name, "r");
+				if (ftmp == NULL ||
+				    fstat(fileno(file->fp), &sb2) == -1) {
 					if (errno != ENOENT)
 						ierr(file->file_name);
 					show(file);
@@ -367,6 +375,9 @@ follow(file_info_t *files, enum STYLE style, off_t off
 						fclose(file->fp);
 						file->fp = NULL;
 					}
+					if (ftmp != NULL) {
+						fclose(ftmp);
+					}
 					ev_change++;
 					continue;
 				}
@@ -375,14 +386,13 @@ follow(file_info_t *files, enum STYLE style, off_t off
 				    sb2.st_dev != file->st.st_dev ||
 				    sb2.st_nlink == 0) {
 					show(file);
-					file->fp = freopen(file->file_name, "r",
-					    file->fp);
-					if (file->fp != NULL)
-						memcpy(&file->st, &sb2,
-						    sizeof(struct stat));
-					else if (errno != ENOENT)
-						ierr(file->file_name);
+					fclose(file->fp);
+					file->fp = ftmp;
+					memcpy(&file->st, &sb2,
+					    sizeof(struct stat));
 					ev_change++;
+				} else {
+					fclose(ftmp);
 				}
 			}
 		}

Modified: head/usr.bin/tail/misc.c
==============================================================================
--- head/usr.bin/tail/misc.c	Sun Jun  9 22:45:07 2019	(r348841)
+++ head/usr.bin/tail/misc.c	Sun Jun  9 22:55:21 2019	(r348842)
@@ -51,6 +51,9 @@ static const char sccsid[] = "@(#)misc.c	8.1 (Berkeley
 #include <string.h>
 #include <unistd.h>
 
+#include <libcasper.h>
+#include <casper/cap_fileargs.h>
+
 #include "extern.h"
 
 void

Modified: head/usr.bin/tail/read.c
==============================================================================
--- head/usr.bin/tail/read.c	Sun Jun  9 22:45:07 2019	(r348841)
+++ head/usr.bin/tail/read.c	Sun Jun  9 22:55:21 2019	(r348842)
@@ -51,6 +51,9 @@ static const char sccsid[] = "@(#)read.c	8.1 (Berkeley
 #include <string.h>
 #include <unistd.h>
 
+#include <libcasper.h>
+#include <casper/cap_fileargs.h>
+
 #include "extern.h"
 
 /*

Modified: head/usr.bin/tail/reverse.c
==============================================================================
--- head/usr.bin/tail/reverse.c	Sun Jun  9 22:45:07 2019	(r348841)
+++ head/usr.bin/tail/reverse.c	Sun Jun  9 22:55:21 2019	(r348842)
@@ -55,6 +55,9 @@ __FBSDID("$FreeBSD$");
 #include <string.h>
 #include <unistd.h>
 
+#include <libcasper.h>
+#include <casper/cap_fileargs.h>
+
 #include "extern.h"
 
 static void r_buf(FILE *, const char *);

Modified: head/usr.bin/tail/tail.c
==============================================================================
--- head/usr.bin/tail/tail.c	Sun Jun  9 22:45:07 2019	(r348841)
+++ head/usr.bin/tail/tail.c	Sun Jun  9 22:55:21 2019	(r348842)
@@ -65,6 +65,7 @@ static const char sccsid[] = "@(#)tail.c	8.1 (Berkeley
 #include "extern.h"
 
 int Fflag, fflag, qflag, rflag, rval, no_files;
+fileargs_t *fa;
 
 static file_info_t *files;
 
@@ -90,10 +91,9 @@ main(int argc, char *argv[])
 	int i, ch, first;
 	file_info_t *file;
 	char *p;
-	fileargs_t *fa;
 	cap_rights_t rights;
 
-	cap_rights_init(&rights, CAP_FSTAT, CAP_FCNTL, CAP_MMAP_RW);
+	cap_rights_init(&rights, CAP_FSTAT, CAP_FSTATFS, CAP_FCNTL, CAP_MMAP_RW);
 	if (caph_rights_limit(STDIN_FILENO, &rights) < 0 ||
 	    caph_limit_stderr() < 0 || caph_limit_stdout() < 0)
 		err(1, "can't limit stdio rights");