projects / packages / dhcp_probe.git / blame
| Commit | Line | Data |
|---|---|---|
| 0d9e0091 JR |
1 | ##dhcp-probe-03-drop-privs.patch - add option to change uid after setup |
| 2 | --- src/dhcp_probe.c.02 2009-08-16 12:31:22.000000000 +0300 | |
| 3 | +++ src/dhcp_probe.c 2009-08-16 13:47:29.000000000 +0300 | |
| 4 | @@ -26,6 +26,9 @@ | |
| 5 | #include "report.h" | |
| 6 | #include "utils.h" | |
| 7 | ||
| 8 | +#include <sys/types.h> | |
| 9 | +#include <pwd.h> | |
| 10 | + | |
| 11 | #ifndef lint | |
| 12 | static const char rcsid[] = "dhcp_probe version " VERSION; | |
| 13 | static const char copyright[] = "Copyright 2000-2008, The Trustees of Princeton University. All rights reserved."; | |
| 14 | @@ -50,6 +53,8 @@ | |
| 15 | int snaplen = CAPTURE_BUFSIZE; | |
| 16 | int socket_receive_timeout_feature = 0; | |
| 17 | int keep_pcap = 0; | |
| 18 | +int drop_privs = 0; | |
| 19 | +char *username = NULL; | |
| 20 | ||
| 21 | char *prog = NULL; | |
| 22 | char *logfile_name = NULL; | |
| 23 | @@ -179,6 +184,40 @@ | |
| 24 | return packets_recv; | |
| 25 | } | |
| 26 | ||
| 27 | +/* drop privileges */ | |
| 28 | +void | |
| 29 | +drop_privileges(const char *username) | |
| 30 | +{ | |
| 31 | + struct passwd *pw; | |
| 32 | + pw = getpwnam(username); | |
| 33 | + if (pw == NULL) { | |
| 34 | + report(LOG_ERR, "getpwnam: %s", get_errmsg()); | |
| 35 | + my_exit(1, 1, 1); | |
| 36 | + } | |
| 37 | + if (debug > 1) | |
| 38 | + report(LOG_INFO, "changing to uid %d gid %d", pw->pw_uid, pw->pw_gid); | |
| 39 | + | |
| 40 | + if (setregid(pw->pw_gid, pw->pw_gid)) { | |
| 41 | + report(LOG_ERR, "setregid: %s", get_errmsg()); | |
| 42 | + my_exit(1, 1, 1); | |
| 43 | + } | |
| 44 | + if (setreuid(pw->pw_uid, pw->pw_uid)) { | |
| 45 | + report(LOG_ERR, "setreuid: %s", get_errmsg()); | |
| 46 | + my_exit(1, 1, 1); | |
| 47 | + } | |
| 48 | +} | |
| 49 | + | |
| 50 | +void write_pidfile(void) | |
| 51 | +{ | |
| 52 | + FILE *pid_fp; | |
| 53 | + if ((pid_fp = open_for_writing(pid_file)) == NULL) { | |
| 54 | + report(LOG_ERR, "could not open pid file %s for writing", pid_file); | |
| 55 | + my_exit(1, 0, 1); | |
| 56 | + } else { | |
| 57 | + fprintf(pid_fp, "%d\n", (int) getpid()); | |
| 58 | + fclose(pid_fp); | |
| 59 | + } | |
| 60 | +} | |
| 61 | ||
| 62 | int | |
| 63 | main(int argc, char **argv) | |
| 64 | @@ -188,7 +227,6 @@ | |
| 65 | extern char *optarg; | |
| 66 | extern int optind, opterr, optopt; | |
| 67 | struct sigaction sa; | |
| 68 | - FILE *pid_fp; | |
| 69 | char *cwd = CWD; | |
| 70 | ||
| 71 | int write_packet_len; | |
| 72 | @@ -208,7 +246,7 @@ | |
| 73 | else | |
| 74 | prog = argv[0]; | |
| 75 | ||
| 76 | - while ((c = getopt(argc, argv, "c:d:fhkl:o:p:Q:s:Tvw:")) != EOF) { | |
| 77 | + while ((c = getopt(argc, argv, "c:d:fhkl:o:p:Q:s:Tu:vw:")) != EOF) { | |
| 78 | switch (c) { | |
| 79 | case 'c': | |
| 80 | if (optarg[0] != '/') { | |
| 81 | @@ -283,6 +321,10 @@ | |
| 82 | } | |
| 83 | break; | |
| 84 | } | |
| 85 | + case 'u': | |
| 86 | + drop_privs = 1; | |
| 87 | + username = optarg; | |
| 88 | + break; | |
| 89 | case 'T': | |
| 90 | socket_receive_timeout_feature = 1; | |
| 91 | break; | |
| 92 | @@ -351,16 +393,6 @@ | |
| 93 | my_exit(1, 0, 1); | |
| 94 | } | |
| 95 | ||
| 96 | - | |
| 97 | - /* write pid file as soon as possible after (possibly) forking */ | |
| 98 | - if ((pid_fp = open_for_writing(pid_file)) == NULL) { | |
| 99 | - report(LOG_ERR, "could not open pid file %s for writing", pid_file); | |
| 100 | - my_exit(1, 0, 1); | |
| 101 | - } else { | |
| 102 | - fprintf(pid_fp, "%d\n", (int) getpid()); | |
| 103 | - fclose(pid_fp); | |
| 104 | - } | |
| 105 | - | |
| 106 | if (! read_configfile(config_file)) { | |
| 107 | my_exit(1, 1, 1); | |
| 108 | } | |
| 109 | @@ -535,6 +567,12 @@ | |
| 110 | if (keep_pcap) | |
| 111 | init_pcap(need_promiscuous(), netmask); | |
| 112 | ||
| 113 | + if (drop_privs) | |
| 114 | + drop_privileges(username); | |
| 115 | + | |
| 116 | + /* write the pid file after dropping privileges to be able to remove it later */ | |
| 117 | + write_pidfile(); | |
| 118 | + | |
| 119 | while (1) { /* MAIN EVENT LOOP */ | |
| 120 | libnet_t *l; /* to iterate through libnet context queue */ | |
| 121 | /* struct pcap_stat ps; */ /* to hold pcap stats */ | |
| 122 | @@ -1189,6 +1227,7 @@ | |
| 123 | fprintf(stderr, " -Q vlan_id tag outgoing frames with an 802.1Q VLAN ID\n"); | |
| 124 | fprintf(stderr, " -s capture_bufsize override default capture bufsize [%d]\n", CAPTURE_BUFSIZE); | |
| 125 | fprintf(stderr, " -T enable the socket receive timeout feature\n"); | |
| 126 | + fprintf(stderr, " -u username change uid after setup (use with -k\n"); | |
| 127 | fprintf(stderr, " -v display version number then exit\n"); | |
| 128 | fprintf(stderr, " -w cwd override default working directory [%s]\n", CWD); | |
| 129 | fprintf(stderr, " interface_name name of ethernet interface\n"); |