Pau Espin Pedrol | 9201677 | 2019-03-18 17:24:34 +0100 | [diff] [blame] | 1 | /* Simple Osmocom System Monitor (osysmon): Support for monitoring through shell commands */ |
| 2 | |
| 3 | /* (C) 2019 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de> |
| 4 | * All Rights Reserved. |
| 5 | * Author: Pau Espin Pedrol <pespin@sysmocom.de> |
| 6 | * |
| 7 | * SPDX-License-Identifier: GPL-2.0+ |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License as published by |
| 11 | * the Free Software Foundation; either version 2 of the License, or |
| 12 | * (at your option) any later version. |
| 13 | * |
| 14 | * This program is distributed in the hope that it will be useful, |
| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | * GNU General Public License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU General Public License |
| 20 | * along with this program; if not, write to the Free Software |
| 21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, |
| 22 | * MA 02110-1301, USA. |
| 23 | */ |
| 24 | |
| 25 | #include <string.h> |
| 26 | #include <stdio.h> |
| 27 | #include <errno.h> |
| 28 | #include <sys/sysinfo.h> |
| 29 | |
| 30 | #include <osmocom/vty/vty.h> |
| 31 | #include <osmocom/vty/command.h> |
| 32 | |
| 33 | #include "osysmon.h" |
| 34 | #include "value_node.h" |
| 35 | |
| 36 | /*********************************************************************** |
| 37 | * Data model |
| 38 | ***********************************************************************/ |
| 39 | |
| 40 | struct osysmon_shellcmd { |
| 41 | struct llist_head list; |
| 42 | struct { |
| 43 | const char *name; |
| 44 | const char *cmd; |
| 45 | } cfg; |
| 46 | }; |
| 47 | |
| 48 | static struct osysmon_shellcmd *osysmon_shellcmd_find(const char *name) |
| 49 | { |
| 50 | struct osysmon_shellcmd *oc; |
| 51 | |
| 52 | llist_for_each_entry(oc, &g_oss->shellcmds, list) { |
| 53 | if (!strcmp(oc->cfg.name, name)) |
| 54 | return oc; |
| 55 | } |
| 56 | return NULL; |
| 57 | } |
| 58 | |
| 59 | static struct osysmon_shellcmd *osysmon_shellcmd_add(const char *name, const char *cmd) |
| 60 | { |
| 61 | struct osysmon_shellcmd *oc; |
| 62 | |
| 63 | if (osysmon_shellcmd_find(name)) |
| 64 | return NULL; |
| 65 | |
| 66 | oc = talloc_zero(g_oss, struct osysmon_shellcmd); |
| 67 | OSMO_ASSERT(oc); |
| 68 | oc->cfg.name = talloc_strdup(oc, name); |
| 69 | oc->cfg.cmd = talloc_strdup(oc, cmd); |
| 70 | llist_add_tail(&oc->list, &g_oss->shellcmds); |
| 71 | return oc; |
| 72 | } |
| 73 | |
| 74 | static void osysmon_shellcmd_destroy(struct osysmon_shellcmd *oc) |
| 75 | { |
| 76 | llist_del(&oc->list); |
| 77 | talloc_free(oc); |
| 78 | } |
| 79 | |
| 80 | static void osysmon_shellcmd_run(struct osysmon_shellcmd *oc, struct value_node *parent) |
| 81 | { |
| 82 | char buf[512]; |
| 83 | FILE *f; |
| 84 | char *p = buf; |
| 85 | long offset = 0; |
| 86 | |
| 87 | f = popen(oc->cfg.cmd, "r"); |
| 88 | if (!f) { |
| 89 | snprintf(buf, sizeof(buf), "<popen failed (%d)>", errno); |
| 90 | value_node_add(parent, oc->cfg.name, buf); |
| 91 | return; |
| 92 | } |
| 93 | |
| 94 | while ((offset = fread(p, 1, sizeof(buf) - 1 - (p - buf), f)) != 0) { |
| 95 | p += offset; |
| 96 | *p = '\0'; |
| 97 | } |
| 98 | |
| 99 | pclose(f); |
| 100 | |
| 101 | if (buf != p) { |
| 102 | if (*(p - 1) == '\n') /* Remove final new line if exists */ |
| 103 | *(p - 1) = '\0'; |
| 104 | value_node_add(parent, oc->cfg.name, buf); |
| 105 | } else { |
| 106 | value_node_add(parent, oc->cfg.name, "<EMPTY>"); |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | /*********************************************************************** |
| 111 | * VTY |
| 112 | ***********************************************************************/ |
| 113 | |
| 114 | #define CMD_STR "Configure a shell command to be executed\n" |
| 115 | DEFUN(cfg_shellcmd, cfg_shellcmd_cmd, |
| 116 | "shellcmd NAME .TEXT", |
| 117 | CMD_STR "Name of this shell command snippet\n" "Command to run\n") |
| 118 | { |
| 119 | struct osysmon_shellcmd *oc; |
| 120 | char *concat = argv_concat(argv, argc, 1); |
| 121 | oc = osysmon_shellcmd_add(argv[0], concat); |
| 122 | talloc_free(concat); |
| 123 | if (!oc) { |
| 124 | vty_out(vty, "Couldn't add shell cmd, maybe it exists?%s", VTY_NEWLINE); |
| 125 | return CMD_WARNING; |
| 126 | } |
| 127 | return CMD_SUCCESS; |
| 128 | } |
| 129 | |
| 130 | DEFUN(cfg_no_shellcmd, cfg_no_shellcmd_cmd, |
| 131 | "no shellcmd NAME", |
| 132 | NO_STR CMD_STR "Name of this shell command snippet\n") |
| 133 | { |
| 134 | struct osysmon_shellcmd *oc; |
| 135 | oc = osysmon_shellcmd_find(argv[0]); |
| 136 | if (!oc) { |
| 137 | vty_out(vty, "Cannot find shell cmd for '%s'%s", argv[0], VTY_NEWLINE); |
| 138 | return CMD_WARNING; |
| 139 | } |
| 140 | osysmon_shellcmd_destroy(oc); |
| 141 | return CMD_SUCCESS; |
| 142 | } |
| 143 | |
| 144 | |
| 145 | static void osysmon_shellcmd_vty_init(void) |
| 146 | { |
| 147 | install_element(CONFIG_NODE, &cfg_shellcmd_cmd); |
| 148 | install_element(CONFIG_NODE, &cfg_no_shellcmd_cmd); |
| 149 | } |
| 150 | |
| 151 | /*********************************************************************** |
| 152 | * Runtime Code |
| 153 | ***********************************************************************/ |
| 154 | |
| 155 | /* called once on startup before config file parsing */ |
| 156 | int osysmon_shellcmd_init() |
| 157 | { |
| 158 | osysmon_shellcmd_vty_init(); |
| 159 | return 0; |
| 160 | } |
| 161 | |
| 162 | /* called periodically */ |
| 163 | int osysmon_shellcmd_poll(struct value_node *parent) |
| 164 | { |
| 165 | struct value_node *vn_file; |
| 166 | struct osysmon_shellcmd *oc; |
| 167 | |
| 168 | vn_file = value_node_add(parent, "shellcmd", NULL); |
| 169 | |
| 170 | llist_for_each_entry(oc, &g_oss->shellcmds, list) |
| 171 | osysmon_shellcmd_run(oc, vn_file); |
| 172 | |
| 173 | return 0; |
| 174 | } |