lsns: (refactor) use ul_new_path and procfs_process_init_path

Signed-off-by: Masatake YAMATO <yamato@redhat.com>

diff --git a/sys-utils/lsns.c b/sys-utils/lsns.c
index f444f5e1a51f65c0e45456cefc007d8ddac376f4..c328f046e168e5cbaefd3dce423acfeecfbe1145 100644 (file)
--- a/sys-utils/lsns.c
+++ b/sys-utils/lsns.c
@@ -297,14 +297,14 @@ static inline const struct colinfo *get_column_info(unsigned num)
        return &infos[ get_column_id(num) ];
 }
 
-static int get_ns_ino(int dir, const char *nsname, ino_t *ino, ino_t *pino, ino_t *oino)
+static int get_ns_ino(struct path_cxt *pc, const char *nsname, ino_t *ino, ino_t *pino, ino_t *oino)
 {
        struct stat st;
        char path[16];
 
        snprintf(path, sizeof(path), "ns/%s", nsname);
 
-       if (fstatat(dir, path, &st, 0) != 0)
+       if (ul_path_stat(pc, &st, 0, path) != 0)
                return -errno;
        *ino = st.st_ino;
 
@@ -313,7 +313,7 @@ static int get_ns_ino(int dir, const char *nsname, ino_t *ino, ino_t *pino, ino_
 
 #ifdef USE_NS_GET_API
        int fd, pfd, ofd;
-       fd = openat(dir, path, 0);
+       fd = ul_path_open(pc, 0, path);
        if (fd < 0)
                return -errno;
        if (strcmp(nsname, "pid") == 0 || strcmp(nsname, "user") == 0) {
@@ -351,17 +351,11 @@ static int get_ns_ino(int dir, const char *nsname, ino_t *ino, ino_t *pino, ino_
        return 0;
 }
 
-static int parse_proc_stat(FILE *fp, pid_t *pid, char *state, pid_t *ppid)
+static int parse_proc_stat(char *line, pid_t *pid, char *state, pid_t *ppid)
 {
-       char *line = NULL, *p;
-       size_t len = 0;
+       char *p;
        int rc;
 
-       if (getline(&line, &len, fp) < 0) {
-               rc = -errno;
-               goto error;
-       }
-
        p = strrchr(line, ')');
        if (p == NULL ||
            sscanf(line, "%d (", pid) != 1 ||
@@ -372,7 +366,6 @@ static int parse_proc_stat(FILE *fp, pid_t *pid, char *state, pid_t *ppid)
        rc = 0;
 
 error:
-       free(line);
        return rc;
 }
 
@@ -462,7 +455,7 @@ static int get_netnsid_via_netlink_recv_response(int *netnsid)
        return 0;
 }
 
-static int get_netnsid_via_netlink(int dir, const char *path)
+static int get_netnsid_via_netlink(struct path_cxt *pc, const char *path)
 {
        int netnsid;
        int target_fd;
@@ -470,7 +463,7 @@ static int get_netnsid_via_netlink(int dir, const char *path)
        if (netlink_fd < 0)
                return LSNS_NETNS_UNUSABLE;
 
-       target_fd = openat(dir, path, O_RDONLY);
+       target_fd = ul_path_open(pc, O_RDONLY, path);
        if (target_fd < 0)
                return LSNS_NETNS_UNUSABLE;
 
@@ -489,61 +482,41 @@ static int get_netnsid_via_netlink(int dir, const char *path)
        return netnsid;
 }
 
-static int get_netnsid(int dir, ino_t netino)
+static int get_netnsid(struct path_cxt *pc, ino_t netino)
 {
        int netnsid;
 
        if (!netnsid_cache_find(netino, &netnsid)) {
-               netnsid = get_netnsid_via_netlink(dir, "ns/net");
+               netnsid = get_netnsid_via_netlink(pc, "ns/net");
                netnsid_cache_add(netino, netnsid);
        }
 
        return netnsid;
 }
 #else
-static int get_netnsid(int dir __attribute__((__unused__)),
+static int get_netnsid(struct path_cxt *pc __attribute__((__unused__)),
                       ino_t netino __attribute__((__unused__)))
 {
        return LSNS_NETNS_UNUSABLE;
 }
 #endif /* HAVE_LINUX_NET_NAMESPACE_H */
 
-static int read_process(struct lsns *ls, pid_t pid)
+static int read_process(struct lsns *ls, struct path_cxt *pc)
 {
        struct lsns_process *p = NULL;
+       int rc = 0;
        char buf[BUFSIZ];
-       DIR *dir;
-       int rc = 0, fd;
-       FILE *f = NULL;
        size_t i;
-       struct stat st;
-
-       DBG(PROC, ul_debug("reading %d", (int) pid));
-
-       snprintf(buf, sizeof(buf), "/proc/%d", pid);
-       dir = opendir(buf);
-       if (!dir)
-               return -errno;
 
        p = xcalloc(1, sizeof(*p));
        p->netnsid = LSNS_NETNS_UNUSABLE;
 
-       if (fstat(dirfd(dir), &st) == 0) {
-               p->uid = st.st_uid;
-               add_uid(uid_cache, st.st_uid);
-       }
+       if (procfs_process_get_uid(pc, &p->uid) == 0)
+               add_uid(uid_cache, p->uid);
 
-       fd = openat(dirfd(dir), "stat", O_RDONLY);
-       if (fd < 0) {
-               rc = -errno;
+       if ((rc = procfs_process_get_stat(pc, buf, sizeof(buf))) < 0)
                goto done;
-       }
-       if (!(f = fdopen(fd, "r"))) {
-               rc = -errno;
-               goto done;
-       }
-       rc = parse_proc_stat(f, &p->pid, &p->state, &p->ppid);
-       if (rc < 0)
+       if ((rc = parse_proc_stat(buf, &p->pid, &p->state, &p->ppid)) < 0)
                goto done;
        rc = 0;
 
@@ -553,12 +526,12 @@ static int read_process(struct lsns *ls, pid_t pid)
                if (!ls->fltr_types[i])
                        continue;
 
-               rc = get_ns_ino(dirfd(dir), ns_names[i], &p->ns_ids[i],
+               rc = get_ns_ino(pc, ns_names[i], &p->ns_ids[i],
                                &p->ns_pids[i], &p->ns_oids[i]);
                if (rc && rc != -EACCES && rc != -ENOENT)
                        goto done;
                if (i == LSNS_ID_NET)
-                       p->netnsid = get_netnsid(dirfd(dir), p->ns_ids[i]);
+                       p->netnsid = get_netnsid(pc, p->ns_ids[i]);
                rc = 0;
        }
 
@@ -567,9 +540,6 @@ static int read_process(struct lsns *ls, pid_t pid)
        DBG(PROC, ul_debugobj(p, "new pid=%d", p->pid));
        list_add_tail(&p->processes, &ls->processes);
 done:
-       if (f)
-               fclose(f);
-       closedir(dir);
        if (rc)
                free(p);
        return rc;
@@ -580,6 +550,7 @@ static int read_processes(struct lsns *ls)
        DIR *dir;
        struct dirent *d;
        int rc = 0;
+       struct path_cxt *pc;
 
        DBG(PROC, ul_debug("opening /proc"));
 
@@ -587,20 +558,31 @@ static int read_processes(struct lsns *ls)
        if (!dir)
                return -errno;
 
+       pc = ul_new_path(NULL);
+       if (!pc)
+               err(EXIT_FAILURE, _("failed to alloc procfs handler"));
+
        while ((d = xreaddir(dir))) {
                pid_t pid = 0;
 
                if (procfs_dirent_get_pid(d, &pid) != 0)
                        continue;
 
-               /* TODO: use ul_new_procfs_path(pid, NULL) to read files from /proc/pid/
-                */
-               rc = read_process(ls, pid);
+               DBG(PROC, ul_debug("reading %d", (int) pid));
+               rc = procfs_process_init_path(pc, pid);
+               if (rc < 0) {
+                       DBG(PROC, ul_debug("failed in reading /proc/%d", (int) pid));
+                       continue;
+               }
+
+               rc = read_process(ls, pc);
                if (rc && rc != -EACCES && rc != -ENOENT)
                        break;
                rc = 0;
        }
 
+       ul_unref_path(pc);
+
        DBG(PROC, ul_debug("closing /proc"));
        closedir(dir);
        return rc;