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| 1 | +From ee47eb11cbfc37600a59f06ae153da5c2c486fea Mon Sep 17 00:00:00 2001 |
| 2 | +From: liuh-80 <liuh@microsoft.com> |
| 3 | +Date: Tue, 25 Oct 2022 10:34:08 +0800 |
| 4 | +Subject: [PATCH] Send remote address in TACACS+ authorization message. |
| 5 | + |
| 6 | +--- |
| 7 | + nss_tacplus.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++++++- |
| 8 | + 1 file changed, 76 insertions(+), 1 deletion(-) |
| 9 | + |
| 10 | +diff --git a/nss_tacplus.c b/nss_tacplus.c |
| 11 | +index 2de00a6..048745a 100644 |
| 12 | +--- a/nss_tacplus.c |
| 13 | ++++ b/nss_tacplus.c |
| 14 | +@@ -33,12 +33,20 @@ |
| 15 | + #include <ctype.h> |
| 16 | + #include <netdb.h> |
| 17 | + #include <nss.h> |
| 18 | ++#include <limits.h> |
| 19 | + |
| 20 | + #include <libtac/libtac.h> |
| 21 | + |
| 22 | + #define MIN_TACACS_USER_PRIV (1) |
| 23 | + #define MAX_TACACS_USER_PRIV (15) |
| 24 | + |
| 25 | ++#define GET_ENV_VARIABLE_OK 0 |
| 26 | ++#define GET_ENV_VARIABLE_NOT_FOUND 1 |
| 27 | ++#define GET_ENV_VARIABLE_INCORRECT_FORMAT 2 |
| 28 | ++#define GET_ENV_VARIABLE_NOT_ENOUGH_BUFFER 3 |
| 29 | ++#define GET_REMOTE_ADDRESS_OK 0 |
| 30 | ++#define GET_REMOTE_ADDRESS_FAILED 1 |
| 31 | ++ |
| 32 | + static const char *nssname = "nss_tacplus"; /* for syslogs */ |
| 33 | + static const char *config_file = "/etc/tacplus_nss.conf"; |
| 34 | + static const char *user_conf = "/etc/tacplus_user"; |
| 35 | +@@ -717,6 +725,66 @@ connect_tacacs(struct tac_attrib **attr, int srvr) |
| 36 | + return fd; |
| 37 | + } |
| 38 | + |
| 39 | ++/* |
| 40 | ++ * Get environment variable first part by name and delimiters |
| 41 | ++ */ |
| 42 | ++int get_environment_variable_first_part(char* dst, socklen_t size, const char* name, const char* delimiters) |
| 43 | ++{ |
| 44 | ++ memset(dst, 0, size); |
| 45 | ++ |
| 46 | ++ const char* variable = getenv(name); |
| 47 | ++ if (variable == NULL) { |
| 48 | ++ if (debug) { |
| 49 | ++ syslog(LOG_DEBUG, "%s: can't get environment variable %s, errno=%d", nssname, name, errno); |
| 50 | ++ } |
| 51 | ++ |
| 52 | ++ return GET_ENV_VARIABLE_NOT_FOUND; |
| 53 | ++ } |
| 54 | ++ |
| 55 | ++ char* context = NULL; |
| 56 | ++ char* first_part = strtok_r((char *)variable, delimiters, &context); |
| 57 | ++ if (first_part == NULL) { |
| 58 | ++ if (debug) { |
| 59 | ++ syslog(LOG_DEBUG, "%s: can't split %s by delimiters %s", nssname, variable, delimiters); |
| 60 | ++ } |
| 61 | ++ |
| 62 | ++ return GET_ENV_VARIABLE_INCORRECT_FORMAT; |
| 63 | ++ } |
| 64 | ++ |
| 65 | ++ int first_part_len = strlen(first_part); |
| 66 | ++ if (first_part_len >= size) { |
| 67 | ++ if (debug) { |
| 68 | ++ syslog(LOG_DEBUG, "%s: dest buffer size %d not enough for %s", nssname, size, first_part); |
| 69 | ++ } |
| 70 | ++ |
| 71 | ++ return GET_ENV_VARIABLE_NOT_ENOUGH_BUFFER; |
| 72 | ++ } |
| 73 | ++ |
| 74 | ++ strncpy(dst, first_part, size); |
| 75 | ++ if (debug) { |
| 76 | ++ syslog(LOG_DEBUG, "%s: remote address=%s", nssname, dst); |
| 77 | ++ } |
| 78 | ++ |
| 79 | ++ return GET_ENV_VARIABLE_OK; |
| 80 | ++} |
| 81 | ++ |
| 82 | ++/* |
| 83 | ++ * Get current SSH session remote address from environment variable |
| 84 | ++ */ |
| 85 | ++int get_remote_address(char* dst, socklen_t size) |
| 86 | ++{ |
| 87 | ++ // SSHD will create environment variable SSH_CONNECTION after user session created. |
| 88 | ++ if (get_environment_variable_first_part(dst, size, "SSH_CONNECTION", " ") == GET_ENV_VARIABLE_OK) { |
| 89 | ++ return GET_REMOTE_ADDRESS_OK; |
| 90 | ++ } |
| 91 | ++ |
| 92 | ++ // Before user session created, SSHD will create environment variable SSH_CLIENT_IPADDR_PORT. |
| 93 | ++ if (get_environment_variable_first_part(dst, size, "SSH_CLIENT_IPADDR_PORT", " ") == GET_ENV_VARIABLE_OK) { |
| 94 | ++ return GET_REMOTE_ADDRESS_OK; |
| 95 | ++ } |
| 96 | ++ |
| 97 | ++ return GET_REMOTE_ADDRESS_FAILED; |
| 98 | ++} |
| 99 | + |
| 100 | + /* |
| 101 | + * lookup the user on a TACACS server. Returns 0 on successful lookup, else 1 |
| 102 | +@@ -735,6 +803,13 @@ lookup_tacacs_user(struct pwbuf *pb) |
| 103 | + int ret = 1, done = 0; |
| 104 | + struct tac_attrib *attr; |
| 105 | + int tac_fd, srvr; |
| 106 | ++ char remote_addr[INET6_ADDRSTRLEN]; |
| 107 | ++ const char* current_tty = getenv("SSH_TTY"); |
| 108 | ++ |
| 109 | ++ int result = get_remote_address(remote_addr, sizeof(remote_addr)); |
| 110 | ++ if ((result != GET_REMOTE_ADDRESS_OK) && debug) { |
| 111 | ++ syslog(LOG_DEBUG, "%s: can't get remote address from environment variable, result=%d", nssname, result); |
| 112 | ++ } |
| 113 | + |
| 114 | + for(srvr=0; srvr < tac_srv_no && !done; srvr++) { |
| 115 | + arep.msg = NULL; |
| 116 | +@@ -748,7 +823,7 @@ lookup_tacacs_user(struct pwbuf *pb) |
| 117 | + tac_ntop(tac_srv[srvr].addr->ai_addr) : "unknown", tac_fd); |
| 118 | + continue; |
| 119 | + } |
| 120 | +- ret = tac_author_send(tac_fd, pb->name, "", "", attr); |
| 121 | ++ ret = tac_author_send(tac_fd, pb->name, current_tty != NULL ? (char *)current_tty : "", remote_addr, attr); |
| 122 | + if(ret < 0) { |
| 123 | + if(debug) |
| 124 | + syslog(LOG_WARNING, "%s: TACACS+ server %s send failed (%d) for" |
| 125 | +-- |
| 126 | +2.37.1.windows.1 |
| 127 | + |
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