diff options
author | Kyle Gunger <kgunger12@gmail.com> | 2024-05-01 00:09:40 -0400 |
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committer | Kyle Gunger <kgunger12@gmail.com> | 2024-05-01 00:09:40 -0400 |
commit | 0c1b29f06ddcfda2cf47461f846ddee0a320567d (patch) | |
tree | b3d9d103ebf97a08c4bb3363b644eed2d217551d /src | |
parent | c0d309b3be94b89d421ab265ebdfc34438f5dfe6 (diff) |
init make
Diffstat (limited to 'src')
-rw-r--r-- | src/bind.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/src/bind.c b/src/bind.c new file mode 100644 index 0000000..2545003 --- /dev/null +++ b/src/bind.c @@ -0,0 +1,138 @@ +#include "osm/bind.h" + +#include <errno.h> +#include <stdio.h> +#include <unistd.h> + +#include <sys/socket.h> +#include <sys/un.h> + +/** + * The required characters to represent an id as a file name + * id - the id to get translated to a file name + */ +int _need_chars(int id) +{ + int i = 1; + + while (id > 15) + { + id /= 16; + i++; + } + + return i; +} + +/** + * Write the integer file name after the folder path. + * id - the id to get translated to a file name + * start - a pointer to just after the end of the folder path string + */ +void _write_name(int id, char *start) +{ + int i = _need_chars(id); + while (i > 0) + { + // Get current character + char c = '0'; + if (id % 16 < 10) + c += id % 16; + else + c = 'a' + (id % 16) - 10; + + // Put character + *(start + i - 1) = c; + + // divide id, sub from i + id /= 16; + i -= 1; + } +} + +/** + * Bind to the next available onboard socket in the given directory + * sock_dir - The directory containing osm sockets (or null for the default) + */ +int osm_bind_local(int sockfd, const char *sock_dir) +{ + struct sockaddr_un name; + name.sun_family = AF_LOCAL; + + strncpy(name.sun_path, sock_dir, sizeof(name.sun_path)); + name.sun_path[sizeof(name.sun_path) - 1] = 0; + + // Check for slash at end of path + int len = strlen(name.sun_path); + + if (name.sun_path[len - 1] != '/') + { + name.sun_path[len] = '/'; + len++; + } + + // check that we won't overflow the buffer + if (len > sizeof(name.sun_path) - 2) + { + return -1; + } + + // sequentially try to bind + int id = 0; + while(_need_chars(id) + len < sizeof(name.sun_path) - 1) + { + // write file name + _write_name(id, name.sun_path + len); + + // try to bind + int size = offsetof(struct sockaddr_un, sun_path) + strlen(name.sun_path); + + if (bind(sockfd, (struct sockaddr *) &name, size) > 0) + { + return 0; + } + + // inc id + id++; + } + + return -1; +} + +/** + * Bind a new onboard socket + * sock_dir - The directory containing osm sockets (or null for the default) + * return - a negitve number on error, or the socket fd on success + */ +int osm_open_onboard(char *sock_dir) +{ + int sockfd = socket(AF_LOCAL, SOCK_DGRAM, 0); + if (sockfd < 0) + { + perror("socket"); + return sockfd; + } + + int bound = -1; + if (sock_dir == NULL) + { + bound = osm_bind_local(sockfd, "/run/osm/onboard/"); + } + else + { + bound = osm_bind_local(sockfd, sock_dir); + } + + if (bound < 0) + { + perror("bind"); + close(sockfd); + return bound; + } + + return sockfd; +} + + + + |