agetty: stop using MAXHOSTNAMELEN

Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/term-utils/agetty.c b/term-utils/agetty.c
index 4e23135929ae523a1f33c336a1aef9b9acb4b65e..9bb0fd753ff08b2f60dfe5a8dba9b4e64dd1b66a 100644 (file)
--- a/term-utils/agetty.c
+++ b/term-utils/agetty.c
@@ -1220,6 +1220,41 @@ static void auto_baud(struct termios *tp)
        tcsetattr(STDIN_FILENO, TCSANOW, tp);
 }
 
+static char *xgethostname(void)
+{
+       char *name;
+       size_t sz = get_hostname_max() + 1;
+
+       name = malloc(sizeof(char) * sz);
+       if (!name)
+               log_err(_("failed to allocate memory: %m"));
+
+       if (gethostname(name, sz) != 0)
+               return NULL;
+
+       name[sz - 1] = '\0';
+       return name;
+}
+
+static char *xgetdomainname(void)
+{
+#ifdef HAVE_GETDOMAINNAME
+       char *name;
+       size_t sz = get_hostname_max() + 1;
+
+       name = malloc(sizeof(char) * sz);
+       if (!name)
+               log_err(_("failed to allocate memory: %m"));
+
+       if (getdomainname(name, sz) != 0)
+               return NULL;
+
+       name[sz - 1] = '\0';
+       return name;
+#endif
+       return NULL;
+}
+
 /* Show login prompt, optionally preceded by /etc/issue contents. */
 static void do_prompt(struct options *op, struct termios *tp)
 {
@@ -1293,12 +1328,12 @@ static void do_prompt(struct options *op, struct termios *tp)
        }
 #endif /* KDGKBLED */
        if ((op->flags & F_NOHOSTNAME) == 0) {
-               char hn[MAXHOSTNAMELEN + 1];
-               if (gethostname(hn, sizeof(hn)) == 0) {
+               char *hn = xgethostname();
+
+               if (hn) {
                        struct hostent *ht;
                        char *dot = strchr(hn, '.');
 
-                       hn[MAXHOSTNAMELEN] = '\0';
                        if ((op->flags & F_LONGHNAME) == 0) {
                                if (dot)
                                        *dot = '\0';
@@ -1308,6 +1343,7 @@ static void do_prompt(struct options *op, struct termios *tp)
                        else
                                write_all(STDOUT_FILENO, hn, strlen(hn));
                        write_all(STDOUT_FILENO, " ", 1);
+                       free(hn);
                }
        }
        if (op->autolog == (char*)0) {
@@ -1732,7 +1768,7 @@ static void output_iface_ip(struct ifaddrs *addrs, const char *iface, sa_family_
 
 static void output_ip(sa_family_t family)
 {
-       char host[MAXHOSTNAMELEN + 1];
+       char *host;
        struct addrinfo hints, *info = NULL;
 
        memset(&hints, 0, sizeof(hints));
@@ -1740,9 +1776,8 @@ static void output_ip(sa_family_t family)
        if (family == AF_INET6)
                hints.ai_flags = AI_V4MAPPED;
 
-       if (gethostname(host, sizeof(host)) == 0
-           && getaddrinfo(host, NULL, &hints, &info) == 0
-           && info) {
+       host = xgethostname();
+       if (host && getaddrinfo(host, NULL, &hints, &info) == 0 && info) {
 
                void *addr = NULL;
                char buff[INET6_ADDRSTRLEN + 1];
@@ -1760,6 +1795,7 @@ static void output_ip(sa_family_t family)
 
                freeaddrinfo(info);
        }
+       free(host);
 }
 
 /*
@@ -1814,36 +1850,32 @@ static void output_special_char(unsigned char c, struct options *op,
                break;
        case 'o':
        {
-               char domainname[MAXHOSTNAMELEN+1];
-#ifdef HAVE_GETDOMAINNAME
-               if (getdomainname(domainname, sizeof(domainname)))
-#endif
-               strcpy(domainname, "unknown_domain");
-               domainname[sizeof(domainname)-1] = '\0';
-               printf("%s", domainname);
+               char *dom = xgetdomainname();
+
+               fputs(dom ? dom : "unknown_domain", stdout);
+               free(dom);
                break;
        }
        case 'O':
        {
-               char *dom = "unknown_domain";
-               char host[MAXHOSTNAMELEN+1];
+               char *dom = NULL;
+               char *host = xgethostname();
                struct addrinfo hints, *info = NULL;
 
                memset(&hints, 0, sizeof(hints));
                hints.ai_flags = AI_CANONNAME;
 
-               if (gethostname(host, sizeof(host)) ||
-                   getaddrinfo(host, NULL, &hints, &info) ||
-                   info == NULL)
-                       fputs(dom, stdout);
-               else {
+               if (host && getaddrinfo(host, NULL, &hints, &info) == 0 && info) {
                        char *canon;
+
                        if (info->ai_canonname &&
                            (canon = strchr(info->ai_canonname, '.')))
                                dom = canon + 1;
-                       fputs(dom, stdout);
-                       freeaddrinfo(info);
                }
+               fputs(dom ? dom : "unknown_domain", stdout);
+               if (info)
+                       freeaddrinfo(info);
+               free(host);
                break;
        }
        case 'd':