logd: add support for sending log messages as replies

Useful for JSON-RPC access via uhttpd

Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/log/logd.c b/log/logd.c
index 27d3cac8abdda9227e51f0d113cbef09bad5d3c7..3f8045912f1a6d88b844005ceaa58a81ba4d2656 100644 (file)
--- a/log/logd.c
+++ b/log/logd.c
@@ -31,8 +31,16 @@ static struct blob_buf b;
 static struct ubus_auto_conn conn;
 static LIST_HEAD(clients);
 
-static const struct blobmsg_policy read_policy =
-       { .name = "lines", .type = BLOBMSG_TYPE_INT32 };
+enum {
+       READ_LINES,
+       READ_STREAM,
+       __READ_MAX
+};
+
+static const struct blobmsg_policy read_policy[__READ_MAX] = {
+       [READ_LINES] = { .name = "lines", .type = BLOBMSG_TYPE_INT32 },
+       [READ_STREAM] = { .name = "stream", .type = BLOBMSG_TYPE_BOOL },
+};
 
 static const struct blobmsg_policy write_policy =
        { .name = "event", .type = BLOBMSG_TYPE_STRING };
@@ -60,48 +68,68 @@ static void client_notify_state(struct ustream *s)
        client_close(s);
 }
 
+static void
+log_fill_msg(struct blob_buf *b, struct log_head *l)
+{
+       blob_buf_init(b, 0);
+       blobmsg_add_string(b, "msg", l->data);
+       blobmsg_add_u32(b, "id", l->id);
+       blobmsg_add_u32(b, "priority", l->priority);
+       blobmsg_add_u32(b, "source", l->source);
+       blobmsg_add_u64(b, "time", l->ts.tv_sec * 1000LL);
+}
+
 static int
 read_log(struct ubus_context *ctx, struct ubus_object *obj,
                struct ubus_request_data *req, const char *method,
                struct blob_attr *msg)
 {
        struct client *cl;
-       struct blob_attr *tb;
+       struct blob_attr *tb[__READ_MAX];
        struct log_head *l;
        int count = 0;
        int fds[2];
        int ret;
+       bool stream = true;
 
        if (msg) {
-               blobmsg_parse(&read_policy, 1, &tb, blob_data(msg), blob_len(msg));
-               if (tb)
-                       count = blobmsg_get_u32(tb);
+               blobmsg_parse(read_policy, __READ_MAX, tb, blob_data(msg), blob_len(msg));
+               if (tb[READ_LINES])
+                       count = blobmsg_get_u32(tb[READ_LINES]);
+               if (tb[READ_STREAM])
+                       stream = blobmsg_get_bool(tb[READ_STREAM]);
        }
+       if (!stream)
+               count = 100;
 
        if (pipe(fds) == -1) {
                fprintf(stderr, "logd: failed to create pipe: %s\n", strerror(errno));
                return -1;
        }
-       ubus_request_set_fd(ctx, req, fds[0]);
-       cl = calloc(1, sizeof(*cl));
-       cl->s.stream.notify_state = client_notify_state;
-       cl->fd = fds[1];
-       ustream_fd_init(&cl->s, cl->fd);
-       list_add(&cl->list, &clients);
+
        l = log_list(count, NULL);
-       while ((!tb || count) && l) {
-               blob_buf_init(&b, 0);
-               blobmsg_add_string(&b, "msg", l->data);
-               blobmsg_add_u32(&b, "id", l->id);
-               blobmsg_add_u32(&b, "priority", l->priority);
-               blobmsg_add_u32(&b, "source", l->source);
-               blobmsg_add_u64(&b, "time", l->ts.tv_sec * 1000LL);
-               l = log_list(count, l);
-               ret = ustream_write(&cl->s.stream, (void *) b.head, blob_len(b.head) + sizeof(struct blob_attr), false);
-               blob_buf_free(&b);
-               if (ret < 0)
-                       break;
+       if (stream) {
+               ubus_request_set_fd(ctx, req, fds[0]);
+               cl = calloc(1, sizeof(*cl));
+               cl->s.stream.notify_state = client_notify_state;
+               cl->fd = fds[1];
+               ustream_fd_init(&cl->s, cl->fd);
+               list_add(&cl->list, &clients);
+               while ((!tb[READ_LINES] || count) && l) {
+                       log_fill_msg(&b, l);
+                       l = log_list(count, l);
+                       ret = ustream_write(&cl->s.stream, (void *) b.head, blob_len(b.head) + sizeof(struct blob_attr), false);
+                       if (ret < 0)
+                               break;
+               }
+       } else {
+               while ((!tb[READ_LINES] || count) && l) {
+                       log_fill_msg(&b, l);
+                       ubus_send_reply(ctx, req, b.head);
+                       l = log_list(count, l);
+               }
        }
+       blob_buf_free(&b);
        return 0;
 }
 
@@ -125,7 +153,7 @@ write_log(struct ubus_context *ctx, struct ubus_object *obj,
 }
 
 static const struct ubus_method log_methods[] = {
-       { .name = "read", .handler = read_log, .policy = &read_policy, .n_policy = 1 },
+       UBUS_METHOD("read", read_log, read_policy),
        { .name = "write", .handler = write_log, .policy = &write_policy, .n_policy = 1 },
 };
 

diff --git a/log/logread.c b/log/logread.c
index 83b74b1f6b752c925d1f1a295062b1104da9ef15..676bb82b18be886a3cf14a66db197ae9c7b1a0f2 100644 (file)
--- a/log/logread.c
+++ b/log/logread.c
@@ -313,6 +313,7 @@ int main(int argc, char **argv)
                }
 
                blob_buf_init(&b, 0);
+               blobmsg_add_u8(&b, "stream", 1);
                if (lines)
                        blobmsg_add_u32(&b, "lines", lines);
                else if (log_follow)