| /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <stdio.h> |
| #include <unistd.h> |
| |
| #include "af-list.h" |
| #include "fd-util.h" |
| #include "fileio.h" |
| #include "log.h" |
| #include "macro.h" |
| #include "path-util.h" |
| #include "socket-util.h" |
| #include "string-util.h" |
| #include "sysctl-util.h" |
| |
| char *sysctl_normalize(char *s) { |
| char *n; |
| |
| n = strpbrk(s, "/."); |
| |
| /* If the first separator is a slash, the path is |
| * assumed to be normalized and slashes remain slashes |
| * and dots remains dots. */ |
| |
| if (n && *n == '.') |
| /* Dots become slashes and slashes become dots. Fun. */ |
| do { |
| if (*n == '.') |
| *n = '/'; |
| else |
| *n = '.'; |
| |
| n = strpbrk(n + 1, "/."); |
| } while (n); |
| |
| path_simplify(s); |
| |
| /* Kill the leading slash, but keep the first character of the string in the same place. */ |
| if (s[0] == '/' && s[1] != 0) |
| memmove(s, s+1, strlen(s)); |
| |
| return s; |
| } |
| |
| int sysctl_write(const char *property, const char *value) { |
| char *p; |
| |
| assert(property); |
| assert(value); |
| |
| p = strjoina("/proc/sys/", property); |
| |
| path_simplify(p); |
| if (!path_is_normalized(p)) |
| return -EINVAL; |
| |
| log_debug("Setting '%s' to '%s'", p, value); |
| |
| return write_string_file(p, value, WRITE_STRING_FILE_VERIFY_ON_FAILURE | WRITE_STRING_FILE_DISABLE_BUFFER | WRITE_STRING_FILE_SUPPRESS_REDUNDANT_VIRTUAL); |
| } |
| |
| int sysctl_writef(const char *property, const char *format, ...) { |
| _cleanup_free_ char *v = NULL; |
| va_list ap; |
| int r; |
| |
| va_start(ap, format); |
| r = vasprintf(&v, format, ap); |
| va_end(ap); |
| |
| if (r < 0) |
| return -ENOMEM; |
| |
| return sysctl_write(property, v); |
| } |
| |
| int sysctl_write_ip_property(int af, const char *ifname, const char *property, const char *value) { |
| const char *p; |
| |
| assert(property); |
| assert(value); |
| |
| if (!IN_SET(af, AF_INET, AF_INET6)) |
| return -EAFNOSUPPORT; |
| |
| if (ifname) { |
| if (!ifname_valid_full(ifname, IFNAME_VALID_SPECIAL)) |
| return -EINVAL; |
| |
| p = strjoina("net/", af_to_ipv4_ipv6(af), "/conf/", ifname, "/", property); |
| } else |
| p = strjoina("net/", af_to_ipv4_ipv6(af), "/", property); |
| |
| return sysctl_write(p, value); |
| } |
| |
| int sysctl_read(const char *property, char **ret) { |
| char *p; |
| int r; |
| |
| assert(property); |
| |
| p = strjoina("/proc/sys/", property); |
| |
| path_simplify(p); |
| if (!path_is_normalized(p)) /* Filter out attempts to write to /proc/sys/../../…, just in case */ |
| return -EINVAL; |
| |
| r = read_full_virtual_file(p, ret, NULL); |
| if (r < 0) |
| return r; |
| if (ret) |
| delete_trailing_chars(*ret, NEWLINE); |
| |
| return r; |
| } |
| |
| int sysctl_read_ip_property(int af, const char *ifname, const char *property, char **ret) { |
| const char *p; |
| |
| assert(property); |
| |
| if (!IN_SET(af, AF_INET, AF_INET6)) |
| return -EAFNOSUPPORT; |
| |
| if (ifname) { |
| if (!ifname_valid_full(ifname, IFNAME_VALID_SPECIAL)) |
| return -EINVAL; |
| |
| p = strjoina("net/", af_to_ipv4_ipv6(af), "/conf/", ifname, "/", property); |
| } else |
| p = strjoina("net/", af_to_ipv4_ipv6(af), "/", property); |
| |
| return sysctl_read(p, ret); |
| } |