X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=src%2Foping.c;h=d27f187963dc511395c54bad8566f6f2c9d12562;hb=5a2d8718ca250276308a7e9a9395870de119b753;hp=3164230484a94f03e4eebb2175b5ae242b04b64c;hpb=77ec8f42e4efb20ee99c95a34c996891ff231501;p=liboping.git diff --git a/src/oping.c b/src/oping.c index 3164230..d27f187 100644 --- a/src/oping.c +++ b/src/oping.c @@ -31,6 +31,10 @@ # error "You don't have the standard C99 header files installed" #endif /* STDC_HEADERS */ +#if HAVE_UNISTD_H +# include +#endif + #if HAVE_MATH_H # include #endif @@ -54,8 +58,16 @@ # include #endif +#if HAVE_SYS_TYPES_H +#include +#endif + #include "oping.h" +#ifndef _POSIX_SAVED_IDS +# define _POSIX_SAVED_IDS 0 +#endif + typedef struct ping_context { char host[NI_MAXHOST]; @@ -73,6 +85,7 @@ typedef struct ping_context static double opt_interval = 1.0; static int opt_addrfamily = PING_DEF_AF; static char *opt_srcaddr = NULL; +static char *opt_device = NULL; static char *opt_filename = NULL; static int opt_count = -1; static int opt_send_ttl = 64; @@ -107,19 +120,29 @@ static void context_destroy (ping_context_t *context) free (context); } -static void usage_exit (const char *name) +static void usage_exit (const char *name, int status) { int name_length; name_length = (int) strlen (name); - fprintf (stderr, "Usage: %s [-46] [-c count] [-i interval]\n" - "%*s[-t ttl] [-I srcaddr]\n" - "%*s-f filename | host [host [host ...]]\n", - name, - 8 + name_length, "", - 8 + name_length, ""); - exit (1); + fprintf (stderr, "Usage: %s [OPTIONS] " + "-f filename | host [host [host ...]]\n" + + "\nAvailable options:\n" + " -4|-6 force the use of IPv4 or IPv6\n" + " -c count number of ICMP packets to send\n" + " -i interval interval with which to send ICMP packets\n" + " -t ttl time to live for each ICMP packet\n" + " -I srcaddr source address\n" + " -D device outgoing interface name\n" + " -f filename filename to read hosts from\n" + + "\noping "PACKAGE_VERSION", http://verplant.org/liboping/\n" + "by Florian octo Forster \n" + "for contributions see `AUTHORS'\n", + name); + exit (status); } static int read_options (int argc, char **argv) @@ -128,7 +151,7 @@ static int read_options (int argc, char **argv) while (1) { - optchar = getopt (argc, argv, "46c:hi:I:t:f:"); + optchar = getopt (argc, argv, "46c:hi:I:t:f:D:"); if (optchar == -1) break; @@ -146,6 +169,9 @@ static int read_options (int argc, char **argv) new_count = atoi (optarg); if (new_count > 0) opt_count = new_count; + else + fprintf(stderr, "Ignoring invalid count: %s\n", + optarg); } break; @@ -162,8 +188,8 @@ static int read_options (int argc, char **argv) double new_interval; new_interval = atof (optarg); if (new_interval < 0.001) - fprintf (stderr, "Ignoring invalid interval %g.\n", - new_interval); + fprintf (stderr, "Ignoring invalid interval: %s\n", + optarg); else opt_interval = new_interval; } @@ -176,6 +202,10 @@ static int read_options (int argc, char **argv) } break; + case 'D': + opt_device = optarg; + break; + case 't': { int new_send_ttl; @@ -183,14 +213,16 @@ static int read_options (int argc, char **argv) if ((new_send_ttl > 0) && (new_send_ttl < 256)) opt_send_ttl = new_send_ttl; else - fprintf (stderr, "Invalid TTL argument: %s\n", + fprintf (stderr, "Ignoring invalid TTL argument: %s\n", optarg); break; } case 'h': + usage_exit (argv[0], 0); + break; default: - usage_exit (argv[0]); + usage_exit (argv[0], 1); } } @@ -313,17 +345,42 @@ int main (int argc, char **argv) int optind; int i; + int status; +#if _POSIX_SAVED_IDS + uid_t saved_set_uid; + + /* Save the old effective user id */ + saved_set_uid = geteuid (); + /* Set the effective user ID to the real user ID without changing the + * saved set-user ID */ + status = seteuid (getuid ()); + if (status != 0) + { + fprintf (stderr, "Temporarily dropping privileges " + "failed: %s\n", strerror (errno)); + exit (EXIT_FAILURE); + } +#endif optind = read_options (argc, argv); - if (optind >= argc && !opt_filename) { - usage_exit (argv[0]); +#if !_POSIX_SAVED_IDS + /* Cannot temporarily drop privileges -> reject every file but "-". */ + if ((opt_filename != NULL) + && (strcmp ("-", opt_filename) != 0) + && (getuid () != geteuid ())) + { + fprintf (stderr, "Your real and effective user IDs don't " + "match. Reading from a file (option '-f')\n" + "is therefore too risky. You can still read " + "from STDIN using '-f -' if you like.\n" + "Sorry.\n"); + exit (EXIT_FAILURE); } +#endif - if (geteuid () != 0) - { - fprintf (stderr, "Need superuser privileges to open a RAW socket. Sorry.\n"); - return (1); + if ((optind >= argc) && (opt_filename == NULL)) { + usage_exit (argv[0], 1); } if ((ping = ping_construct ()) == NULL) @@ -361,29 +418,54 @@ int main (int argc, char **argv) } } + if (opt_device != NULL) + { + if (ping_setopt (ping, PING_OPT_DEVICE, (void *) opt_device) != 0) + { + fprintf (stderr, "Setting device failed: %s\n", + ping_get_error (ping)); + } + } + if (opt_filename != NULL) { FILE *infile; char line[256]; char host[256]; - if (strncmp(opt_filename, "-", 1) == 0) + if (strcmp (opt_filename, "-") == 0) + /* Open STDIN */ infile = fdopen(0, "r"); else infile = fopen(opt_filename, "r"); - if (!infile) + if (infile == NULL) { - fprintf (stderr, "Couldn't open file for hostnames: %s\n", strerror(errno)); + fprintf (stderr, "Opening %s failed: %s\n", + (strcmp (opt_filename, "-") == 0) + ? "STDIN" : opt_filename, + strerror(errno)); return (1); } +#if _POSIX_SAVED_IDS + /* Regain privileges */ + status = seteuid (saved_set_uid); + if (status != 0) + { + fprintf (stderr, "Temporarily re-gaining privileges " + "failed: %s\n", strerror (errno)); + exit (EXIT_FAILURE); + } +#endif + while (fgets(line, sizeof(line), infile)) { + /* Strip whitespace */ if (sscanf(line, "%s", host) != 1) continue; - if ((!*host) || (host[0] == '#')) + if ((host[0] == 0) || (host[0] == '#')) continue; if (ping_host_add(ping, host) < 0) @@ -395,9 +477,31 @@ int main (int argc, char **argv) } } +#if _POSIX_SAVED_IDS + /* Drop privileges */ + status = seteuid (getuid ()); + if (status != 0) + { + fprintf (stderr, "Temporarily dropping privileges " + "failed: %s\n", strerror (errno)); + exit (EXIT_FAILURE); + } +#endif + fclose(infile); } +#if _POSIX_SAVED_IDS + /* Regain privileges */ + status = seteuid (saved_set_uid); + if (status != 0) + { + fprintf (stderr, "Temporarily re-gaining privileges " + "failed: %s\n", strerror (errno)); + exit (EXIT_FAILURE); + } +#endif + for (i = optind; i < argc; i++) { if (ping_host_add (ping, argv[i]) < 0) @@ -409,8 +513,18 @@ int main (int argc, char **argv) } } - /* Drop root privileges if we're setuid-root. */ - setuid (getuid ()); + /* Permanently drop root privileges if we're setuid-root. */ + status = setuid (getuid ()); + if (status != 0) + { + fprintf (stderr, "Dropping privileges failed: %s\n", + strerror (errno)); + exit (EXIT_FAILURE); + } + +#if _POSIX_SAVED_IDS + saved_set_uid = (uid_t) -1; +#endif i = 0; for (iter = ping_iterator_get (ping);