Use stpeprintf() where appropriate

This function allows reducing error checking (since errors are
propagated across chained calls), and also simplifies the calculation of
the start and end of the buffer where the string should be written.

Moreover, the new code is more optimized, since many calls to strlen(3)
have been removed.

Signed-off-by: Alejandro Colomar <alx@kernel.org>

diff --git a/libmisc/idmapping.c b/libmisc/idmapping.c
index 57e9ab229f9ad12106945bb6e65a074340a37455..1c6e719f0f71b736618bc7ad71c82463f4cbc850 100644 (file)
--- a/libmisc/idmapping.c
+++ b/libmisc/idmapping.c
@@ -12,6 +12,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include "prototypes.h"
+#include "stpeprintf.h"
 #include "idmapping.h"
 #if HAVE_SYS_CAPABILITY_H
 #include <sys/prctl.h>
@@ -141,7 +142,7 @@ void write_mapping(int proc_dir_fd, int ranges, const struct map_range *mappings
        int idx;
        const struct map_range *mapping;
        size_t bufsize;
-       char *buf, *pos;
+       char *buf, *pos, *end;
        int fd;
 
 #if HAVE_SYS_CAPABILITY_H
@@ -189,21 +190,20 @@ void write_mapping(int proc_dir_fd, int ranges, const struct map_range *mappings
 
        bufsize = ranges * ((ULONG_DIGITS + 1) * 3);
        pos = buf = xmalloc(bufsize);
+       end = buf + bufsize;
 
        /* Build the mapping command */
        mapping = mappings;
        for (idx = 0; idx < ranges; idx++, mapping++) {
                /* Append this range to the string that will be written */
-               int written = snprintf(pos, bufsize - (pos - buf),
-                       "%lu %lu %lu\n",
-                       mapping->upper,
-                       mapping->lower,
-                       mapping->count);
-               if ((written <= 0) || ((size_t)written >= (bufsize - (pos - buf)))) {
-                       fprintf(log_get_logfd(), _("%s: snprintf failed!\n"), log_get_progname());
-                       exit(EXIT_FAILURE);
-               }
-               pos += written;
+               pos = stpeprintf(pos, end, "%lu %lu %lu\n",
+                                mapping->upper,
+                                mapping->lower,
+                                mapping->count);
+       }
+       if (pos == end || pos == NULL) {
+               fprintf(log_get_logfd(), _("%s: stpeprintf failed!\n"), log_get_progname());
+               exit(EXIT_FAILURE);
        }
 
        /* Write the mapping to the mapping file */

diff --git a/src/groupmod.c b/src/groupmod.c
index 4921aca3f3f7f0e985056c67a93bfb1821db1570..3799235cda632e36d84f8ba9ef10cc22c1604b27 100644 (file)
--- a/src/groupmod.c
+++ b/src/groupmod.c
@@ -35,6 +35,7 @@
 #include "sgroupio.h"
 #endif
 #include "shadowlog.h"
+#include "stpeprintf.h"
 /*
  * exit status values
  */
@@ -543,46 +544,49 @@ static void close_files (void)
  */
 static void prepare_failure_reports (void)
 {
+       char *gr, *gr_end;
+#ifdef SHADOWGRP
+       char *sgr, *sgr_end;
+#endif
+       char *pw, *pw_end;
+
        info_group.name   = group_name;
 #ifdef SHADOWGRP
        info_gshadow.name = group_name;
 #endif
        info_passwd.name  = group_name;
 
-       info_group.audit_msg   = xmalloc (512);
+       gr                     = xmalloc (512);
+       info_group.audit_msg   = gr;
+       gr_end                 = gr + 512;
 #ifdef SHADOWGRP
-       info_gshadow.audit_msg = xmalloc (512);
+       sgr                    = xmalloc (512);
+       info_gshadow.audit_msg = sgr;
+       sgr_end                = sgr + 512;
 #endif
-       info_passwd.audit_msg  = xmalloc (512);
+       pw                     = xmalloc (512);
+       info_passwd.audit_msg  = pw;
+       pw_end                 = pw + 512;
 
-       (void) snprintf (info_group.audit_msg, 512,
-                        "changing %s; ", gr_dbname ());
+       gr = stpeprintf(gr, gr_end, "changing %s; ", gr_dbname ());
 #ifdef SHADOWGRP
-       (void) snprintf (info_gshadow.audit_msg, 512,
-                        "changing %s; ", sgr_dbname ());
+       sgr = stpeprintf(sgr, sgr_end, "changing %s; ", sgr_dbname ());
 #endif
-       (void) snprintf (info_passwd.audit_msg, 512,
-                        "changing %s; ", pw_dbname ());
+       pw = stpeprintf(pw, pw_end, "changing %s; ", pw_dbname ());
 
-       info_group.action   =   info_group.audit_msg
-                             + strlen (info_group.audit_msg);
+       info_group.action   = gr;
 #ifdef SHADOWGRP
-       info_gshadow.action =   info_gshadow.audit_msg
-                             + strlen (info_gshadow.audit_msg);
+       info_gshadow.action = sgr;
 #endif
-       info_passwd.action  =   info_passwd.audit_msg
-                             + strlen (info_passwd.audit_msg);
+       info_passwd.action  = pw;
 
-       (void) snprintf (info_group.action,
-                        512 - strlen (info_group.audit_msg),
+       gr  = stpeprintf(gr, gr_end,
                         "group %s/%ju", group_name, (uintmax_t) group_id);
 #ifdef SHADOWGRP
-       (void) snprintf (info_gshadow.action,
-                        512 - strlen (info_gshadow.audit_msg),
+       sgr = stpeprintf(sgr, sgr_end,
                         "group %s", group_name);
 #endif
-       (void) snprintf (info_passwd.action,
-                        512 - strlen (info_passwd.audit_msg),
+       pw  = stpeprintf(pw, pw_end,
                         "group %s/%ju", group_name, (uintmax_t) group_id);
 
        if (nflg) {
@@ -615,15 +619,13 @@ static void prepare_failure_reports (void)
        if (gflg) {
                strncat (info_group.action, ", new gid: ",
                         511 - strlen (info_group.audit_msg));
-               (void) snprintf (info_group.action+strlen (info_group.action),
-                                512 - strlen (info_group.audit_msg),
-                                "%ju", (uintmax_t) group_newid);
+               stpeprintf(info_group.action+strlen (info_group.action),
+                                gr_end, "%ju", (uintmax_t) group_newid);
 
                strncat (info_passwd.action, ", new gid: ",
                         511 - strlen (info_passwd.audit_msg));
-               (void) snprintf (info_passwd.action+strlen (info_passwd.action),
-                                512 - strlen (info_passwd.audit_msg),
-                                "%ju", (uintmax_t) group_newid);
+               stpeprintf(info_passwd.action+strlen (info_passwd.action),
+                                pw_end, "%ju", (uintmax_t) group_newid);
        }
        info_group.audit_msg[511]   = '\0';
 #ifdef SHADOWGRP