| 1 | // SPDX-License-Identifier: GPL-3.0-or-later |
| 2 | |
| 3 | //go:build linux |
| 4 | |
| 5 | package fail2ban |
| 6 | |
| 7 | import ( |
| 8 | "bufio" |
| 9 | "bytes" |
| 10 | "errors" |
| 11 | "fmt" |
| 12 | "strconv" |
| 13 | "strings" |
| 14 | "time" |
| 15 | ) |
| 16 | |
| 17 | func (c *Collector) collect() (map[string]int64, error) { |
| 18 | now := time.Now() |
| 19 | |
| 20 | if now.Sub(c.lastDiscoverTime) > c.discoverEvery || c.forceDiscover { |
| 21 | jails, err := c.discoverJails() |
| 22 | if err != nil { |
| 23 | return nil, err |
| 24 | } |
| 25 | c.jails = jails |
| 26 | c.lastDiscoverTime = now |
| 27 | c.forceDiscover = false |
| 28 | } |
| 29 | |
| 30 | mx := make(map[string]int64) |
| 31 | |
| 32 | if err := c.collectJails(mx); err != nil { |
| 33 | return nil, err |
| 34 | } |
| 35 | |
| 36 | return mx, nil |
| 37 | } |
| 38 | |
| 39 | func (c *Collector) discoverJails() ([]string, error) { |
| 40 | bs, err := c.exec.status() |
| 41 | if err != nil { |
| 42 | return nil, err |
| 43 | } |
| 44 | |
| 45 | jails, err := parseFail2banStatus(bs) |
| 46 | if err != nil { |
| 47 | return nil, err |
| 48 | } |
| 49 | |
| 50 | if len(jails) == 0 { |
| 51 | return nil, errors.New("no jails found") |
| 52 | } |
| 53 | |
| 54 | c.Debugf("discovered %d jails: %v", len(jails), jails) |
| 55 | |
| 56 | return jails, nil |
| 57 | } |
| 58 | |
| 59 | func (c *Collector) collectJails(mx map[string]int64) error { |
| 60 | seen := make(map[string]bool) |
| 61 | |
| 62 | for _, jail := range c.jails { |
| 63 | c.Debugf("querying status for jail '%s'", jail) |
| 64 | bs, err := c.exec.jailStatus(jail) |
| 65 | if err != nil { |
| 66 | if errors.Is(err, errJailNotExist) { |
| 67 | c.forceDiscover = true |
| 68 | continue |
| 69 | } |
| 70 | return err |
| 71 | } |
| 72 | |
| 73 | failed, banned, err := parseFail2banJailStatus(bs) |
| 74 | if err != nil { |
| 75 | return err |
| 76 | } |
| 77 | |
| 78 | if !c.seenJails[jail] { |
| 79 | c.seenJails[jail] = true |
| 80 | c.addJailCharts(jail) |
| 81 | } |
| 82 | seen[jail] = true |
| 83 | |
| 84 | px := fmt.Sprintf("jail_%s_", jail) |
| 85 | |
| 86 | mx[px+"currently_failed"] = failed |
| 87 | mx[px+"currently_banned"] = banned |
| 88 | } |
| 89 | |
| 90 | for jail := range c.seenJails { |
| 91 | if !seen[jail] { |
| 92 | delete(c.seenJails, jail) |
| 93 | c.removeJailCharts(jail) |
| 94 | } |
| 95 | } |
| 96 | |
| 97 | return nil |
| 98 | } |
| 99 | |
| 100 | func parseFail2banJailStatus(jailStatus []byte) (failed, banned int64, err error) { |
| 101 | const ( |
| 102 | failedSub = "Currently failed:" |
| 103 | bannedSub = "Currently banned:" |
| 104 | ) |
| 105 | |
| 106 | var failedFound, bannedFound bool |
| 107 | |
| 108 | sc := bufio.NewScanner(bytes.NewReader(jailStatus)) |
| 109 | |
| 110 | for sc.Scan() && !(failedFound && bannedFound) { |
| 111 | text := strings.TrimSpace(sc.Text()) |
| 112 | if text == "" { |
| 113 | continue |
| 114 | } |
| 115 | |
| 116 | if !failedFound { |
| 117 | if _, after, ok := strings.Cut(text, failedSub); ok { |
| 118 | failedFound = true |
| 119 | s := strings.TrimSpace(after) |
| 120 | if failed, err = strconv.ParseInt(s, 10, 64); err != nil { |
| 121 | return 0, 0, fmt.Errorf("failed to parse currently failed value (%s): %v", s, err) |
| 122 | } |
| 123 | } |
| 124 | } |
| 125 | if !bannedFound { |
| 126 | if _, after, ok := strings.Cut(text, bannedSub); ok { |
| 127 | bannedFound = true |
| 128 | s := strings.TrimSpace(after) |
| 129 | if banned, err = strconv.ParseInt(s, 10, 64); err != nil { |
| 130 | return 0, 0, fmt.Errorf("failed to parse currently banned value (%s): %v", s, err) |
| 131 | } |
| 132 | } |
| 133 | } |
| 134 | } |
| 135 | |
| 136 | if !failedFound || !bannedFound { |
| 137 | return 0, 0, errors.New("failed to find failed and banned values") |
| 138 | } |
| 139 | |
| 140 | return failed, banned, nil |
| 141 | } |
| 142 | |
| 143 | func parseFail2banStatus(status []byte) ([]string, error) { |
| 144 | const sub = "Jail list:" |
| 145 | |
| 146 | var jails []string |
| 147 | |
| 148 | sc := bufio.NewScanner(bytes.NewReader(status)) |
| 149 | |
| 150 | for sc.Scan() { |
| 151 | text := strings.TrimSpace(sc.Text()) |
| 152 | |
| 153 | if _, after, ok := strings.Cut(text, sub); ok { |
| 154 | s := strings.ReplaceAll(after, ",", "") |
| 155 | jails = strings.Fields(s) |
| 156 | break |
| 157 | } |
| 158 | } |
| 159 | |
| 160 | if len(jails) == 0 { |
| 161 | return nil, errors.New("failed to find jails") |
| 162 | } |
| 163 | |
| 164 | return jails, nil |
| 165 | } |