lib: Get RIB attributes from component

This revises the RIB so it gets the complete file attribute list from
the component instead of setting some attributes in the library. This
will allow setting read/write access later on in the component
itself. The time of last change of lsdb entries in the file system is
now set to the time of the last received Link State Update for that
entry.

Signed-off-by: Dimitri Staessens <dimitri.staessens@ugent.be>
Signed-off-by: Sander Vrijders <sander.vrijders@ugent.be>

3 files changed, 132 insertions, 52 deletions

diff --git a/include/ouroboros/rib.h b/include/ouroboros/rib.h
index fda36ead..5a3d66dc 100644
--- a/include/ouroboros/rib.h
+++ b/include/ouroboros/rib.h
@@ -25,6 +25,9 @@
 
 #define RIB_PATH_LEN 128
 
+#include <sys/stat.h>
+#include <sys/types.h>
+
 struct rib;
 
 struct rib_ops {
@@ -32,6 +35,8 @@ struct rib_ops {
                      char *       buf,
                      size_t       len);
         int (* readdir)(char *** entries);
+        int (* getattr)(const char *  path,
+                        struct stat * st);
 };
 
 int  rib_init(const char * prefix);
diff --git a/src/ipcpd/normal/pol/link_state.c b/src/ipcpd/normal/pol/link_state.c
index 520e2952..179a3448 100644
--- a/src/ipcpd/normal/pol/link_state.c
+++ b/src/ipcpd/normal/pol/link_state.c
@@ -52,6 +52,7 @@
 #define RECALC_TIME    4
 #define LS_UPDATE_TIME 15
 #define LS_TIMEO       60
+#define LS_ENTRY_SIZE  78
 #define LSDB           "lsdb"
 
 #ifndef CLOCK_REALTIME_COARSE
@@ -131,51 +132,96 @@ static int str_adj(struct adjacency * adj,
                    size_t             len)
 {
         char        tmbuf[64];
+        char        srcbuf[64];
+        char        dstbuf[64];
         struct tm * tm;
 
-        if (len < 256)
+        if (len < LS_ENTRY_SIZE)
                 return -1;
 
         tm = localtime(&adj->stamp);
-        strftime(tmbuf, sizeof(tmbuf), "%Y-%m-%d %H:%M:%S", tm);
+        strftime(tmbuf, sizeof(tmbuf), "%F %T", tm); /* 19 chars */
 
-        sprintf(buf,
-                "src: %" PRIu64 "\n"
-                "dst: %" PRIu64 "\n"
-                "upd: %s\n",
-                adj->src,
-                adj->dst,
-                tmbuf);
+        sprintf(srcbuf, "%" PRIu64, adj->src);
+        sprintf(dstbuf, "%" PRIu64, adj->dst);
 
-        return strlen(buf);
+        sprintf(buf, "src: %20s\ndst: %20s\nupd: %20s\n",
+                srcbuf, dstbuf, tmbuf);
+
+        return LS_ENTRY_SIZE;
 }
 
-static int lsdb_read(const char * path,
-                     char *       buf,
-                     size_t       len)
+static struct adjacency * get_adj(const char * path)
 {
         struct list_head * p;
         char               entry[RIB_PATH_LEN + 1];
 
-        pthread_rwlock_rdlock(&ls.db_lock);
-
-        if (ls.db_len + ls.nbs_len == 0) {
-                pthread_rwlock_unlock(&ls.db_lock);
-                return -EPERM;
-        }
+        assert(path);
 
         list_for_each(p, &ls.db) {
                 struct adjacency * a = list_entry(p, struct adjacency, next);
                 sprintf(entry, "%" PRIu64 ".%" PRIu64, a->src, a->dst);
-                if (strcmp(entry, path) == 0) {
-                        len = str_adj(a, buf, len);
-                        pthread_rwlock_unlock(&ls.db_lock);
-                        return len;
-                }
+                if (strcmp(entry, path) == 0)
+                        return a;
+        }
+
+        return NULL;
+}
+
+static int lsdb_getattr(const char *  path,
+                        struct stat * st)
+{
+        struct adjacency * adj;
+        struct timespec    now;
+
+        clock_gettime(CLOCK_REALTIME_COARSE, &now);
+
+        pthread_rwlock_rdlock(&ls.db_lock);
+
+        adj = get_adj(path);
+        if (adj != NULL) {
+                st->st_mtime = adj->stamp;
+                st->st_size  = LS_ENTRY_SIZE;
+        } else {
+                st->st_mtime = now.tv_sec;
+                st->st_size  = 0;
         }
 
+        st->st_mode  = S_IFREG | 0755;
+        st->st_nlink = 1;
+        st->st_uid   = getuid();
+        st->st_gid   = getgid();
+
+        pthread_rwlock_unlock(&ls.db_lock);
+
+        return 0;
+}
+
+static int lsdb_read(const char * path,
+                     char *       buf,
+                     size_t       len)
+{
+        struct adjacency * a;
+        int                size;
+
+        pthread_rwlock_rdlock(&ls.db_lock);
+
+        if (ls.db_len + ls.nbs_len == 0)
+                goto fail;
+
+        a = get_adj(path);
+        if (a == NULL)
+                goto fail;
+
+        size = str_adj(a, buf, len);
+        if (size < 0)
+                goto fail;
+
         pthread_rwlock_unlock(&ls.db_lock);
+        return size;
 
+ fail:
+        pthread_rwlock_unlock(&ls.db_lock);
         return -1;
 }
 
@@ -204,8 +250,8 @@ static int lsdb_readdir(char *** buf)
                 sprintf(entry, "%s%" PRIu64, str, nb->addr);
                 (*buf)[idx] = malloc(strlen(entry) + 1);
                 if ((*buf)[idx] == NULL) {
-                        while (--idx >= 0)
-                                free(*buf[idx]);
+                        while (idx-- > 0)
+                                free((*buf)[idx]);
                         free(buf);
                         pthread_rwlock_unlock(&ls.db_lock);
                         return -ENOMEM;
@@ -241,7 +287,8 @@ static int lsdb_readdir(char *** buf)
 
 static struct rib_ops r_ops = {
         .read    = lsdb_read,
-        .readdir = lsdb_readdir
+        .readdir = lsdb_readdir,
+        .getattr = lsdb_getattr
 };
 
 static int lsdb_add_nb(uint64_t     addr,
@@ -801,13 +848,17 @@ int link_state_init(enum pol_routing pr)
         if (pthread_create(&ls.listener, NULL, ls_conn_handle, NULL))
                 goto fail_pthread_create_listener;
 
+        if (rib_reg(LSDB, &r_ops))
+                goto fail_rib_reg;
+
         ls.db_len  = 0;
         ls.nbs_len = 0;
 
-        rib_reg(LSDB, &r_ops);
-
         return 0;
 
+ fail_rib_reg:
+        pthread_cancel(ls.listener);
+        pthread_join(ls.listener, NULL);
  fail_pthread_create_listener:
         pthread_cancel(ls.lsreader);
         pthread_join(ls.lsreader, NULL);
diff --git a/src/lib/rib.c b/src/lib/rib.c
index 5bb8c1c3..947226a9 100644
--- a/src/lib/rib.c
+++ b/src/lib/rib.c
@@ -29,6 +29,7 @@
 #include <ouroboros/rib.h>
 #include <ouroboros/utils.h>
 
+#include <assert.h>
 #include <pthread.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -155,9 +156,11 @@ static int rib_readdir(const char *            path,
                         ssize_t           i;
                         struct reg_comp * c;
                         c = list_entry(p, struct reg_comp, next);
-                        if (strcmp(path + 1, c->path) == 0)
-                                if (c->ops->readdir == NULL)
-                                        break;
+
+                        if (strcmp(path + 1, c->path) != 0)
+                                continue;
+
+                        assert(c->ops->readdir != NULL);
 
                         len = c->ops->readdir(&dir_entries);
                         if (len < 0)
@@ -173,49 +176,70 @@ static int rib_readdir(const char *            path,
         return 0;
 }
 
+static size_t __getattr(const char *  path,
+                        struct stat * st)
+{
+        struct list_head * p;
+        char               comp[RIB_PATH_LEN + 1];
+        char *             c;
+
+        strcpy(comp, path + 1);
+
+        c = strstr(comp, "/");
+
+        if (c != NULL)
+                *c = '\0';
+
+        pthread_rwlock_rdlock(&rib.lock);
+
+        list_for_each(p, &rib.reg_comps) {
+                struct reg_comp * r = list_entry(p, struct reg_comp, next);
+                if (strcmp(comp, r->path) == 0) {
+                        size_t ret = r->ops->getattr(c + 1, st);
+                        pthread_rwlock_unlock(&rib.lock);
+                        return ret;
+                }
+        }
+
+        pthread_rwlock_unlock(&rib.lock);
+
+        return -1;
+}
+
 static int rib_getattr(const char *  path,
                        struct stat * st)
 {
         struct list_head * p;
         struct timespec    now;
 
-        clock_gettime(CLOCK_REALTIME_COARSE, &now);
-
         memset(st, 0, sizeof(*st));
 
-        if (strcmp(path, RT) == 0) {
-                st->st_mode  = S_IFDIR | 0755;
-                st->st_nlink = 2;
-                st->st_uid   = getuid();
-                st->st_gid   = getgid();
-                st->st_mtime = now.tv_sec;
-                return 0;
-        }
+        if (strcmp(path, RT) == 0)
+                goto finish_dir;
 
         pthread_rwlock_rdlock(&rib.lock);
 
         list_for_each(p, &rib.reg_comps) {
                 struct reg_comp * rc = list_entry(p, struct reg_comp, next);
                 if (strcmp(path + 1, rc->path) == 0) {
-                        st->st_mode  = S_IFDIR | 0755;
-                        st->st_nlink = 2;
-                        break;
+                        pthread_rwlock_unlock(&rib.lock);
+                        goto finish_dir;
                 }
         }
 
         pthread_rwlock_unlock(&rib.lock);
 
-        if (st->st_mode == 0) {
-                char buf[4096];
-                st->st_nlink = 2;
-                st->st_mode = S_IFREG | 0755;
-                st->st_size = rib_read(path, buf, 4096, 0, NULL);
-        }
+        assert(st->st_mode == 0);
+
+        return __getattr(path, st);
 
+ finish_dir:
+        clock_gettime(CLOCK_REALTIME_COARSE, &now);
+        st->st_mode  = S_IFDIR | 0755;
+        st->st_nlink = 2;
         st->st_uid   = getuid();
         st->st_gid   = getgid();
         st->st_mtime = now.tv_sec;
-
         return 0;
 }