From 995387d1f852c4301ef0685a91d3df38f4bcdc36 Mon Sep 17 00:00:00 2001 From: "Michael K. Johnson" Date: Thu, 18 Sep 1997 20:03:53 +0000 Subject: Support alternative device configurations. --- src/usernetctl.1 | 3 ++ src/usernetctl.c | 92 ++++++++++++++++++++++++++++++++++++++------------------ 2 files changed, 66 insertions(+), 29 deletions(-) (limited to 'src') diff --git a/src/usernetctl.1 b/src/usernetctl.1 index 1602f7b5..27287b68 100644 --- a/src/usernetctl.1 +++ b/src/usernetctl.1 @@ -16,3 +16,6 @@ The name of the network configuration file to read; for example, ifcfg-ppp0 .TP up\fI|\fPdown Attempt to bring the interface up or down. +.SH NOTES +Alternate device configurations may inherit the default configuration's +permissions. diff --git a/src/usernetctl.c b/src/usernetctl.c index 040aa2c9..33bdaf1c 100644 --- a/src/usernetctl.c +++ b/src/usernetctl.c @@ -3,6 +3,7 @@ #include #include #include +#include #include #include #include @@ -20,11 +21,49 @@ static char * safeEnviron[] = { NULL }; -int userCtl(char * file, int size) { +#define FOUND_FALSE -1 +#define NOT_FOUND 0 +#define FOUND_TRUE 1 + + +int testSafe(char * ifaceConfig) { + struct stat sb; + + /* these shouldn't be symbolic links -- anal, but that's fine w/ me */ + if (lstat(ifaceConfig, &sb)) { + fprintf(stderr, "failed to stat %s: %s\n", ifaceConfig, + strerror(errno)); + exit(1); + } + + /* safety checks */ + if (!S_ISREG(sb.st_mode)) { + fprintf(stderr, "%s is not a normal file\n", ifaceConfig); + exit(1); + } + + if (sb.st_uid) { + fprintf(stderr, "%s should be owned by root\n", ifaceConfig); + exit(1); + } + + if (sb.st_mode & S_IWOTH) { + fprintf(stderr, "%s should not be world writeable\n", ifaceConfig); + exit(1); + } + + return sb.st_size; +} + + +int userCtl(char * file) { char * contents; char * chptr; char * end; int fd; + int size; + + size = testSafe(file); contents = alloca(size + 2); @@ -51,18 +90,21 @@ int userCtl(char * file, int size) { while (chptr > contents && isspace(*chptr)) chptr--; *(++chptr) = '\0'; - if (!strcmp(contents, "USERCTL=yes")) return 1; + if (!strcmp(contents, "USERCTL=")) { + if (!strcmp(contents+8, "yes")) return FOUND_TRUE; + else return FOUND_FALSE; + } contents = end; } - return 0; + return NOT_FOUND; } + int main(int argc, char ** argv) { char * ifaceConfig; char * chptr; - struct stat sb; char * cmd; if (argc != 3) usage(); @@ -99,32 +141,24 @@ int main(int argc, char ** argv) { ifaceConfig = temp; } - /* these shouldn't be symbolic links -- anal, but that's fine w/ me */ - if (lstat(ifaceConfig, &sb)) { - fprintf(stderr, "failed to stat %s: %s\n", ifaceConfig, - strerror(errno)); - exit(1); - } - - /* safety checks */ - if (!S_ISREG(sb.st_mode)) { - fprintf(stderr, "%s is not a normal file\n", ifaceConfig); - exit(1); - } - - if (sb.st_uid) { - fprintf(stderr, "%s should be owned by root\n", ifaceConfig); - exit(1); - } - - if (sb.st_mode & S_IWOTH) { - fprintf(stderr, "%s should not be world writeable\n", ifaceConfig); - exit(1); - } - if (!userCtl(ifaceConfig, sb.st_size)) { - fprintf(stderr, "Users are not allowed to control this interface.\n"); - exit(1); + switch (userCtl(ifaceConfig)) { + char * dash; + case NOT_FOUND: + /* a `-' will be found at least in "ifcfg-" */ + dash = strrchr(ifaceConfig, '-'); + if (*(dash-1) != 'g') { + /* This was a clone configuration; ask the parent config */ + *dash = '\0'; + if (userCtl(ifaceConfig) == FOUND_TRUE) + /* exit the switch; users are allowed to control */ + break; + } + /* else fall through */ + case FOUND_FALSE: + fprintf(stderr, "Users are not allowed to control this interface.\n"); + exit(1); + break; } /* looks good to me -- let's go for it */ -- cgit v1.2.1