Error check messages sent to the kernel.

And make sure that if we fail to export a filesystem in mountd,
then we don't try to get a filehandle on it, or a deadlock
might occur.

8 files changed, 37 insertions, 25 deletions

diff --git a/support/include/nfslib.h b/support/include/nfslib.h
index 3e25761..aba37c2 100644
--- a/support/include/nfslib.h
+++ b/support/include/nfslib.h
@@ -132,7 +132,7 @@ struct nfs_fh_len *	getfh_size(struct sockaddr *addr, const char *, int size);
 void qword_print(FILE *f, char *str);
 void qword_printhex(FILE *f, char *str, int slen);
 void qword_printint(FILE *f, int num);
-void qword_eol(FILE *f);
+int qword_eol(FILE *f);
 int readline(int fd, char **buf, int *lenp);
 int qword_get(char **bpp, char *dest, int bufsize);
 int qword_get_int(char **bpp, int *anint);
diff --git a/support/nfs/cacheio.c b/support/nfs/cacheio.c
index 3e868d8..36473cf 100644
--- a/support/nfs/cacheio.c
+++ b/support/nfs/cacheio.c
@@ -109,10 +109,10 @@ void qword_printint(FILE *f, int num)
 	fprintf(f, "%d ", num);
 }
 
-void qword_eol(FILE *f)
+int qword_eol(FILE *f)
 {
 	fprintf(f,"\n");
-	fflush(f);
+	return fflush(f);
 }
 
 
diff --git a/support/nfs/nfsexport.c b/support/nfs/nfsexport.c
index aa0e49b..f129fd2 100644
--- a/support/nfs/nfsexport.c
+++ b/support/nfs/nfsexport.c
@@ -38,6 +38,7 @@ exp_unexp(struct nfsctl_export *exp, int export)
 	char fsidstr[8];
 	__u16 dev;
 	__u32 inode;
+	int err;
 
 
 	f = fopen("/proc/net/rpc/nfsd.export/channel", "w");
@@ -53,7 +54,7 @@ exp_unexp(struct nfsctl_export *exp, int export)
 	} else
 		qword_printint(f, 1);
 
-	qword_eol(f);
+	err = qword_eol(f);
 	fclose(f);
 
 	if (stat(exp->ex_path, &stb) != 0)
@@ -71,7 +72,7 @@ exp_unexp(struct nfsctl_export *exp, int export)
 		} else
 			qword_printint(f, 1);
 
-		qword_eol(f);
+		err = qword_eol(f) || err;
 	}
 	qword_print(f,exp->ex_client);
 	qword_printint(f,0);
@@ -85,9 +86,9 @@ exp_unexp(struct nfsctl_export *exp, int export)
 		qword_print(f, exp->ex_path);
 	} else
 		qword_printint(f, 1);
-	qword_eol(f);
+	err = qword_eol(f) || err;
 	fclose(f);
-	return 0;
+	return err;
 }
 
 int
diff --git a/utils/gssd/cacheio.c b/utils/gssd/cacheio.c
index 75c7a5d..f2f2960 100644
--- a/utils/gssd/cacheio.c
+++ b/utils/gssd/cacheio.c
@@ -173,11 +173,13 @@ void qword_printint(FILE *f, int num)
 	printerr(2, "%d ", num);
 }
 
-void qword_eol(FILE *f)
+int qword_eol(FILE *f)
 {
+	int err;
 	fprintf(f,"\n");
-	fflush(f);
+	err = fflush(f);
 	printerr(2, "\n");
+	return err;
 }
 
 
diff --git a/utils/gssd/cacheio.h b/utils/gssd/cacheio.h
index cc97b36..dfff258 100644
--- a/utils/gssd/cacheio.h
+++ b/utils/gssd/cacheio.h
@@ -40,7 +40,7 @@ void qword_addeol(char **bpp, int *lp);
 void qword_print(FILE *f, char *str);
 void qword_printhex(FILE *f, char *str, int slen);
 void qword_printint(FILE *f, int num);
-void qword_eol(FILE *f);
+int qword_eol(FILE *f);
 int readline(int fd, char **buf, int *lenp);
 int qword_get(char **bpp, char *dest, int bufsize);
 int qword_get_int(char **bpp, int *anint);
diff --git a/utils/gssd/svcgssd_proc.c b/utils/gssd/svcgssd_proc.c
index 7981399..4037159 100644
--- a/utils/gssd/svcgssd_proc.c
+++ b/utils/gssd/svcgssd_proc.c
@@ -72,6 +72,7 @@ do_svc_downcall(gss_buffer_desc *out_handle, struct svc_cred *cred,
 	FILE *f;
 	int i;
 	char *fname = NULL;
+	int err;
 
 	printerr(1, "doing downcall\n");
 	if ((fname = mech2file(mech)) == NULL)
@@ -93,9 +94,9 @@ do_svc_downcall(gss_buffer_desc *out_handle, struct svc_cred *cred,
 		qword_printint(f, cred->cr_groups[i]);
 	qword_print(f, fname);
 	qword_printhex(f, context_token->value, context_token->length);
-	qword_eol(f);
+	err = qword_eol(f);
 	fclose(f);
-	return 0;
+	return err;
 out_err:
 	printerr(0, "WARNING: downcall failed\n");
 	return -1;
diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c
index 726b98f..dcb5dac 100644
--- a/utils/mountd/cache.c
+++ b/utils/mountd/cache.c
@@ -35,7 +35,7 @@
  * Record is terminated with newline.
  *
  */
-void cache_export_ent(char *domain, struct exportent *exp);
+int cache_export_ent(char *domain, struct exportent *exp);
 
 
 char *lbuf  = NULL;
@@ -352,12 +352,12 @@ int cache_process_req(fd_set *readfds)
  * % echo $domain $path $[now+30*60] $options $anonuid $anongid $fsid > /proc/net/rpc/nfsd.export/channel
  */
 
-void cache_export_ent(char *domain, struct exportent *exp)
+int cache_export_ent(char *domain, struct exportent *exp)
 {
-
+	int err;
 	FILE *f = fopen("/proc/net/rpc/nfsd.export/channel", "w");
 	if (!f)
-		return;
+		return -1;
 
 	qword_print(f, domain);
 	qword_print(f, exp->e_path);
@@ -366,28 +366,32 @@ void cache_export_ent(char *domain, struct exportent *exp)
 	qword_printint(f, exp->e_anonuid);
 	qword_printint(f, exp->e_anongid);
 	qword_printint(f, exp->e_fsid);
-	qword_eol(f);
+	err = qword_eol(f);
 
 	fclose(f);
+	return err;
 }
 
-void cache_export(nfs_export *exp)
+int cache_export(nfs_export *exp)
 {
+	int err;
 	FILE *f;
 
 	f = fopen("/proc/net/rpc/auth.unix.ip/channel", "w");
 	if (!f)
-		return;
+		return -1;
 
 	qword_print(f, "nfsd");
 	qword_print(f, inet_ntoa(exp->m_client->m_addrlist[0]));
 	qword_printint(f, time(0)+30*60);
 	qword_print(f, exp->m_client->m_hostname);
-	qword_eol(f);
+	err = qword_eol(f);
 	
 	fclose(f);
 
-	cache_export_ent(exp->m_client->m_hostname, &exp->m_export);
+	err = cache_export_ent(exp->m_client->m_hostname, &exp->m_export)
+		|| err;
+	return err;
 }
 
 /* Get a filehandle.
@@ -413,9 +417,10 @@ cache_get_filehandle(nfs_export *exp, int len, char *p)
 	qword_print(f, exp->m_client->m_hostname);
 	qword_print(f, p);
 	qword_printint(f, len);	
-	qword_eol(f);
+	failed = qword_eol(f);
 	
-	failed = (fgets(buf, sizeof(buf), f) == NULL);
+	if (!failed)
+		failed = (fgets(buf, sizeof(buf), f) == NULL);
 	fclose(f);
 	if (failed)
 		return NULL;
diff --git a/utils/mountd/mountd.c b/utils/mountd/mountd.c
index 08f294d..72332ce 100644
--- a/utils/mountd/mountd.c
+++ b/utils/mountd/mountd.c
@@ -29,7 +29,7 @@
 
 extern void	cache_open(void);
 extern struct nfs_fh_len *cache_get_filehandle(nfs_export *exp, int len, char *p);
-extern void cache_export(nfs_export *exp);
+extern int cache_export(nfs_export *exp);
 
 extern void my_svc_run(void);
 
@@ -416,7 +416,10 @@ get_rootfh(struct svc_req *rqstp, dirpath *path, mountstat3 *error, int v3)
 		 */
 		struct nfs_fh_len  *fh;
 
-		cache_export(exp);
+		if (cache_export(exp)) {
+			*error = NFSERR_ACCES;
+			return NULL;
+		}
 		fh = cache_get_filehandle(exp, v3?64:32, p);
 		if (fh == NULL) 
 			*error = NFSERR_ACCES;