Re: make rdaemon less error-prone

[Jeremie Courreges-Anglas]

j...@wxcvbn.org (Jeremie Courreges-Anglas) writes:

> Simple idiom: always initialize the pre-opened fd to -1, and within
> rdaemon() test whether the passed fd is valid.
>
> ok?

Updated diff after Theo suggested avoiding the fcntl call if possible.


Index: usr.sbin/rtadvd/rtadvd.c
===================================================================
RCS file: /cvs/src/usr.sbin/rtadvd/rtadvd.c,v
retrieving revision 1.81
diff -u -p -r1.81 rtadvd.c
--- usr.sbin/rtadvd/rtadvd.c    21 Sep 2016 18:54:24 -0000      1.81
+++ usr.sbin/rtadvd/rtadvd.c    24 Sep 2016 17:56:55 -0000
@@ -1320,6 +1320,12 @@ ra_timer_update(struct rainfo *rai)
 int
 rdaemon(int devnull)
 {
+       if (devnull == -1) {
+               errno = EBADF;
+               return (-1);
+       }
+       if (fcntl(devnull, F_GETFL) == -1)
+               return (-1);
 
        switch (fork()) {
        case -1:
Index: usr.sbin/dhcrelay/dhcrelay.c
===================================================================
RCS file: /cvs/src/usr.sbin/dhcrelay/dhcrelay.c,v
retrieving revision 1.42
diff -u -p -r1.42 dhcrelay.c
--- usr.sbin/dhcrelay/dhcrelay.c        15 Sep 2016 16:16:03 -0000      1.42
+++ usr.sbin/dhcrelay/dhcrelay.c        24 Sep 2016 17:22:20 -0000
@@ -368,6 +368,12 @@ usage(void)
 int
 rdaemon(int devnull)
 {
+       if (devnull == -1) {
+               errno = EBADF;
+               return (-1);
+       }
+       if (fcntl(devnull, F_GETFL) == -1)
+               return (-1);
 
        switch (fork()) {
        case -1:
Index: usr.sbin/ftp-proxy/ftp-proxy.c
===================================================================
RCS file: /cvs/src/usr.sbin/ftp-proxy/ftp-proxy.c,v
retrieving revision 1.35
diff -u -p -r1.35 ftp-proxy.c
--- usr.sbin/ftp-proxy/ftp-proxy.c      15 Sep 2016 16:16:03 -0000      1.35
+++ usr.sbin/ftp-proxy/ftp-proxy.c      24 Sep 2016 17:55:37 -0000
@@ -633,6 +633,7 @@ main(int argc, char *argv[])
        verbose         = 0;
 
        /* Other initialization. */
+       devnull         = -1;
        id_count        = 1;
        session_count   = 0;
 
@@ -1142,6 +1143,12 @@ usage(void)
 int
 rdaemon(int devnull)
 {
+       if (devnull == -1) {
+               errno = EBADF;
+               return (-1);
+       }
+       if (fcntl(devnull, F_GETFL) == -1)
+               return (-1);
 
        switch (fork()) {
        case -1:
Index: usr.sbin/tftpd/tftpd.c
===================================================================
RCS file: /cvs/src/usr.sbin/tftpd/tftpd.c,v
retrieving revision 1.37
diff -u -p -r1.37 tftpd.c
--- usr.sbin/tftpd/tftpd.c      4 Sep 2016 14:41:49 -0000       1.37
+++ usr.sbin/tftpd/tftpd.c      24 Sep 2016 17:55:58 -0000
@@ -1584,6 +1584,12 @@ getip(void *s)
 int
 rdaemon(int devnull)
 {
+       if (devnull == -1) {
+               errno = EBADF;
+               return (-1);
+       }
+       if (fcntl(devnull, F_GETFL) == -1)
+               return (-1);
 
        switch (fork()) {
        case -1:


-- 
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