FD.io VPP  v17.07-30-g839fa73
Vector Packet Processing
plugin.c
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1 /*
2  * Copyright (c) 2015 Cisco and/or its affiliates.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at:
6  *
7  * http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 /*
16  * plugin.c: plugin handling
17  */
18 
19 #include <vat/vat.h>
20 #include <vat/plugin.h>
21 #include <dlfcn.h>
22 #include <dirent.h>
23 
25 
26 static int
28 {
29  void *handle, *register_handle;
30  clib_error_t *(*fp) (vat_main_t *);
31  clib_error_t *error;
32 
33  handle = dlopen ((char *) pi->name, RTLD_LAZY);
34 
35  /*
36  * Note: this can happen if the plugin has an undefined symbol reference,
37  * so print a warning. Otherwise, the poor slob won't know what happened.
38  * Ask me how I know that...
39  */
40  if (handle == 0)
41  {
42  clib_warning ("%s", dlerror ());
43  return -1;
44  }
45 
46  pi->handle = handle;
47 
48  register_handle = dlsym (pi->handle, "vat_plugin_register");
49  if (register_handle == 0)
50  return 0;
51 
52  fp = register_handle;
53 
54  error = (*fp) (pm->vat_main);
55 
56  if (error)
57  {
58  clib_error_report (error);
59  dlclose (handle);
60  return 1;
61  }
62 
63  clib_warning ("Loaded plugin: %s", pi->name);
64 
65  return 0;
66 }
67 
68 static u8 **
70 {
71  int i;
72  u8 **rv = 0;
73  u8 *path = pm->plugin_path;
74  u8 *this = 0;
75 
76  for (i = 0; i < vec_len (pm->plugin_path); i++)
77  {
78  if (path[i] != ':')
79  {
80  vec_add1 (this, path[i]);
81  continue;
82  }
83  vec_add1 (this, 0);
84  vec_add1 (rv, this);
85  this = 0;
86  }
87  if (this)
88  {
89  vec_add1 (this, 0);
90  vec_add1 (rv, this);
91  }
92  return rv;
93 }
94 
95 int
97 {
98  DIR *dp;
99  struct dirent *entry;
100  struct stat statb;
101  uword *p;
102  plugin_info_t *pi;
103  u8 **plugin_path;
104  int i;
105 
106  plugin_path = split_plugin_path (pm);
107 
108  for (i = 0; i < vec_len (plugin_path); i++)
109  {
110  dp = opendir ((char *) plugin_path[i]);
111 
112  if (dp == 0)
113  continue;
114 
115  while ((entry = readdir (dp)))
116  {
117  u8 *plugin_name;
118 
119  if (pm->plugin_name_filter)
120  {
121  int j;
122  for (j = 0; j < vec_len (pm->plugin_name_filter); j++)
123  if (entry->d_name[j] != pm->plugin_name_filter[j])
124  goto next;
125  }
126 
127  plugin_name = format (0, "%s/%s%c", plugin_path[i],
128  entry->d_name, 0);
129 
130  /* unreadable */
131  if (stat ((char *) plugin_name, &statb) < 0)
132  {
133  ignore:
134  vec_free (plugin_name);
135  continue;
136  }
137 
138  /* a dir or other things which aren't plugins */
139  if (!S_ISREG (statb.st_mode))
140  goto ignore;
141 
142  p = hash_get_mem (pm->plugin_by_name_hash, plugin_name);
143  if (p == 0)
144  {
145  vec_add2 (pm->plugin_info, pi, 1);
146  pi->name = plugin_name;
147  pi->file_info = statb;
148 
149  if (load_one_plugin (pm, pi))
150  {
151  vec_free (plugin_name);
152  _vec_len (pm->plugin_info) = vec_len (pm->plugin_info) - 1;
153  continue;
154  }
155  memset (pi, 0, sizeof (*pi));
156  hash_set_mem (pm->plugin_by_name_hash, plugin_name,
157  pi - pm->plugin_info);
158  }
159  next:
160  ;
161  }
162  closedir (dp);
163  vec_free (plugin_path[i]);
164  }
165  vec_free (plugin_path);
166  return 0;
167 }
168 
169 #define QUOTE_(x) #x
170 #define QUOTE(x) QUOTE_(x)
171 
172 /*
173  * Load plugins from /usr/lib/vpp_api_test_plugins by default
174  */
175 char *vat_plugin_path = "/usr/lib/vpp_api_test_plugins";
176 
178 
179 int
180 vat_plugin_init (vat_main_t * vam)
181 {
183 
184 
185  pm->plugin_path = format (0, "%s%c", vat_plugin_path, 0);
187  pm->plugin_name_filter = format (0, "%s%c", vat_plugin_name_filter, 0);
188 
189  pm->plugin_by_name_hash = hash_create_string (0, sizeof (uword));
190  pm->vat_main = vam;
191 
192  return vat_load_new_plugins (pm);
193 }
194 
195 /*
196  * fd.io coding-style-patch-verification: ON
197  *
198  * Local Variables:
199  * eval: (c-set-style "gnu")
200  * End:
201  */
u8 * plugin_path
Definition: plugin.h:96
sll srl srl sll sra u16x4 i
Definition: vector_sse2.h:337
u8 * plugin_name_filter
Definition: plugin.h:97
char * vat_plugin_path
Definition: plugin.c:175
#define vec_add1(V, E)
Add 1 element to end of vector (unspecified alignment).
Definition: vec.h:522
#define vec_add2(V, P, N)
Add N elements to end of vector V, return pointer to new elements in P.
Definition: vec.h:561
#define hash_set_mem(h, key, value)
Definition: hash.h:274
u8 * format(u8 *s, const char *fmt,...)
Definition: format.c:419
char * vat_plugin_name_filter
Definition: plugin.c:177
u8 * name
Definition: plugin.h:71
#define hash_create_string(elts, value_bytes)
Definition: hash.h:652
static int load_one_plugin(plugin_main_t *pm, plugin_info_t *pi)
Definition: plugin.c:27
plugin_info_t * plugin_info
Definition: plugin.h:92
#define vec_free(V)
Free vector&#39;s memory (no header).
Definition: vec.h:340
#define clib_warning(format, args...)
Definition: error.h:59
static u8 ** split_plugin_path(plugin_main_t *pm)
Definition: plugin.c:69
#define clib_error_report(e)
Definition: error.h:113
u64 uword
Definition: types.h:112
void * handle
Definition: plugin.h:74
#define vec_len(v)
Number of elements in vector (rvalue-only, NULL tolerant)
unsigned char u8
Definition: types.h:56
int vat_plugin_init(vat_main_t *vam)
Definition: plugin.c:180
#define hash_get_mem(h, key)
Definition: hash.h:268
plugin_main_t vat_plugin_main
Definition: plugin.c:24
int vat_load_new_plugins(plugin_main_t *pm)
Definition: plugin.c:96
vat_main_t * vat_main
Definition: plugin.h:44
struct stat file_info
Definition: plugin.h:73
uword * plugin_by_name_hash
Definition: plugin.h:93