ipcs: clean up do_sem(), and add ipc_sem_get_info()

Signed-off-by: Sami Kerola <kerolasa@iki.fi>

3 files changed, 164 insertions, 40 deletions

diff --git a/sys-utils/ipcs.c b/sys-utils/ipcs.c
index 4945d8dcc..1180299eb 100644
--- a/sys-utils/ipcs.c
+++ b/sys-utils/ipcs.c
@@ -33,8 +33,8 @@
 
 static void do_shm (char format);
 static void print_shm (int id);
+static void do_sem (char format);
 
-void do_sem (char format);
 void do_msg (char format);
 void print_msg (int id);
 void print_sem (int id);
@@ -332,25 +332,16 @@ static void do_shm (char format)
 	return;
 }
 
-void do_sem (char format)
+static void do_sem (char format)
 {
-	int maxid, semid, id;
-	struct semid_ds semary;
-	struct seminfo seminfo;
-	struct ipc_perm *ipcp = &semary.sem_perm;
 	struct passwd *pw;
-	union semun arg;
-	struct ipc_limits lim;
-
-	arg.array = (ushort *)  (void *) &seminfo;
-	maxid = semctl (0, 0, SEM_INFO, arg);
-	if (maxid < 0) {
-		printf (_("kernel not configured for semaphores\n"));
-		return;
-	}
+	struct sem_data *semds, *semdsp;
 
 	switch (format) {
 	case LIMITS:
+	{
+		struct ipc_limits lim;
+
 		printf (_("------ Semaphore Limits --------\n"));
 		if (ipc_sem_get_limits(&lim))
 			return;
@@ -360,12 +351,21 @@ void do_sem (char format)
 		printf (_("max ops per semop call = %d\n"), lim.semopm);
 		printf (_("semaphore max value = %d\n"), lim.semvmx);
 		return;
-
+	}
 	case STATUS:
+	{
+		struct seminfo seminfo;
+		union semun arg;
+		arg.array = (ushort *)  (void *) &seminfo;
+		if (semctl (0, 0, SEM_INFO, arg) < 0) {
+			printf (_("kernel not configured for semaphores\n"));
+			return;
+		}
 		printf (_("------ Semaphore Status --------\n"));
 		printf (_("used arrays = %d\n"), seminfo.semusz);
 		printf (_("allocated semaphores = %d\n"), seminfo.semaem);
 		return;
+	}
 
 	case CREATOR:
 		printf (_("------ Semaphore Arrays Creators/Owners --------\n"));
@@ -389,48 +389,48 @@ void do_sem (char format)
 		break;
 	}
 
-	for (id = 0; id <= maxid; id++) {
-		arg.buf = (struct semid_ds *) &semary;
-		semid = semctl (id, 0, SEM_STAT, arg);
-		if (semid < 0)
-			continue;
+	/*
+	 * Print data
+	 */
+	if (ipc_sem_get_info(-1, &semds) < 1)
+		return;
+	semdsp = semds;
+
+	for (semdsp = semds; semdsp->next != NULL; semdsp = semdsp->next) {
 		if (format == CREATOR)  {
-			print_perms (semid, ipcp);
+			ipc_print_perms(stdout, &semdsp->sem_perm);
 			continue;
 		}
-		pw = getpwuid(ipcp->uid);
+		pw = getpwuid(semdsp->sem_perm.uid);
 		switch (format) {
 		case TIME:
 			if (pw)
-				printf ("%-8d %-10.10s", semid, pw->pw_name);
+				printf ("%-8d %-10.10s", semdsp->sem_perm.id, pw->pw_name);
 			else
-				printf ("%-8d %-10u", semid, ipcp->uid);
-			printf ("  %-26.24s", semary.sem_otime
-				? ctime(&semary.sem_otime) : _("Not set"));
-			printf (" %-26.24s\n", semary.sem_ctime
-				? ctime(&semary.sem_ctime) : _("Not set"));
+				printf ("%-8d %-10u", semdsp->sem_perm.id, semdsp->sem_perm.uid);
+			printf ("  %-26.24s", semdsp->sem_otime
+				? ctime(&semdsp->sem_otime) : _("Not set"));
+			printf (" %-26.24s\n", semdsp->sem_ctime
+				? ctime(&semdsp->sem_ctime) : _("Not set"));
 			break;
 		case PID:
 			break;
 
 		default:
-			printf("0x%08x ", ipcp->KEY);
+			printf("0x%08x ", semdsp->sem_perm.key);
 			if (pw)
-				printf ("%-10d %-10.10s", semid, pw->pw_name);
+				printf ("%-10d %-10.10s", semdsp->sem_perm.id, pw->pw_name);
 			else
-				printf ("%-10d %-10u", semid, ipcp->uid);
+				printf ("%-10d %-10u", semdsp->sem_perm.id, semdsp->sem_perm.uid);
 			printf (" %-10o %-10ld\n",
-				ipcp->mode & 0777,
-				/*
-				 * glibc-2.1.3 and earlier has unsigned
-				 * short. glibc-2.1.91 has variation between
-				 * unsigned short and unsigned long. Austin
-				 * prescribes unsigned short.
-				 */
-				(long) semary.sem_nsems);
+				semdsp->sem_perm.mode & 0777,
+				semdsp->sem_nsems);
 			break;
 		}
 	}
+
+	ipc_sem_free_info(semds);
+	return;
 }
 
 void do_msg (char format)
diff --git a/sys-utils/ipcutils.c b/sys-utils/ipcutils.c
index 3b52a7e6b..61671c128 100644
--- a/sys-utils/ipcutils.c
+++ b/sys-utils/ipcutils.c
@@ -211,6 +211,115 @@ void ipc_shm_free_info(struct shm_data *shmds)
 	}
 }
 
+int ipc_sem_get_info(int id, struct sem_data **semds)
+{
+	FILE *f;
+	int i, maxid;
+	struct sem_data *p;
+	struct seminfo dummy;
+	union semun arg;
+
+	p = *semds = xcalloc(1, sizeof(struct sem_data));
+	p->next = NULL;
+
+	f = path_fopen("r", 0, _PATH_PROC_SYSV_SEM);
+	if (!f)
+		goto sem_fallback;
+
+	while (fgetc(f) != '\n') ;	/* skip header */
+
+	while (feof(f) == 0) {
+		if (fscanf(f,
+			   "%d %d  %o %" SCNu64 " %u %u %u %u %" SCNu64 " %" SCNu64 "\n",
+			   &p->sem_perm.key,
+			   &p->sem_perm.id,
+			   &p->sem_perm.mode,
+			   &p->sem_nsems,
+			   &p->sem_perm.uid,
+			   &p->sem_perm.gid,
+			   &p->sem_perm.cuid,
+			   &p->sem_perm.cgid,
+			   &p->sem_otime,
+			   &p->sem_ctime) != 10)
+			continue;
+
+		if (id > -1) {
+			/* ID specified */
+			if (id == p->sem_perm.id) {
+				i = 1;
+				break;
+			} else
+				continue;
+		}
+
+		p->next = xcalloc(1, sizeof(struct sem_data));
+		p = p->next;
+		p->next = NULL;
+		i++;
+	}
+
+	if (i == 0)
+		free(*semds);
+	fclose(f);
+	return i;
+
+	/* Fallback; /proc or /sys file(s) missing. */
+ sem_fallback:
+	i = id < 0 ? 0 : id;
+
+	arg.array = (ushort *) (void *)&dummy;
+	maxid = semctl(0, 0, SEM_INFO, arg);
+	if (maxid < 0)
+		return 0;
+
+	while (i <= maxid) {
+		int semid;
+		struct semid_ds semseg;
+		struct ipc_perm *ipcp = &semseg.sem_perm;
+		arg.buf = (struct semid_ds *)&semseg;
+
+		semid = semctl(i, 0, SEM_STAT, arg);
+		if (semid < 0) {
+			if (-1 < id) {
+				free(*semds);
+				return 0;
+			}
+			i++;
+			continue;
+		}
+
+		p->sem_perm.key = ipcp->KEY;
+		p->sem_perm.id = semid;
+		p->sem_perm.mode = ipcp->mode;
+		p->sem_nsems = semseg.sem_nsems;
+		p->sem_perm.uid = ipcp->uid;
+		p->sem_perm.gid = ipcp->gid;
+		p->sem_perm.cuid = ipcp->cuid;
+		p->sem_perm.cgid = ipcp->cuid;
+		p->sem_otime = semseg.sem_otime;
+		p->sem_ctime = semseg.sem_ctime;
+
+		if (id < 0) {
+			p->next = xcalloc(1, sizeof(struct sem_data));
+			p = p->next;
+			p->next = NULL;
+			i++;
+		} else
+			return 1;
+	}
+
+	return i;
+}
+
+void ipc_sem_free_info(struct sem_data *semds)
+{
+	while (semds) {
+		struct sem_data *next = semds->next;
+		free(semds);
+		semds = next;
+	}
+}
+
 void ipc_print_perms(FILE *f, struct ipc_stat *is)
 {
 	struct passwd *pw;
diff --git a/sys-utils/ipcutils.h b/sys-utils/ipcutils.h
index 45a75d84f..3ab5da0ca 100644
--- a/sys-utils/ipcutils.h
+++ b/sys-utils/ipcutils.h
@@ -132,4 +132,19 @@ struct shm_data {
 extern int ipc_shm_get_info(int id, struct shm_data **shmds);
 extern void ipc_shm_free_info(struct shm_data *shmds);
 
+/* See 'struct sem_array' in kernel sources
+ */
+struct sem_data {
+	struct ipc_stat sem_perm;
+
+	time_t		sem_ctime;
+	time_t		sem_otime;
+	uint64_t	sem_nsems;
+
+	struct sem_data *next;
+};
+
+extern int ipc_sem_get_info(int id, struct sem_data **semds);
+extern void ipc_sem_free_info(struct sem_data *semds);
+
 #endif /* UTIL_LINUX_IPCUTILS_H */