diff options
| -rw-r--r-- | toys/pending/sysctl.c | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/toys/pending/sysctl.c b/toys/pending/sysctl.c new file mode 100644 index 00000000..74e7dee1 --- /dev/null +++ b/toys/pending/sysctl.c @@ -0,0 +1,208 @@ +/* sysctl.c - A utility to read and manipulate the sysctl parameters. + * + * Copyright 2014 Bilal Qureshi <bilal.jmi@gmail.com> + * Copyright 2014 Kyungwan Han <asura321@gmail.com> + * + * No Standard + +USE_SYSCTL(NEWTOY(sysctl, "^neNqwpaA[!ap][!aq][!aw][+aA]", TOYFLAG_USR|TOYFLAG_BIN)) + +config SYSCTL + bool "sysctl" + default n + help + usage: sysctl [OPTIONS] [KEY[=VALUE]]... + + -a, A Show all values + -e Don't warn about unknown keys + -N Show only key names + -n Show only key values + -p FILE Set values from FILE (default /etc/sysctl.conf) + -q Set values silently + -w Set values +*/ +#define FOR_sysctl +#include "toys.h" + +#define PROC_SYS_DIR "/proc/sys" +#define MAX_BYTES_LINE 1024 + +static void parse_key_name_value(char *param, char **key_name, char **key_value) +{ + char *name, *value; + + if (!(name = strchr(param, '='))) goto show_error_msg; + value = name; + value++; + if (!(*value)) goto show_error_msg; + *name = '\0'; + *key_name = param; + *key_value = value; + return; +show_error_msg: + error_msg("error: '%s' must be of the form name=value", param); +} + +static void replace_char(char *str, char old, char new) +{ + char *tmp = str; + + for (; *tmp; tmp++) + if (*tmp == old) *tmp = new; +} + +static void handle_file_error(char *key_name) +{ + replace_char(key_name, '/', '.'); + if (errno == ENOENT) { + if (!(toys.optflags & FLAG_e)) + error_msg("error: '%s' is an unknown key", key_name); + else toys.exitval = 1; + } else perror_msg("error: %s key '%s'", (toys.optflags & FLAG_w) ? + "setting" : "reading", key_name); +} + +static void write_to_file(char *fpath, char *key_name, char *key_value) +{ + int fd; + + replace_char(key_name, '.', '/'); + sprintf(toybuf, "%s/%s", fpath, key_name); + if ((fd = open(toybuf, O_WRONLY)) < 0) { + handle_file_error(key_name); + return; + } + xwrite(fd, key_value, strlen(key_value)); + xclose(fd); + if (!(toys.optflags & FLAG_q)) { + replace_char(key_name, '/', '.'); + if (toys.optflags & FLAG_N) xprintf("%s\n", key_name); + else if (toys.optflags & FLAG_n) xprintf("%s\n", key_value); + else xprintf("%s = %s\n", key_name, key_value); + } +} + +static char *get_key_value(char *buff, int *offset) +{ + char *line, *tmp = (char *) (buff + *offset); + int index = 0, multiplier = 1; + + if (!(*tmp)) return NULL; + line = (char *) xmalloc(sizeof(char) * MAX_BYTES_LINE); + for (; *tmp != '\n'; tmp++) { + line[index++] = *tmp; + if (MAX_BYTES_LINE == index) { // buffer overflow + multiplier++; + line = (char *) xrealloc(line, multiplier * MAX_BYTES_LINE); + } + } + line[index++] = '\0'; + *offset += index; + return line; +} + +// Open file for each and every key name and read file contents +void read_key_values(char *fpath) +{ + char *key_value, *fdata, *key_name, *tmp = xstrdup(fpath); + int offset = 0; + + key_name = (tmp + strlen(PROC_SYS_DIR) + 1); + replace_char(key_name, '/', '.'); + if (!(fdata = readfile(fpath, NULL, 0))) { + handle_file_error(key_name); + free(tmp); + return; + } + if (toys.optflags & FLAG_N) { + xprintf("%s\n", key_name); + free(tmp); + free(fdata); + return; + } + for (; (key_value = get_key_value(fdata, &offset)); free(key_value)) { + if (!(toys.optflags & FLAG_q)) { + if (!(toys.optflags & FLAG_n)) xprintf("%s = ", key_name); + xprintf("%s\n", key_value); + } + } + free(tmp); + free(fdata); +} + +static void trim_spaces(char **param) +{ + int len = 0; + char *str = *param, *p_start = str, *p_end; + + if (p_start) { // start pointer to string + p_end = str + strlen(str) - 1; // end pointer to string + while (*p_start == ' ') p_start++; + str = p_start; + while (*p_end == ' ') p_end--; + p_end++; + *p_end = '\0'; + len = (int) (p_end - str) + 1; + memmove(*param, str, len); + } +} + +// Read config file and write values to there corresponding key name files +static void read_config_file(char *fname) +{ + char *line, *name = NULL, *value = NULL; + int fd = xopen(fname, O_RDONLY); + + for (; (line = get_line(fd)); free(line), name = NULL, value = NULL) { + char *ptr = line; + + while (*ptr == ' ' || *ptr == '\t') ptr++; + if (*ptr != '#' && *ptr != ';' && *ptr !='\n' && *ptr) { + parse_key_name_value(ptr, &name, &value); + trim_spaces(&name); + trim_spaces(&value); + if (name && value) write_to_file(PROC_SYS_DIR, name, value); + } + } + xclose(fd); +} + +static int do_process(struct dirtree *dt) +{ + char *fpath; + + if (!dirtree_notdotdot(dt)) return 0; // Skip . and .. + if (S_ISDIR(dt->st.st_mode)) return DIRTREE_RECURSE; + if ((fpath = dirtree_path(dt, 0))) { + read_key_values(fpath); + free(fpath); + } + return 0; +} + +void sysctl_main() +{ + char *name = NULL, *value = NULL, **args = NULL; + + if (toys.optflags & FLAG_a) { + dirtree_read(PROC_SYS_DIR, do_process); + return; + } + if (toys.optflags & FLAG_p) { + if (*toys.optargs) read_config_file(*toys.optargs); + else read_config_file("/etc/sysctl.conf"); + return; + } + if (toys.optflags & FLAG_w) { + for (args = toys.optargs; *args; args++, name = NULL, value = NULL) { + parse_key_name_value(*args, &name, &value); + if (name && value) write_to_file(PROC_SYS_DIR, name, value); + } + return; + } + for (args = toys.optargs; *args; args++) { + replace_char(*args, '.', '/'); + sprintf(toybuf, "%s/%s", PROC_SYS_DIR, *args); + read_key_values(toybuf); + } +} |