Render a scene with openGL

I've to render a scene that include various mesh with openGL. the meshes are defined like this:

struct Mesh {
frame3f         frame;      // frame
vector<vec3f>   pos;        // vertex position
vector<vec3f>   norm;       // vertex normal
vector<vec2f>   texcoord;   // vertex texcture coordinates
vector<vec3i>   triangle;   // triangle
vector<vec4i>   quad;       // quad
Material*       mat;        // material}

the mesh can be made of triangles and quads, I try to render the vertex with this code:

for (auto mesh : scene->meshes)
{
    // bind material kd, ks, n
    glVertexAttrib3f(material_kd_loc, mesh->mat->kd.x, mesh->mat->kd.y, mesh->mat->kd.z);
    glVertexAttrib3f(material_ks_loc, mesh->mat->ks.x, mesh->mat->ks.y, mesh->mat->ks.z);
    glVertexAttrib1f(material_n_loc, mesh->mat->n);

    // bind mesh frame - use frame_to_matrix
    mat4f mesh_mat = frame_to_matrix(mesh->frame);
    glUniformMatrix4fv(mesh_frame_loc, 1, GL_TRUE, &mesh_mat[0][0]);

    // enable vertex attributes arrays
    glEnableVertexAttribArray(0);
    glEnableVertexAttribArray(1);

    //and set up pointers to the mesh data
    glVertexAttribPointer(vertex_pos_loc, mesh->pos.size(), GL_FLOAT, GL_FALSE, 0, mesh->pos.data());
    glVertexAttribPointer(vertex_norm_loc, mesh->norm.size(), GL_FLOAT, GL_TRUE, 0, mesh->norm.data());

    // draw triangles and quads
    if (mesh->triangle.size() != 0){

        glDrawElements(GL_TRIANGLES, mesh->pos.size(), GL_UNSIGNED_INT, mesh->triangle.data());
    }
    if (mesh->quad.size() != 0){
        glDrawElements(GL_QUADS, mesh->pos.size(), GL_UNSIGNED_INT, mesh->quad.data());

    }
    // disable vertex attribute arrays
    glDisableVertexAttribArray(0);
    glDisableVertexAttribArray(1);
}

} this is what i draw (don't care about colors as i don't calculate them yet)

this is what i should see if my code is correct

anyone as an idea of where is the error?

look like the opengl function wants the total number of vertecx to be written and not just the number of different vertex. so:

glDrawElements(GL_TRIANGLES, mesh->triangle.size()*3, GL_UNSIGNED_INT, mesh->triangle.data());
glDrawElements(GL_QUADS, mesh->quad.size()*4, GL_UNSIGNED_INT, mesh->quad.data());